Jobs Backend

We are looking for a Senior Ruby on Rails Developer to join a product engineering team working on a mature, high-traffic platform with a large and well-established domain model.

Project: A long-running digital platform in the travel, hospitality, and marketplace domain. The product manages complex workflows around properties, reservations, deposits and exchanges, billing, and member onboarding. You'll work on a large Ruby on Rails application, contributing to new features, performance improvements, integrations, and the continuous evolution of the platform.

Ability to maintain several hours of overlap with the CDT time zone.
 

This is a backend-focused Rails role. You'll work primarily with Ruby on Rails, databases, background processing, APIs, and third-party integrations while contributing to a large and established codebase.
Tech Stack: Ruby, Ruby on Rails 7.x, Rails Engines, MySQL, Redis, Memcached, Solr, Sidekiq, Clockwork, ActionCable, ActiveAdmin.
Authentication & Security: JWT, CanCan, bcrypt, role-based authorization.
Integrations: Stripe, AWS S3/CloudFront/SNS, Twilio, transactional email, product analytics, feature flags, geolocation.
Testing: Minitest, RSpec, FactoryBot, VCR/WebMock, Capybara/Selenium.
 

Responsibilities:
Develop and deliver backend features using Ruby on Rails;
Work effectively with a large, established Rails codebase and make well-tested, maintainable changes;
Design and implement database changes, models, service objects, APIs, and business logic;
Develop and maintain background jobs and scheduled processes using Sidekiq and related tools;
Build and maintain integrations with third-party services such as Stripe, AWS, and Twilio;
Write and maintain automated tests, including unit, integration, and API tests;
Analyze and optimize application performance across the database, search, caching, and background processing layers;
Contribute to improving system reliability, code quality, and maintainability;
Participate in code reviews and collaborate closely with other engineers and product teams.
 

Requirements:
-5+ years of professional experience with Ruby on Rails, including production experience with large, established applications;
-Strong experience with Ruby on Rails 7.x;
-Solid knowledge of MySQL and/or PostgreSQL, including schema design, migrations, indexing, and query optimization;
-Strong experience with Sidekiq or similar background job processing tools;
-Experience building and maintaining RESTful APIs;
-Experience integrating third-party services and APIs;
-Strong testing experience with Minitest/RSpec and related testing tools;
-Experience with Git and pull-request workflows;
-Comfortable working with and improving a large, long-lived codebase;
-Good written English and clear communication skills.

Nice to Have:
Experience with JavaScript, Vue, Stimulus, or Hotwire;
Experience with HTML, CSS, and Sass;
Experience with Solr, Elasticsearch, or other full-text search technologies;
Experience with Stripe or other payment and billing integrations;
Experience with ActiveAdmin or similar admin frameworks;
Familiarity with Docker and Kubernetes;
Familiarity with CI/CD, including CircleCI or GitHub Actions;
Familiarity with AWS, particularly S3, CloudFront, or SNS;
Experience with monitoring and observability tools such as Prometheus or APM solutions;
 

About Our Client:

Our client is a leading enterprise data platform company building an open, high-performance data lakehouse for AI and analytical workloads. The platform combines an intelligent SQL query engine, an AI-ready semantic layer, and an open catalog built on Apache Iceberg — enabling Fortune 500 companies across finance, energy, manufacturing, and logistics to unify, query, and govern data at massive scale across cloud and on-premise sources.

About the Role:

We are looking for a Senior Software Engineer for the connectivity stack of a large-scale data platform. The work spans three areas:

• Client connectivity — drivers and client libraries used by applications and BI tools
• Source connectivity — connectors to databases and data systems, including authentication, metadata discovery, and query/data pushdown, with certification and upgrade support
• Agent & service connectivity — tool interfaces and integrations for AI-agent access to the platform

Deep expertise in one of these areas is enough — you'll grow into the adjacent ones over time. This is a role for an engineer who cares about API and protocol stability, backward compatibility, and interoperability with the tools enterprises actually use. You will lead the design and delivery of substantial components, working within an established architecture alongside US-based engineering reviewers.

This is a systems-level, backend engineering role focused on drivers, protocols, and distributed services — not application development or CRUD services.

Responsibilities:

• Lead the design and delivery of connectivity components — client drivers, source connectors, and service integrations — turning ambiguous initiatives into well-scoped, reviewable milestones
• Produce technical designs, explain architectural trade-offs, and surface compatibility, security, and delivery risks early
• Maintain backward compatibility and API/protocol stability; build compatibility, interoperability, and performance test suites
• Develop and maintain connectors for major BI tools, collaborating with the technology partners behind them
• Diagnose complex client/server, protocol, and distributed-system failures; drive root-cause analysis of customer-reported and escaped defects
• Improve diagnostics, logging, observability, and supportability of the connectivity stack
• Contribute upstream to open-source projects (e.g., Apache Arrow) where agreed
• Mentor engineers, participate in code and design reviews, and communicate progress and risks clearly across a distributed team.

