Jobs Backend

We are a senior engineering team hiring a backend engineer for a long-term role inside a client's product team. The client is a product company with a large user base. We share its name only with engineers who pass our technical call.

Engineers there shape what gets built, not only how, and work directly with product people.

The product's image and video generation runs on ComfyUI workflows, so hands-on ComfyUI is a must for this role.

What matters most to us
• You have built or run ComfyUI workflows yourself, with models deployed locally and custom nodes in the pipeline
• You have built a product that people use every day, and you can point to the parts you owned
• You think about the person using the product. You question a feature when it does not serve them and suggest a better one
• Experience with consumer products built around image or video is a strong plus

What you will do
• Build and run ComfyUI workflows for image and video generation
• Build and scale the backend services around them in Go
• Run background jobs reliably, with queues, retries and idempotent steps
• Turn new models into features people actually use

You should have
• Hands-on ComfyUI, at least on your own projects
• 3+ years of Go in production and 5+ years of backend work overall. 
• Experience owning parts of a production system end to end
• Fluent English for daily work with the client team

The role is full time, 40 hours a week, long term, with a working day that overlaps European business hours. Individual engineers only, no agencies.

How we hire: a call with our CTO about your ComfyUI work, your product work and your code, then a call with the client's team. Both are live, with screen share and without AI assistants.

To apply, open your application with a link to a ComfyUI workflow you built or ran, or one sentence on what it did. Applications without it will not be read.

We're looking for a mid-to-senior Platform Engineer to join an early-stage AI company in Stockholm. The company builds agentic AI for intellectual property and legal teams, and its platform serves Fortune 500 customers with long-running, document-heavy workloads. The purpose of the hire is to own the Kubernetes platform underneath the product. As concurrent agent sessions grow from hundreds to thousands, you'll keep the infrastructure fast, secure and resilient. We want a software engineer at heart who builds the platform as code and cares about reliability, performance and cost.

Role at a glance

• Location: Stockholm, Sweden (on-site)
• Employment: Full-time
• Seniority: Mid-Senior
• Core stack: Kubernetes, Azure, Terraform / Infrastructure as Code, TypeScript, Python, distributed systems

What you'll do

• Own and evolve the Kubernetes platform for heavy, long-running workloads
• Design and scale distributed systems that handle unpredictable load
• Build the services that run the platform, in TypeScript and/or Python
• Automate infrastructure with Infrastructure as Code
• Balance reliability, performance and cost with a product mindset

Must have

• Deep expertise in Kubernetes and cloud infrastructure
• Hands-on Infrastructure as Code experience (e.g. Terraform)
• Strong software engineering background, with production experience in TypeScript and/or Python
• A proven track record of designing and scaling distributed systems in production

Nice to have

• Experience running AI or inference-heavy workloads at scale
• Experience with enterprise security, compliance and data residency
• Direct experience with Azure and Terraform

Process

1. Short intro call with me
2. Technical and experience-based conversation
3. Further steps with the client

Project Overview:

We are looking for an experienced Magento 2 / Adobe Commerce Cloud Developer to join our team and work on the development, customization, integration, and optimization of enterprise-level e-commerce solutions.

The project involves building and maintaining a scalable e-commerce platform, improving performance, implementing new functionality, and integrating third-party services.

Customer Overview:

Our client is a US-based company operating in the fashion and lifestyle e-commerce industry, specializing in premium activewear and athleisure apparel.

The company offers a wide range of fitness and everyday clothing through a direct-to-consumer and independent sales representative business model.

With a strong focus on customer experience, digital commerce, and business growth, the company continuously invests in its e-commerce platform and technology infrastructure.

Responsibilities:

• Develop, customize, and maintain Magento 2 / Adobe Commerce applications.
• Work with Adobe Commerce on Cloud infrastructure (Adobe Commerce Cloud).
• Develop custom modules, extensions, and integrations.
• Integrate third-party systems, including ERP, CRM, payment gateways, and shipping providers.
• Optimize website performance, scalability, and security.
• Develop and maintain REST and GraphQL APIs.
• Troubleshoot technical issues and improve platform stability.
• Participate in code reviews, technical discussions, and architecture decisions.
• Collaborate with frontend developers, QA engineers, DevOps, and project managers.
• Support deployments, upgrades, and ongoing platform maintenance.