Required Qualifications:

• B.S. or M.S. in Computer Science, Computer Engineering, or a related field — or equivalent practical experience
• 8+ years of production software engineering experience
• Deep proficiency in Java or C++, and the ability to work effectively in another systems/services language
• Experience designing and debugging APIs, protocols, client libraries, or distributed services
• Strong fundamentals: data structures, concurrency, asynchronous programming, networking, and failure handling
• A track record of comprehensive testing — unit, integration, compatibility, and performance
• Experience with production CI/CD, release processes, and engineering quality controls
• Working knowledge of SQL
• Comfortable with AI-assisted development workflows — using modern AI tools productively while critically validating their output
• Clear written and verbal communication in a distributed engineering environment; English Upper-Intermediate or higher (B2+)
• Availability to work EU business hours shifted 2–3 hours later for daily overlap with US West Coast mornings.

Desired Skills:

• JDBC, ODBC, ADBC, or database-driver development experience
• Apache Arrow (including Arrow Flight)
• SQL engines, databases, or data platforms
• Source-connector development for databases, warehouses, or SaaS systems
• MCP or agent-tool integrations
• OAuth, OIDC, TLS, and enterprise authentication flows
• Cross-platform native build, packaging, and release experience
• BI-tool interoperability (Power BI, Tableau) and partner collaboration
• Observability and production diagnostics
• Open-source contribution experience.

Details:

• Engagement: Long-term contract
• Location: Europe (EU / EEA / UK), remote
• Working hours: EU business hours, shifted 2–3 hours later for daily overlap with the US West Coast team

About Our Client:

Our client is a leading enterprise data platform company building an open, high-performance data lakehouse for AI and analytical workloads. The platform combines an intelligent SQL query engine, an AI-ready semantic layer, and an open catalog built on Apache Iceberg — enabling Fortune 500 companies across finance, energy, manufacturing, and logistics to unify, query, and govern data at massive scale across cloud and on-premise sources.

About the Role:

We are looking for a Senior Software Engineer for the data catalog and enterprise data management layer of a large-scale lakehouse platform — the services that automate data ingestion and autonomously optimize Apache Iceberg tables. You will own features through the full development cycle, from design through deployment, in a multithreaded, distributed environment where scalability, performance, and always-on availability are the baseline expectations.

This is a systems-level, backend engineering role focused on data infrastructure internals — not application development or CRUD services.

Responsibilities:

• Own the full software development cycle — inception, design, development, testing, deployment — for catalog and data-management services
• Build and operate services for automated ingestion and autonomous optimization of Apache Iceberg tables
• Reason about concurrency and parallelization to deliver scalability and performance in multithreaded, distributed systems
• Drive performance tuning and system-efficiency improvements
• Work with Apache Foundation open-source projects, contributing upstream where agreed
• Participate in code and design reviews, upholding a high engineering bar
• Collaborate with product managers, support teams, and solution architects on feature requests and design updates
• Partner with US-based engineering leads on technical decisions.

Required Qualifications:

• B.S., M.S., or PhD in Computer Science or a related field
• 5+ years of software engineering experience, preferably focused on database systems or related fields
• Strong object-oriented programming skills in Java or C++
• Solid grounding in data structures and algorithms
• Hands-on experience with multithreaded and asynchronous programming patterns for scalable, performant systems
• A passion for engineering quality — zero-downtime upgrades, availability, resiliency, and uptime as first-class concerns
• Comfort with a fast-moving environment; strong ownership; the confidence to defend a technical position and the openness to be mentored
• Comfortable with AI-assisted development workflows — using modern AI tools productively while critically validating their output
• English Upper-Intermediate or higher (B2+) — daily written and verbal communication with a US-based engineering team
• Availability to work EU business hours shifted 2–3 hours later for daily overlap with US West Coast mornings.

Desired Skills:

• Database internals and query planning
• Distributed systems: concurrency control, data replication, storage systems
• Apache Iceberg or other open table formats (Delta Lake, Hudi)
• Messaging systems: Kafka, NATS, or cloud pub/sub services
• Contributions to open-source data infrastructure (Apache projects especially valued).

Details:

• Engagement: Long-term contract
• Location: Europe (EU / EEA / UK), remote
• Working hours: EU business hours, shifted 2–3 hours later for daily overlap with the US West Coast team

About Our Client:

Our client is a leading enterprise data platform company building an open, high-performance data lakehouse for AI and analytical workloads. The platform combines an intelligent SQL query engine, an AI-ready semantic layer, and an open catalog built on Apache Iceberg — enabling Fortune 500 companies across finance, energy, manufacturing, and logistics to unify, query, and govern data at massive scale across cloud and on-premise sources.

About the Role:

We are looking for a Senior Software Engineer to build and operate production AI agent and search services on top of a large-scale data platform. This is hands-on work at the intersection of distributed backend engineering and applied AI: multi-agent workflows, tool-execution infrastructure, retrieval and relevance, and integrations with multiple LLM providers — all running as real, customer-facing production services with the reliability expectations that implies.

Responsibilities:

• Design and implement scalable multi-agent workflows (including conversation state), tool-execution infrastructure, and data-aware tools working with catalogs, schemas, lineage, SQL, jobs, semantic metadata, data preparation, and visualizations
• Build search and retrieval capabilities with OpenSearch or equivalent — indexing, relevance tuning, hybrid keyword + vector search
• Integrate multiple LLM/model providers with secure configuration and graceful degradation
• Develop APIs and event contracts across REST, streaming/SSE, gRPC, protobuf, and SDKs, including UI integrations
• Operate, monitor, and improve production services — service health, logs, metrics, traces, search-cluster health, latency, and error rates; participate in the team's production-support model
• Investigate incidents, drive root-cause analysis, and ship durable fixes
• Design for permissions, tool approvals, multi-tenancy, and customer-data governance
• Maintain dependencies, apply security fixes, and reduce tech debt; produce designs, tests, runbooks, and documentation; lead technical discussions and review code.

Required Qualifications:

• B.S. or M.S. in Computer Science, Computer Engineering, or a related field — or equivalent practical experience
• 7+ years of relevant experience, or equivalent demonstrated senior-level impact
• Strong Java software engineering skills
• Strong grasp of concurrency, data structures, API design, testing, maintainability, and backward compatibility
• Solid background in distributed systems, microservices, cloud services, or data-intensive backends
• Hands-on experience with search technologies — OpenSearch, Elasticsearch, or Lucene — including vector search, embeddings, or relevance systems
• Experience building LLM applications, agent/tool workflows, RAG systems, or model-provider integrations
• Strong production instincts: diagnosing failures via logs, metrics, and traces; designing for fault tolerance, retries, cancellation, and recovery
• SQL and familiarity with data platform concepts: catalogs, metadata, schemas, governance, lineage
• Comfort leading ambiguous, cross-service work with clear stakeholder communication and strong written documentation
• Comfortable with AI-assisted development workflows — using modern AI tools productively while critically validating their output
• English Upper-Intermediate or higher (B2+) — daily written and verbal communication with a US-based engineering team
• Availability to work EU business hours shifted 2–3 hours later for daily overlap with US West Coast mornings.

Desired Skills:

• LangChain4j or similar agent frameworks
• Python for AI services, evaluation harnesses, or sandboxed execution
• React and TypeScript
• gRPC, protobuf, Quarkus, Kubernetes, MongoDB, KV stores, event-driven architectures
• Apache Arrow, Apache Iceberg, OpenLineage, semantic layers, or data-governance systems
• AI quality evaluation: LLM-as-judge, model benchmarking, production AI metrics
• OpenSearch operations: index lifecycle management, relevance tuning, incident response
• Open-source contributions.

Details:

• Engagement: Long-term contract
• Location: Europe (EU / EEA / UK), remote
• Working hours: EU business hours, shifted 2–3 hours later for daily overlap with the US West Coast team

Project Description:

Luxoft is seeking motivated Appian developers to join our expanding Appian Digital Automation Practice in India. You will have the opportunity to work with our global clients on digital transformation initiatives and contribute to the Appian Center of Excellence for our customers.

You will collaborate with high-caliber project teams composed of engineers with deep technical expertise and domain knowledge, providing significant opportunities for learning, growth, and career advancement. We support cross-training in BPM, RPA, and related technologies through certification reimbursement programs.

Luxoft offers a competitive compensation and benefits package, including industry-leading insurance coverage in India. As you advance your career with Luxoft, you may also have the opportunity to pursue roles at our international offices through our Internal Mobility program.

Responsibilities:

- Collaborate with business partners to gather and analyze requirements.

- Design, develop, configure, test, deploy, implement, maintain, and enhance custom BPM workflows using Appian across the enterprise.

- Design and implement complex enterprise integrations with LDAP, Active Directory, and other internal systems.

- Design and develop database objects to support BPM applications.

- Maintain database performance by identifying and resolving production and development issues.

- Participate in workflow analysis and modeling using SQL Server and SQL Management Studio.

- Translate BPM requirements into Appian process model prototypes and solutions ensuring quality and performance.

- Deliver projects using Agile or Waterfall methodologies as specified.

- Conduct and participate in detailed design reviews to ensure compliance with approved architecture.

- Engage in daily activities of the Appian BPM development teams.

- Support enhancements to Appian applications, user access management, deployments, and database performance management.

- Collaborate with application support teams during development, deployment, and support phases.

Mandatory Skills Description:

• Possess a bachelor's degree in Computer Science, Engineering, or a related technical field from an accredited university or college..