Skills/Requirements:

• 3+ years of commercial experience with Magento 2 / Adobe Commerce.
• Strong PHP development skills and experience with object-oriented programming.
• Hands-on experience with Adobe Commerce Cloud.
• Solid knowledge of Magento architecture, modules, plugins, observers, dependency injection, and service contracts.
• Experience with MySQL, Redis, Elasticsearch / OpenSearch.
• Experience developing REST and GraphQL APIs.
• Understanding of Composer, Git, and CI/CD pipelines.
• Experience with cloud deployment, configuration, and environment management.
• Knowledge of Magento performance optimization, caching, and security best practices.
• Strong debugging and problem-solving skills.
• English: Upper-Intermediate or higher.

Keymakr is a leading provider of high-quality data annotation services for machine learning and artificial intelligence applications. We specialize in delivering accurate and scalable annotation solutions that empower businesses to develop cutting-edge AI models. Our team is dedicated to excellence, innovation, and customer satisfaction.

We are looking for a motivated Junior Python Software Engineer to help build, maintain, and improve internal tools and services. This role offers a great opportunity to grow your technical skills while contributing to real-world projects and automation processes.

Technical Skills:

• 2+ years of experience in Software development  
• 1+ years of practical experience with Python.
• Knowledge of RESTful API design and implementation.
• Experience in scripting and automating workflows, including working with APIs for task automation.
• Understanding of software design principles, particularly SOLID.
• Basic knowledge of Linux systems and familiarity with the Linux command line.
• Proficiency with version control systems (e.g., Git, GitHub, Bitbucket).
• Practical experience with web frameworks like Flask, Django, or FastAPI.
• Familiarity with Celery, Redis, and RabbitMQ.
• Hands-on experience with containerization tools like Docker.
• Skilled in writing unit and integration tests.
• Knowledge of cloud platforms (e.g., AWS, Azure, GCP)

Problem-Solving Skills:

• Strong analytical thinking and problem-solving capabilities.
• Ability to debug, troubleshoot, and optimize code effectively.

Nice-to-Have Skills:

• Basic understanding of frontend technologies (HTML, CSS, JavaScript).
• English at an intermediate level or higher (to read and understand technical documentation).
• Familiarity with Agile development methodologies.
• Understanding of CI/CD pipelines and DevOps practices.

Responsibilities:

• Developing and maintaining tools and applications for the company’s infrastructure.
• Designing, supporting, and maintaining internal services.
• Transforming and storing data in various formats (e.g., JSON, XML, CSV).
• Automating workflows using APIs.
• Researching, configuring, and integrating third-party software into company processes.
• Providing general IT support and troubleshooting.

About Us: InnovatelU is a dynamic tech company delivering cutting-edge solutions. We're looking for a passionate Java Developer to join our team. If you have a solid Java foundation, are eager to grow, and learn quickly, we want to hear from you! 

Requirements: 
- Strong knowledge of Java 
- Knowledge of Spring (Spring Core, Spring AOP, Spring MVC, Spring Security, Spring Boot) 
- Familiarity with REST APIs, web services 
- Proficiency in version control tools (Git) 
- Experience with build tools like Maven and Gradle 
- Experience with relational databases (PostgreSQL) 
- Expertise in containerization (Docker) 

- Experience in unit and integration testing 
- Strong communication skills and teamwork ability 
- English level: Intermediate or higher 

Will Be a Plus: 

- Solid understanding of design patterns 

- Experience with NoSQL databases like MongoDB and Redis 

- Familiarity with messaging systems like Kafka and RabbitMQ 

- Experience with microservices architecture 

Responsibilities: 

- Collaborate with senior developers and project managers 

- Assist in designing, coding, and testing applications 

- Write well-designed, efficient, and testable code 

- Participate in code reviews 

- Debug and resolve technical issues 

- Contribute to application documentation 

Interview Stages: 

1. Test Task: 1 hour 

2. HR Interview: 30 minutes 

3. Technical Interview: 1 hour 

We Offer: 

- Full Remote 

- Constant support and mentoring 

- Paid 5 working days of sickness per a year; 

- Paid all official Ukrainian holidays; 

- 18 working days of vacation per a year; 

- Opportunity for professional growth and career development 

If this sounds interesting to you, let's talk!

Description

Our client is an innovative U.S. medical device manufacturer that produces devices and software applications.

The project focuses on the development, maintenance, and enhancement of a healthcare technology platform that supports remote diagnostic testing, patient monitoring, and medical reporting.

The platform enables healthcare providers and diagnostic service organizations to manage diagnostic workflows, including test ordering, patient data collection, result processing, and report generation.

Requirements

## Requirements

– Preferred 5–10 years of experience in backend software engineering, with strong hands-on expertise in Node.js, TypeScript, and NestJS, and a proven track record of delivering high-quality software solutions.
– Strong knowledge of JavaScript (ES6+), TypeScript, Node.js, NestJS, and backend application architecture.
– Experience designing, developing, and maintaining scalable APIs, backend services, and integrations with third-party systems.
– Strong experience with PostgreSQL, TypeORM, Redis, and database design, optimization, and performance troubleshooting.
– Understanding of backend architectural patterns, including CQRS, Event Sourcing, asynchronous processing, and message queues (Bull, AWS SQS/SNS, or similar).
– Ability to analyze, understand, and work with existing complex codebases, including legacy components and limited technical documentation.
– Experience investigating existing system architecture, identifying dependencies, and documenting technical solutions.
– Hands-on experience with AWS services, including Lambda, ECS Fargate, S3, RDS, and CloudFront.
– Understanding of authentication, authorization, and API security principles, including JWT, OAuth 2.0, and Auth0.
– Experience writing unit and integration tests using Jest or similar testing frameworks.
– Experience with Git, Docker, code reviews, CI/CD pipelines, and infrastructure deployment processes.
– Upper-Intermediate English (B2+) or higher.

## Nice to Have

– Experience with serverless architectures, microservices, and real-time communication using WebSockets or Socket.IO.
– Experience developing software solutions in the healthcare or medical technology domain.
– Familiarity with HIPAA, healthcare data privacy, and secure handling of sensitive patient information.
– Experience with Infrastructure as Code (Terraform) and GitHub Actions.
– Exceptional problem-solving and analytical skills, with the ability to investigate complex systems and make informed technical decisions.
– Excellent communication and interpersonal skills, with the ability to collaborate effectively across teams and lead by example.
– A proactive approach to learning, adapting to new technologies, and driving technical improvements.

Job responsibilities

System Discovery & Technical Analysis

– Analyze and understand the existing application, its architecture, codebase, dependencies, and integrations.
– Investigate existing functionality, business logic, and technical workflows to build comprehensive system knowledge.
– Identify technical risks, architectural limitations, legacy components, and areas requiring improvement.
– Create and maintain technical documentation covering application architecture, key components, integrations, and dependencies.
– Participate in knowledge transfer sessions and collaborate with stakeholders to clarify existing system behavior and requirements.

Application Development & Maintenance
– Lead the design and development of robust, high-availability applications, ensuring they align with our architectural vision and business needs.
– Maintain, enhance, and extend existing applications using React Native and TypeScript.
– Design and implement new features based on business and technical requirements.
– Troubleshoot and resolve application defects, performance issues, and production incidents.
– Refactor and improve existing code to increase maintainability, reliability, and scalability.

RedCore is an international business group that creates technological solutions for digital markets. Our products and services cover fintech, marketing, e-commerce, customer service, communications, and regulatory technologies.
 

We are looking for a Team Lead Python to join our team!

Requirements:
- 5+ years of commercial Python development experience.
- 1+ years as a Team Lead.
- Experience with Docker, Kubernetes, CI/CD and cloud environments.
- Understanding REST, experience with different protocols (especially http and gRPC))
- Experience with databases (MongoDB/PostgreSQL/MySQL/Redis) and messaging systems (NATS, Kafka, RabbitMQ or similar).
- Strong engineering practices (code reviews, testing, clean code) and people management skills.

Will be plus:
- Experience with Grafana/LGTM, Datadog or similar observability tools.
- Experience with DORA metrics or engineering performance metrics.
- On-call experience.

Responsibilities:

- Lead a team of backend engineers, providing technical guidance, mentoring and regular feedback.
- Own the team's technical delivery—from planning and estimation to releases and production support.
- Drive code quality, architecture decisions and continuous improvement of existing services.
- Collaborate with Product, QA, DevOps and other stakeholders to ensure predictable delivery.
- Hire, onboard and develop engineers while fostering a culture of ownership and accountability.

Our benefits to you:

- Paid annual leave.

- Paid days off.

- RedCore TEAM corporate gamification system.

- Annual corporate events for employees.

- Reimbursement of business travel expenses.

- Flexible working format and start time.