• Have 4-6 years of software engineering experience, demonstrating proficiency in one or more of the following technologies: Appian, Scripting, REST API services, Java and JavaScript.

• Completed end-to-end implementation for at least 2 real-life Appian projects.

• Exhibit expertise in integrations utilizing Web API, Integrations, with the capability to tailor these functionalities to suit external system requirements.

• Showcase a robust grasp of database principles, coupled with practical experience in Stored Procs, MySQL or SQL Server.

• Demonstrate experience in Appian Process Models, Rules & Expressions, Data Management including Complex Data Types, XSDs, SQL, Inter Process Communication, RBAC, and Process Reporting on Appian 20.X and above.

• Possess Appian Certification as per your experience level.

• Embrace an agile mindset and have a level of familiarization with Agile methodologies along with having a knack for crafting solutions that facilitate business process automation.

• Offer a blend of technical prowess, strong business acumen, leadership abilities, and a track record of effective knowledge transfer.

Nice-to-Have Skills Description:

SQL, Integrations, Agile Methodology, Scripting

 Hi! We are looking for a Senior Node.js Backend Developer (Payments Platform) to join our pack at SharksCode 🦈💙
 SharksCode is a Ukrainian IT company that develops high-tech software solutions and scalable B2B platforms.
 We are looking for a Senior Node.js Backend Developer who will help build and evolve our payment platform, working on scalable backend services, distributed systems, and integrations with external financial providers. In this role, you will participate in architectural decisions, develop secure and reliable payment flows, and contribute to building resilient, high-load backend services.

We expect that you:

• Have 6+ years of commercial backend development experience with Node.js.
• Have strong commercial experience with TypeScript and a deep understanding of its type system.
• Have hands-on experience designing and developing REST APIs.
• Write clean, maintainable, well-tested, and production-ready code.
• Have experience decomposing complex business requirements into scalable technical solutions.
• Can clearly explain and justify technical decisions, trade-offs, risks, and alternative approaches.
• Have strong practical experience with PostgreSQL, including query optimization, indexing, schema design, and performance tuning under high load.
• Have hands-on experience designing and developing microservice-based distributed systems.
• Understand distributed and event-driven architectures.
• Have practical experience working with Kafka.
• Have hands-on experience using Redis.
• Have experience implementing retries, timeouts, circuit breakers, rate limiting, and backpressure mechanisms.
• Have experience integrating third-party APIs, including payment providers, PSPs, banks, KYC providers, or other external services.
• Have a solid understanding of secure software development principles.
• Have practical knowledge of OAuth 2.0, JWT, HMAC, mTLS, API authentication, and authorization.
• Can identify security vulnerabilities in code, APIs, dependencies, configurations, and system architecture.
• Have experience conducting code reviews and technical audits of backend services.
• Understand principles of protecting personal, payment, and other sensitive data.
• Have a strong understanding of HTTP/HTTPS, TCP/IP, DNS, Webhooks, and the lifecycle of network requests.
• Understand TLS/mTLS, certificate lifecycle management, rotation, and secure certificate storage.
   

Your future responsibilities:

• Design, develop, and maintain backend services for the payment platform.
• Build reliable integrations with payment providers, banks, and external financial services.
• Develop scalable microservices and distributed backend components.
• Participate in architecture discussions and contribute to technical decision-making.
• Optimize PostgreSQL performance and ensure system reliability under high load.
• Ensure backend security and compliance with engineering best practices.
• Conduct code reviews and contribute to improving engineering standards within the team.
• Collaborate closely with product, QA, and infrastructure teams to deliver reliable production solutions.
   

Nice to have:

• Experience with GraphQL or gRPC.
• Experience building payment platforms, financial services, or payment processing systems.
• Experience in iGaming, Betting, FinTech, Banking, or E-commerce domains.
• Understanding of payment lifecycle concepts such as authorization, capture, void, refund, reversal, and chargeback.
• Understanding of reconciliation, settlement, payment routing, and cascading.
• Knowledge of PCI DSS, KYC/AML, and secure payment data processing.
• Experience with observability tools such as Prometheus, Grafana, OpenTelemetry, Loki, or Jaeger.
• Experience mentoring engineers and improving engineering practices.
• Understanding of threat modeling, attack surface analysis, secrets management, and the principle of least privilege.
   

Interview stages:
🤝 Interview with Recruiter.
🧠 Technical Interview.
💙 Offer.

We offer:
🌴 24 paid vacation days, 14 sick days, and 5 days off.
⏰ Flexible start of the working day — from 9:00 to 11:00.
🏥 Medical insurance.
💰 Bonuses and performance-based rewards.
🐶 Office in the center of Kyiv — pets are welcome, we are pet-friendly.
💆 Lounge area in the office to recharge during the day.
🎾 Padel tennis, football, and training at the polygon for those who enjoy active leisure.
📚 Learning compensation, internal meetups and workshops, as well as access to the corporate LMS with courses.
🎁 Corporate currency that can be exchanged for merch, gifts, or additional benefits.