- Employee learning and development system.

- Mentoring program.

- Overtime compensation.

- Referral program with a cash bonus.

- Corporate psychologist.

- Cafeteria benefit system: sports, insurance, language learning (depends on region).

Overview

An international product-based iGaming company, a B2B game provider with over 12 years of experience in the market, is looking for Senior Backend Engineer (Node.js / TypeScript) – Compliance Engineering to join its Compliance team and build a secure, reliable technical pipeline that supports both game certification and platform compliance.

This is a hands-on engineering role combining backend development, process automation, and technical ownership: you will streamline certification workflows, ensure games and systems are audit-ready and independently represent the technical side of the work to certification labs and external auditors.

Your mission is to help company ship games and platform changes faster and more safely, without compromising compliance standards.

Main Responsibilities

– Own the technical side of game certification, from preparing game math packages and required technical evidence to resolving certification labs’ questions and deficiencies.

– Act as the primary technical point of contact for certification labs, independently explaining technical implementations and providing requested evidence.

– Build and continuously improve a secure compliance pipeline by automating evidence collection, compliance controls, and audit trails, reducing manual work and reliance on undocumented knowledge.

– Support platform compliance activities, including ISO 27001 certification and technical evidence preparation for future SOC 2 audits.

– Represent сompany’s technical processes and systems during external audits, providing clear, accurate, and evidence-based answers to auditors.

– Collaborate with Compliance and Development teams to integrate compliance requirements into development and release workflows, ensuring games and platform changes meet the required standards before release.

Mandatory Requirements

– Strong software engineering background. 3+ years of commercial production development experience. You are a developer first, comfortable navigating unfamiliar codebases, understanding existing implementations, and forming independent technical opinions.

– Strong Node.js and TypeScript. Able to read and verify game math code, understand engine integrations, rules and bets migrations, and build automation tools that ensure the implementation matches what is submitted for certification.

– Experience with certified or regulated products. Ideally, you have worked in an iGaming game provider, lottery or another environment where certification requirements directly influence development, testing, and release processes.

– Automation and pipeline engineering. You can turn manual, high-stakes processes into reliable automated workflows, including evidence collection, version control, audit trails, and release gates.

– Technical and data investigation skills. Comfortable writing SQL queries, investigating logs, and working with metrics and observability tools to identify and verify technical issues.

– Confident external communication and sound judgment. Able to communicate precisely with certification labs and auditors, provide evidence-based answers, stay within your technical authority, and escalate regulatory or commercial matters when needed.

– Ownership, precision, and accountability. You document technical decisions clearly, pay attention to detail, and are comfortable challenging release decisions when requirements are not met, even under delivery pressure.

Nice to have

– Direct experience working with certification labs (GLI, BMM, eCOGRA, iTech Labs, or similar) or gaming regulators.

– Hands-on experience preparing evidence for ISO 27001, SOC 2, or equivalent information-security audits.

– Understanding of RNG, RTP mathematics, and statistical certification evidence.

– Familiarity with multi-jurisdiction licensing (UKGC, MGA, and regulated EU and LatAm markets).

– Experience with observability and alerting tools (Datadog or equivalent), including automation built on top of them.

– Knowledge of change-management controls, audit trails, and segregation-of-duties models.

– Incident response experience, particularly involving regulatory or audit implications

Why join us

– Competitive Salary

– Quarterly Bonuses

– Unlimited Paid Time Off

– Unlimited Paid Sick Leave

– Remote & Flexible Working

– Private Medical Insurance

– Financial Support for Life Events

– Professional Development Budget

– International Exposure

– Regular Company Events

*Benefits may vary depending on location and contractual agreement

Project Description:

The project is focused on improving the security, release reliability, maintainability, and operational resilience of business-critical banking applications.

Forward Deployed Engineers will conduct targeted, hands-on engagements with development teams that are facing challenges with vulnerability remediation, automated testing, legacy technology, production stability, or achieving a safe and rapid release cadence.

The role combines senior software engineering, DevOps, SRE, test automation, application security, and legacy modernization. Approximately 70% of the work involves hands-on coding and configuration.

The technical scope includes building effective automated test suites, remediating security vulnerabilities, performing dependency and reachability analysis, upgrading Java and NPM runtimes, modernizing Spring and legacy middleware applications, improving CI/CD pipelines, containerizing applications, automating deployments, and introducing standard observability and resilience patterns.

The Expert FDE is expected to lead complex engagements, work directly with development and client stakeholders, define the technical remediation approach, implement critical changes personally, and enable client teams to maintain the improved engineering practices.

Responsibilities:

- Lead targeted technical engagements addressing security, testing, release, resilience, and legacy technology challenges with development teams.
- Assess application code, dependencies, runtime environment, test coverage, deployment architecture, CI/CD pipelines, observability, and operational risks.
- Write, debug, review, and enhance production-quality code and configuration throughout engagements.
- Define and implement practical modernization and remediation plans with clear priorities, dependencies, risks, and measurable outcomes.
- Develop or improve unit, integration, component, contract, and deployment smoke tests using Test-Driven Development practices.
- Select appropriate automation-testing approaches per application and drive implementation, including the use of AI coding assistance.
- Source suitable test data and implement secure data masking for lower environments.
- Conduct vulnerability triage, root-cause and dependency reachability analyses, remediation prioritization, secure code changes, and regression testing.
- Upgrade Java, JVM, NPM, Spring, open-source libraries, internal dependencies, installed software, base images, and operating systems to supported versions.
- Establish sustainable dependency-management processes with continuous library updates using Renovate or equivalent tools.
- Modernize legacy applications and middleware stacks, including those deployed on WebSphere or WebLogic.
- Containerize applications using Docker and support deployment to OpenShift.
- Improve source control, branch management, pull-request, and code-review practices.
- Design, implement, and optimize CI/CD pipelines to ensure safe, repeatable, automated, and easy releases.
- Automate database changes using Liquibase or equivalent migration tools.
- Automate installed software and environment changes using Ansible or equivalent configuration management tools.
- Implement secure coding patterns, secrets management, authentication, authorization, and least-privilege controls.
- Introduce standard observability patterns, including structured logging, application metrics, tracing, dashboards, alerting, and actionable health checks.
- Enhance exception handling, operational diagnostics, rollback procedures, and production-validation controls.
- Design or improve resilient deployment architectures, including hot-hot cross-datacenter deployments where required.
- Lead technical workshops and effectively communicate technical decisions, risks, blockers, trade-offs, and progress to engineering, security, architecture, operations, project management, and stakeholders.
- Provide technical leadership through code reviews, coaching, reusable standards, documentation, and knowledge transfer to development teams.
- Take ownership from initial assessment through implementation, production deployment, stabilization, and handover.

Mandatory Skills Description:

The role demands extensive hands-on software engineering experience, with a focus on developing and maintaining production applications. Candidates must actively write and configure code, not merely oversee architecture or management tasks. Expertise in Java and JVM-based development is essential, while strong TypeScript skills are valued for Node.js-centric projects. Proficiency with the Spring ecosystem and modernizing Java enterprise applications is required. The candidate should demonstrate recent personal involvement in coding, debugging, and reviewing production code.

Hard skills include practical experience in Test-Driven Development across multiple testing frameworks, with a solid understanding of various testing types such as unit, integration, and regression tests. The role involves creating automated test suites integrated within CI/CD pipelines, along with designing release automation and quality gates. Strong knowledge of secure coding practices, vulnerability remediation, and dependency risk management is necessary, including the ability to analyze application impacts before applying security fixes. Experience upgrading runtimes, frameworks, libraries, container platforms like Docker or OpenShift, and managing Linux environments—preferably Red Hat Enterprise Linux—is also important. Familiarity with build tools such as Maven, Gradle, or npm, advanced Git workflows, and comprehensive production-debugging techniques is expected. Candidates should understand application observability, exception handling, and production readiness, as well as fundamental distributed and critical system engineering principles.

Soft skills focus on demonstrated ownership of complex technical work through all stages, from design to production handover. Strong client-facing communication is essential, including leading technical discussions, constructively challenging unsafe practices, and explaining trade-offs to diverse stakeholders. The ability to coach engineers and implement sustainable engineering standards without excessive customization is critical. Responsible and active use of AI coding tools to enhance engineering, testing, and delivery outcomes is also expected.