Are you passionate about building reliable Back-end systems and solving complex engineering challenges at scale? We are looking for a Senior Golang Engineer to join a high-impact cybersecurity project focused on protecting applications from automated attacks and malicious traffic.

You will become part of a small autonomous engineering team working with a large ecosystem of services, including legacy and modern distributed systems. This role is ideal for engineers who enjoy technical ownership, architecture improvements, and influencing product direction through strong engineering practices.

We at Sigma Software offer the opportunity to work on meaningful products used globally, collaborate with experienced engineers, and contribute to long-term platform evolution in a flexible remote environment.

Customer

Our Customer is a global cybersecurity company delivering advanced digital protection solutions for individuals, businesses, and communities. The company develops products focused on identifying vulnerabilities, preventing cyber threats, and ensuring secure digital experiences across multiple industries. Their solutions operate at scale and protect high-traffic environments against modern security risks and automated attacks.

Project

The project focuses on building and improving a platform that safeguards applications from automated attacks and malicious traffic. The engineering team works with approximately 35 Back-end services, combining legacy systems and modern distributed architecture. You will contribute to platform scalability, reliability, and long-term maintainability while partnering closely with product and engineering teams.

Requirements

• 5+ years of commercial software development experience
• Strong proficiency in Golang
• Strong computer science fundamentals including algorithms, data structures, and system design
• Experience across the full software development lifecycle, from planning and objective-setting to delivery and support
• Proven experience working with high-load, high-traffic production systems
• Solid understanding of scalable and maintainable backend architecture principles
• Ability to independently work with large and unfamiliar codebases
• Strong analytical and problem-solving skills
• Demonstrated proactive mindset with the ability to identify issues before escalation
• Experience aligning technical solutions with business and customer needs
• Ability to effectively communicate and negotiate technical direction with engineering stakeholders

• Upper-Intermediate English level

   

Will be a plus

• Experience with C++, Objective-C, or Rust
• Previous experience as a primary owner of a large-scale legacy system
• Experience working within cybersecurity or infrastructure-focused products

• Background in distributed systems and service-oriented architectures

   

Personal Profile

• Highly proactive and self-driven engineer
• Strong ownership mentality
• Confident in making technical decisions and defending architectural approaches
• Comfortable working in ambiguous and complex environments
• Strong collaboration and communication skills
• Focused on long-term quality and engineering excellence

Responsibilities

• Independently own and navigate a large backend ecosystem consisting of multiple services with minimal ramp-up support
• Develop and maintain backend services using Golang
• Write clean, scalable, and maintainable code while actively participating in code reviews and technical discussions
• Analyze legacy and unreviewed code to identify technical debt, systemic issues, and architectural risks
• Proactively identify inefficiencies, gaps, and areas for improvement, proposing and implementing solutions
• Collaborate with engineering and product teams to define technical objectives and execute roadmap initiatives
• Advocate for architectural improvements and negotiate technical decisions with peer engineering teams
• Contribute to long-term platform evolution while balancing short-term business priorities
• Ensure reliability and performance of high-load production systems

Job Description

• 6+ years of experience in backend microservices architecture, with a specialized focus on modern C# .NET frameworks and cloud ecosystems.
• Strong proficiency in C# 12, .NET 8, Kestrel web server, and Python FastAPI microservices.
• Deep expertise in relational database design (Azure SQL MI), ORM pattern design, SQL performance optimization, and integration with cloud data warehouses (Snowflake).
• Proven experience in designing and securing RESTful APIs, utilizing Azure API Management as an API Gateway, and managing asynchronous event messaging via Azure Service Bus.
• Expert-level knowledge of backend unit testing frameworks (xUnit, Pytest) and static code analysis enforcement using SonarQube.
• Solid background in cloud security, identity integration (Azure Entra External ID), Azure RBAC, Managed Identities, custom authorization microservices, and secrets management via Azure Key Vault.
• Practical experience implementing distributed caching (Azure Cache for Redis), dynamic app configurations, feature flag management, and task scheduling (Azure Logic Apps).
• Solid understanding of enterprise integration patterns, headless commerce storage (Shopify), Blob Storage, and microservices observability (Azure App Insights, Log Analytics).
• Self-organized personality with strong verbal/written communication skills for leading technical teams and coordinating with cross-functional leads.