- Hard skills:
  - Java/JVM and optionally TypeScript development with Spring ecosystem expertise
  - Test-Driven Development and automated testing within CI/CD frameworks
  - Secure coding, vulnerability management, and dependency risk analysis
  - Runtime, framework, library upgrades, and container platform management
  - Linux system administration, build tools, Git workflows, and production debugging
  - Application observability and distributed system engineering principles

- Soft skills:
  - End-to-end ownership of technical projects
  - Effective client communication and technical leadership
  - Coaching and sustainable standards implementation
  - Proficient use of AI-assisted development tools

Nice-to-Have Skills Description:

- Experience modernizing or migrating applications hosted on IBM WebSphere or Oracle WebLogic, demonstrating familiarity with these platforms.
- Experience with major-version upgrades and migration from older versions of Spring or Spring Boot, indicating proficiency in framework transitions.
- Experience configuring continuous dependency-update tools such as Renovate or Dependabot, showing capability in automating dependency management.
- Experience with dependency reachability analysis, Software Composition Analysis, CVE assessment, and remediation of transitive dependencies, reflecting knowledge of software security and compliance.
- Experience automating database changes using Liquibase or Flyway, indicating skills in database migration automation.
- Experience using Ansible or equivalent configuration-management and deployment-automation tools, demonstrating proficiency in infrastructure automation.
- Strong experience in TypeScript, Node.js, and the npm ecosystem, highlighting development expertise in these technologies.
- Experience with Kubernetes in addition to OpenShift, showing understanding of container orchestration platforms.
- Experience designing hot-hot, active-active, multi-region, or cross-datacenter deployment architectures, denoting knowledge of high-availability systems.
- Experience with resilience testing, disaster recovery, controlled failover, and production-recovery exercises, highlighting skills in system reliability and continuity planning.
- Experience with enterprise observability tools such as Splunk, ELK, Grafana, Prometheus, OpenTelemetry, AppDynamics, or Dynatrace, reflecting proficiency in monitoring and diagnostics.
- Experience modernizing monolithic or legacy enterprise applications into maintain

Languages:

English: C1 Advanced

Project Description:

You will join a long-term, enterprise-scale project for a global client in the investment banking domain. The project focuses on building and evolving a set of mission-critical backend services that support complex business workflows, regulatory processes, and system integrations across the bank's ecosystem.

The platform is based on a distributed microservices architecture, leveraging Spring Boot, event-driven communication, and BPM-driven process orchestration. The system operates in a cloud-enabled, containerized environment, with a strong emphasis on security, scalability, resiliency, and maintainability.

You will work closely with architects, QA engineers, DevOps, and business stakeholders in an agile setup, contributing not only code but also technical direction, best practices, and mentoring.

Responsibilities:

The Python Engineer's role is to design and implement scalable, production-grade backend systems and microservices. The person we are looking for should be able to develop clean, maintainable codebases, build and scale distributed services, implement well-known communication and integration patterns, and apply best practices for large-scale distributed systems.

Mandatory Skills Description:

• At least 8+ years of practical experience in Python development and delivering production systems.
• Advanced Python proficiency, especially in scalable, clean code architecture and microservices (e.g., FastAPI, AsyncIO)
• Solid understanding of API integration patterns and inter-service communication (e.g., REST, Kafka)
• At least two backend/data-intensive solutions successfully delivered to production, ideally involving high-throughput APIs, data pipelines, or search/retrieval systems
• Practical knowledge and hands-on experience with: Relational and NoSQL databases (e.g., PostgreSQL, MongoDB), caching layers (e.g., Redis), message queues, and containerization (Docker, Kubernetes)
• Strong grasp of software engineering fundamentals: data structures, algorithms, concurrency, asynchronous programming, and API design (REST/gRPC)
• Solid understanding of testing practices: unit, integration, and end-to-end testing (e.g., pytest), plus CI/CD pipelines
• Ability to evaluate trade-offs and select appropriate tools, frameworks, and architectural patterns for a given problem
• Experience with PoC development and iterating quickly based on results
• Familiarity with cloud platforms (e.g., Azure, AWS, GCP) and infrastructure-as-code
• Strong debugging, profiling, and optimization skills for high-performance Python applications

Nice-to-Have Skills Description:

• Familiarity with agentic frameworks such as LangChain/LangGraph, LlamaIndex, or similar
• Practical experience integrating LLMs (e.g., OpenAI, Anthropic) into production applications, including prompt engineering and tool/function calling
• Knowledge of RAG architectures, embeddings (e.g., OpenAI), and vector databases (e.g., FAISS, Azure AI Search)
• Awareness of LLM evaluation, guardrails, and cost/latency trade-offs when designing AI-powered services

Languages:

English: B2 Upper Intermediate

On behalf of our Client from Japan, Mobilunity is looking for a Scala Engineer.

Our client is a fast-growing fintech company based in Tokyo that offers its real-time monthly consolidated credit service all across Japan. Our client started Japan’s first instant post-pay credit service for e-commerce customers in October 2014. The main product is an online payment platform which requires no pre-registration or credit card to use; via this service the customers can purchase products online using only a mobile phone number and email address and settle a single monthly bill for all their purchases, either at a convenience store, by bank transfer or auto debit. Customers can use credit funds during a month and then return the balance to zero without paying credit interests.

This service also supports multi-pay installments and subscriptions. There are currently over 4 million accounts in use. This service got the largest investment to date in the Japanese financial tech industry, including PayPal Ventures investment.

Key Responsibilities:

You will be responsible for developing and scaling their payments platform while meeting the highest standards in terms of security, maintainability and resilience to failure. You will meet regularly with the product team to align software delivery with business goals. With the help of your team members, you will come up with software design tradeoffs and communicate them clearly to other engineers as well as product team members to implement mutually agreed-upon solutions. You will also have the opportunity to work cross functionally in feature teams to deliver product features and services. In addition to regular deliverables expected of the engineering team, you are expected to follow and stay current with industry best practices such as writing automated tests and taking part in regular code reviews to ensure quality code at its highest possible standards.

Requirements:

• Solid experience with Scala, Functional Programming and the Typelevel ecosystem
• Experience with Akka Cluster, Cats, Cassandra, Redis, Elasticsearch, Kafka
• Understanding of software architecture and design with the ability to align the overall service architecture
• Experience with building distributed systems, scalability and high throughput software
• Experience with maintaining and further developing existing code bases
• Comfortable with knowledge sharing, working on a team and building relationships
• Ability to define task outlines and deliverables, demonstrate a sense of urgency when required and manage some ambiguity and exercises good judgment when needed
• Ability to give and receive constructive feedback tactfully upstream and downstream
• Excellent communication skills, ability to interact effectively with multidisciplinary teams
• Level of English – Upper-Intermediate and higher

Nice to have:

• Experience with Event Sourcing and CQRS
• Understanding of JVM internals and performance optimization
• Experience with CircleCI, AWS, Fargate, Terraform, Datadog
• Experience working on a payment platform or other fintech field

In return we offer:

• The friendliest community of like-minded IT-people
• Open knowledge-sharing environment – exclusive access to a rich pool of colleagues willing to share their endless insights into the broadest variety of modern technologies
• Paid vacations and sick leaves, including 5 paid days per year that don’t require a sick note
• English classes in 1-to-1 & group modes with elements of gamification
• Neverending fun: sports events, tournaments, music band, multiple affinity groups

Come on board, and let’s grow together!

Cropwise Operations is a global leader in digital agritech solutions, operating in over 50 countries and helping optimize business processes and improve the efficiency of agronomic decision-making.  

We are looking for a skilled Ruby on Rails Developer to join our team.

What we expect from a candidate:

- Preferably 3+ years of Ruby on Rails development experience.

- Strong knowledge of Rails.

- Experience with testing frameworks like RSpec and Capybara.

- Testing with RSpec/Capybara.

- Basic knowledge of ES6 + React.js.

- Experience with JavaScript.

- Standard Rails application deployment stack (Git, CI, Capistrano, *nix).

- Knowledge of HTML/CSS.

What exactly will you need to work with:

- Backend on Ruby on Rails 7.0 (Ruby 3.2).

- PostgreSQL + PostGIS database (handling large geospatial datasets).

- Job processing with Resque + Redis.

- Testing on RSpec + Capybara + CI.

- Partially frontend on React.js (ES6, JSX).

What else can you work with?

- Algorithms for processing large amounts of geodata.

- Reception and processing of binary data (Ruby eventmachine).

- Working with RabbitMQ.

- AWS, Google Cloud, Kubernetes.

- Visualization and work with geodata on the frontend (Mapbox GL JS).

Hiring process:

- Intro call;

- Test Task;

- Final Interview;

- Offer.

The company offers:

- Opportunity to be a part of a best-in-class product that is used by thousands of companies around the world.

- Participation in complex technical tasks and challenges.

- Environment where you need to seek and implement unique engineering and technical solutions.

- Trainings and development programs.

- Flexible work formats: remote, office or hybrid.

- Health and life insurance for employees and your family members.