Job Responsibilities

• Define the end-to-end backend system architecture, API schemas, microservice boundaries, data contracts, and integration workflows.
• Develop, configure, and maintain high-throughput C# .NET 8 core microservices and Python FastAPI services for GenAI and search endpoints.
• Implement asynchronous messaging structures, event queues via Azure Service Bus, distributed caching strategies using Azure Cache for Redis, and scheduled Logic Apps jobs.
• Design and optimize database access models, data schemas in Azure SQL MI, and data sync mechanisms feeding into Snowflake data warehousing.
• Work closely with frontend leads, Solution Architects, DevOps engineers, and AI specialists to guarantee seamless data flow and endpoint performance.
• Address backend security vulnerabilities, enforcing fine-grained authorization policies, token validation via Azure Entra External ID, and secure Key Vault secret handling.
• Apply engineering techniques to optimize database query execution, memory management, low-latency API response rates, and telemetry data processing.
• Deliver technical guidance to backend developers, conduct rigorous code reviews, establish testing practices (xUnit, Pytest), and collaborate directly with product and engineering management.

Department/Project Description

Our client is developing an advanced industrial asset intelligence platform engineered to drive digital aftermarket transformation and equipment lifecycle monetization. The system integrates edge hardware telemetry, on-premise production software, cloud data warehouses, and generative AI to deliver a unified real-time asset tracking, service optimization, and aftermarket commerce experience for factory operators, field service engineers, and distributors.
The platform architecture centers on a distributed, cloud-native microservices backend built on C# 12 using .NET 8, Python FastAPI services, Azure SQL Managed Instance, Snowflake data warehousing, Azure Cache for Redis, Azure Service Bus, and Azure API Management.
The engineering initiative focuses on architecting high-performance RESTful APIs, designing secure data persistence layers, establishing event-driven messaging pipelines, integrating Azure OpenAI diagnostic APIs, managing custom authorization services, and orchestrating backend services with third-party platforms such as Shopify and SAP.

We build internal products and automation for our own teams to improve day-to-day business processes. Most tasks revolve around processing large datasets (millions of rows) and turning them into reliable, reusable outputs.

You'll work 50/50 between Python development and data work: building scripts/services and data pipelines, mainly with Pandas, plus some SQL and PySpark.

    What You'll Do

• Build internal tools and automation around data processing and reporting.
• Develop and maintain pipelines that ingest data from APIs and large files.
• Transform and validate data using Pandas; write clean, tested, maintainable Python.
• Use SQL mainly to extract data and for joins/aggregations when needed.
• Contribute to large-scale processing (PySpark/Spark) when applicable.

• Refactor and optimize existing scripts and pipelines; improve performance, readability, and reliability (tests/logging).

   

    What We're Looking For

• 2+ years of experience with Python in production.
• Strong Pandas: efficient transformations, joins/merges, memory/performance considerations.
• Solid engineering habits: tests, code review, debugging, and readable code.
• Working knowledge of SQL (MS SQL Server is our primary DB, but any RDBMS is fine).
• Comfortable with Linux and Git; daily tooling skills (e.g., VS Code).
• Excellent organizational and task management abilities.
• Self-motivated with the ability to work independently.
• Good written and spoken English communication skills.

    Nice to Have

• PySpark/Spark and/or Hadoop exposure; distributed processing concepts.
• Azure experience (storage/compute) or participation in on-prem → cloud initiatives; workflow orchestration is a plus.
• Data modeling fundamentals and basic ML understanding; а portfolio (GitHub/website) or examples of end-to-end projects/products (clean repo structure, README, tests) is a plus.

About B2Spin

We are B2Spin, and we are dedicated to delivering the best Free-to-Play Social Casino and gaming experiences by creating captivating, engaging, and unique products that are accessible to everyone. We have built a team of talented professionals from all over the globe, who are working to continually improve the experiences of our players. We are not looking to just be part of the industry, but to revolutionize it.

AI-Driven Engineering Culture

We are actively building an AI-driven engineering organization with a clear and deliberate stance: artificial intelligence is a core part of how we build and deliver software — not an experiment, not a trend, and not an optional add-on.

AI is embedded into our engineering workflows, from system design and prototyping to refactoring, testing, and code review. We expect engineers to be fully comfortable working in AI-driven environments and to treat AI as a primary productivity multiplier. Strong engineering judgment, architectural ownership, and accountability remain essential—AI amplifies our engineers, it doesn’t replace responsibility for technical decisions.

What you will be doing
• Design, evolve, and maintain core libraries, framework extensions, and shared components used across all engineering teams
• Take ownership of system performance, scalability, and high-load architecture, ensuring core services can handle massive throughput with low latency
• Proactively monitor production behavior, investigate complex application/database performance bottlenecks, and introduce advanced metrics, dashboards, and alerting systems
• Establish and advocate for best practices in concurrency, memory management, and resource utilization across the backend ecosystem
• Collaborate with cross-functional teams including backend, web, mobile, QA, and product teams
• Take ownership of specific functional areas within our large-scale architecture
• Leverage AI tools and assistants as integral parts of your development workflow—from system design to code review
• Contribute to maintaining high test coverage, predictable production behavior, and seamless scalability
• Drive engineering excellence through modern practices and continuous improvement

What we are looking for
• Deep, low-level understanding of Java internals (JVM, GC behavior, memory management, concurrency/multithreading, and performance profiling)
• Advanced knowledge of relational databases (PostgreSQL), including query optimization, indexing strategies, locking mechanisms, and connection pooling under heavy load and distributed systems architecture, specifically high-throughput event streaming with Kafka (partitioning, replication, consumer group rebalancing, and tuning).
• Strong system design, troubleshooting and debugging capabilities
• Comfortable and proactive in using AI coding assistants (GitHub Copilot, Claude Code, etc.) as productivity multipliers
• Practical experience validating, refining, and taking ownership of AI-generated output
• Upper-intermediate or higher level of English

Nice to have:
• Proven track record of building or maintaining shared libraries, SDKs, or internal tooling in a large-scale engineering organization.
• Hands-on experience with APM tools and observability stacks (Prometheus, Grafana, ELK) with the ability to define meaningful SLOs/SLIs, custom metrics, and proactive alerts.

Main technologies: Java, Spring, Spring Boot, Ebean-ORM, Quartz, Maven, Resteasy, Flyway, PostgreSQL 15, HTTP/Websockets, Netty, K8S/Docker, GCP, Jenkins, ELK, Grafana.

Numerical Technologies Ltd is a leading provider of custom software solutions and services specializing in risk, limits, and regulatory capital. Right now, we are looking for a Principal Java Engineer to join our team.

What you will be doing:

As part of the team, you will contribute to a strategic modernization initiative for a leading multinational financial services company. You will design, develop, and support scalable Java solutions while making key architectural decisions as the platform evolves from a monolithic application to a microservices architecture.

Working closely with product and engineering teams, you will design new service-based solutions, define service boundaries and integrations, build fault-tolerant services, and ensure high code quality through testing, code reviews, and system design.

Project: Modernization of a monolithic platform into a microservices architecture. Java services provide authentication, logging, and data management, while Python services implement core computational logic. The role combines hands-on development with architectural ownership of new solutions derived from existing business capabilities.

What we’re looking for:

• 5+ years of experience in Java development, preferably in FinTech.
• Strong experience with Java and Spring Framework.
• Solid understanding of microservices architecture and design patterns.
• Proficient in SQL (Oracle, PostgreSQL).
• AWS experience and Python knowledge are a plus.
• Ability to work independently and take ownership of technical and architectural decisions.
• Bachelor's degree or higher required.
• Upper-intermediate English level or higher.

What we offer:

• Competitive compensation depending on experience and skills.
• Regular assessments and salary reviews.
• Paid personal days.
• Mental health support program.
• Partial gym compensation.
• Language classes.
• Flexible working schedule.

Project Description:

One of the world's largest providers of products and services to the energy industry has a need to develop and support enterprise information system in Oil & Gas domain.

Product being developed is a cloud solution for interpretation of geological and geophysical data. Project is based on SCRUM methodology.

Our project is stable, long-term and constantly adopts new technologies such as newest Java and Eclipse RCP versions, cloud and GPU computing, microservices architecture and other innovative frameworks.

Work supposes close cooperation with Customer team located in Houston and following Agile principles.

Our team is senior, supportive and friendly.

Responsibilities:

• Collaborate closely with geophysicists, data scientists, and software engineers to translate scientific domain requirements into robust on-prem or Cloud software solutions.

• Design, develop, and maintain high-performance applications for geophysical and geological data analysis, interpretation and visualization

• Present architectural designs and technical proposals to the architecture review board.

• Ability to break down development tasks and lay out clear implementation roadmaps.

• Implement and optimize computation algorithms

• Design and develop both thin and thick client applications that interact with cloud-based microservices.

• Ensure high code quality through unit testing, code reviews, security hardening and continuous integration with other domain tools

• Provide technical support and lead user troubleshooting sessions to resolve issues and ensure smooth operation of DSG application.

• Mentor junior developers and actively contribute to architectural and

implementation decisions.

• Embrace Agile/Scrum methodologies, delivering and demonstrating working solutions at the end of each sprint

• Stay current with emerging technologies and trends in geophysical computing and software development.

Mandatory Skills Description:

At least 5-10 years of experience

GIS Java Eclipse

ESRI ArcGIS Runtime

ESRI Services and Authentication

Nice-to-Have Skills Description:

DSG experience

Oil and Gas experience is preferred but not mandatory

Languages:

English: B2 Upper Intermediate

Responsibilities

• Extract Revit and IFC model data—properties, parameters, type/instance data, and relationships—using Autodesk Platform Services APIs
• Transform extracted model data into structured, analysis-ready formats such as Parquet, JSON, or CSV
• Process and manage derived geometry data (SVF/SVF2, OBJ, STL, IFC) for downstream analysis and visualization
• Build and maintain geometry data checks, including proximity/clash detection, bounding-box and volume validation, missing-element detection, and parameter completeness
• Run IFC quality checks to validate schema conformance, property-set completeness, and geometry integrity
• Develop and operate robust data ingestion pipelines, handling asynchronous translation jobs, webhooks, retries, and large/heavy models
• Map BIM data semantics onto the platform’s structured data model and identify API coverage gaps
• Collaborate with data, engineering, and AEC domain teams to ensure extracted data accurately reflects model intent
 

Required Skills

• Strong backend/data engineering skills in Python
• Experience with Autodesk Platform Services (APS) APIs (Model Derivative, Data Management)
• Proficiency in extracting and transforming BIM data from Revit and IFC models
• Familiarity with IFC schema, Revit property/parameter structures, and BIM data semantics
• Ability to handle and process geometry data (meshes, transforms, spatial queries)
• Experience with data formats such as JSON, Parquet, and CSV
• Knowledge of analytical/columnar data querying
• Experience with asynchronous pipelines, webhooks, and cloud-based data processing
• Familiarity with tools like trimesh, shapely, IfcOpenShell, or xBIM
• Git proficiency for version control

Responsibilities

• Architect and implement backend systems for AI agent orchestration, including workflow logic, task routing, and error handling
• Design and build scalable, containerized microservices to support real-time data processing and high-concurrency requests
• Develop secure API gateways and data access layers for integration with enterprise systems such as SAP S/4HANA, Ariba, and external data providers
• Create backend logic for knowledge retrieval, including integration with vector databases and retrieval-augmented generation (RAG) models
• Construct connectors for external data feeds, managing rate limiting, caching, and data normalization
• Implement security controls such as authentication, RBAC, and data redaction to meet defense-grade requirements
• Optimize backend systems for on-premise and air-gapped deployments, ensuring efficient resource usage and reliability
• Establish comprehensive logging, monitoring, and observability to support operational excellence and compliance
• Collaborate with cross-functional teams to deliver robust, production-ready backend solutions for AI-driven platforms
   

Required Skills

• Expert proficiency in Python (FastAPI or Django)
• Strong experience with Go or Java for high-performance microservices
• Deep knowledge of Docker and Kubernetes for containerization and orchestration
• Advanced skills in designing RESTful APIs and gRPC services
• Experience building and managing API Gateways (e.g., Kong, NGINX)
• Proficiency with PostgreSQL and vector databases (e.g., Weaviate, Milvus)
• Familiarity with enterprise integration protocols (OData, SOAP)
• Strong understanding of authentication, RBAC, and data security best practices
• Experience deploying and optimizing systems in on-premise or air-gapped environments
• Proven ability to implement logging, monitoring, and observability in production systems

We are a Ukrainian outsourcing company Join.To.IT, founded in 2012, and delivering software solutions across diverse business domains.
We focus on building long-term partnerships with our clients and delivering solutions that create real business impact. Our team consists of experienced professionals who take ownership of their work, value clear communication, and are committed to high standards in everything they do.
At Join.To.IT, we create an environment where engineers can grow, influence technical decisions, and contribute to meaningful projects alongside a strong and supportive team. 

Responsibilities

• Develop and maintain backend functionality primarily using Python
• Work with an additional backend technology/stack depending on project needs
• Support, improve, and scale existing backend projects and solutions
• Design and integrate APIs, services, and backend components
• Participate in project estimation, technical planning, and solution design
• Conduct code reviews and maintain code quality standards
• Collaborate with cross-functional teams to deliver scalable and efficient solutions
• Understand project business logic and translate requirements into technical solutions

Requirements

• 1+ years of commercial experience in backend development
• Strong commercial experience with Python
• Commercial experience with at least one additional backend stack: Node.js/TypeScript, PHP, Java, Go, C#/.NET, or similar
• Intermediate (B1+) English or higher
• Experience with Python frameworks: Django, DRF, and/or FastAPI
• Strong knowledge of databases: PostgreSQL, Redis
• Experience with REST APIs and backend integrations
• Experience using AI-assisted development tools/agents such as Claude Code, Cursor, Windsurf, Codex, Antigravity, or similar
• Familiarity with Docker and basic DevOps practices
• Ability to estimate development tasks and participate in project planning
• Good understanding of business logic and software development processes
• Strong communication and teamwork skills

Nice to Have

• Experience working commercially with 1+ backend languages/stacks
• Basic Frontend knowledge
• Experience with microservices architecture
• Experience with cloud platforms (AWS, GCP, or Azure)
• CI/CD experience

We Offer

• Office-based or remote work format (Kyiv, near Vasylkivska metro station)
• Working hours: 10:00–19:00, Monday–Friday
• Comfortable office with a shelter, Starlink, and uninterrupted power supply
• Medical insurance
• Free gym access near the office
• Paid vacation and sick leave
• Compensation for professional courses and development
• Supportive and loyal management