- 32 working days of paid annual leave and sick leave.

About Cropwise Operations

Cropwise Operations is a SaaS platform for farmers, leveraging cutting-edge technologies such as computer vision, big data, and AI to deliver actionable insights and improve agricultural outcomes.

For seekers, cooperation with Cropwise Operations is an opportunity to be part of a best-in-class product used by hundreds of companies around the world, and to deal with complex technical tasks in the field of neural networks and machine learning with the need to constantly improve their knowledge and skills, to find and implement unique engineering and technical solutions.

The Mission

Wallee Group is a leader in advanced payment solutions, dedicated to providing robust, scalable, and secure systems across multiple domains. We enhance customer experiences through innovative payment and finance technology that empowers businesses to grow efficiently. With operations spanning several countries, we thrive on collaboration and agility, utilizing the Scrum framework to drive our international teams. At Wallee, we stay at the forefront of market trends, continuously innovating to deliver premier services to our global customers.

The Role

To achieve our mission of providing the market's best payment experience, Wallee is seeking experienced and versatile java software engineers. As disruptors in the payment space, we build industry-leading systems that demand the highest standards of security and reliability. We are constantly pushing our solutions into new territories, and we are looking for engineers who thrive in a fast-paced, agile environment to help us redefine the future of finance.

Tasks

Your Impact

• Architect Scalability: Design and develop highly resilient back-end systems using Java, ensuring our infrastructure handles global scale with ease.
• Feature Innovation: Own the end-to-end lifecycle of new features, from initial implementation to refined bug fixing and performance tuning.
• Collaborative Engineering: Work closely with product managers, UX designers, and QA to translate complex business needs into elegant technical solutions.
• Code Excellence: Drive quality through automated testing, rigorous code reviews, and the creation of clear, maintainable technical documentation.
• Stay Ahead: Continuously research and evaluate emerging technologies and methodologies to keep Wallee at the cutting edge of the fintech industry.

Requirements

What You Bring to the Table

• Technical Depth: Advanced proficiency in Java and core frameworks such as Spring, Spring Boot, and Hibernate.
• Systems Thinking: Proven experience building distributed systems and scalable, high-availability solutions.
• Data Mastery: Strong proficiency in SQL and experience managing complex data structures.
• Modern DevOps: Hands-on experience with CI/CD pipelines (Jenkins/GitLab CI) and containerization (Docker, AWS ECS).
• Agile Mindset: A degree in Computer Science (or equivalent experience) and a track record of thriving in fast-paced, Agile environments.

• Bonus Points: Experience with JavaScript, Apache Camel, or BPM engines.

   

  Benefits:

• You are part of an agile, young international team and shape our products sustainably with your ideas.
• You will play a decisive role in designing products in an omni channel payment start-up and work with leading companies in the financial industry on international projects.
• We offer flexible structures and flat hierarchies.
• Cooperation with motivated colleagues and numerous personal development opportunities.

Responsibilities

• Maintain and extend existing functionality in a large legacy PHP 7.4 codebase.
• Design and implement robust solutions for bug fixes, new features, and technical debt reduction.
• Optimize database queries and schema design using PostgreSQL.
• Refactor old modules and participate in gradual modernization plans.
• Collaborate with DevOps and QA to ensure system stability and deployment continuity.
• Participate in technical discussions, code reviews, and architecture planning.
• Work closely with cross-functional teams including product managers and front-end developers.

Requirements

• 5+ years of experience with PHP, including work with legacy systems (ideally PHP 7.x).
• Strong proficiency with PostgreSQL or similar relational databases.
• Deep understanding of object-oriented programming, software design patterns, and MVC architecture.
• Experience with RESTful APIs and integration of third-party services.
• Version control with Git.
• Strong debugging and performance profiling skills.

As A Plus

• Knowledge of Python for scripting or integration purposes.
• Experience working with SOAP web services and legacy protocols.
• Familiarity with WebSockets and TCP socket-level communication.
• Exposure to systems migration, re-architecture, or code modernization projects.

We Offer

• Competitive salary
• Flexible schedule
• Social package
• Courses, webinars, and seminars to increase professional skills
• Possibility to work remotely and onsite
• Horizontal hierarchy. No micromanagement pressure
• Open company culture where your ideas and initiatives are valued
• Regular team building & corporate events
• International projects

We're looking for a mid-senior Backend Engineer with strong Go and PostgreSQL skills. You'll join an early-stage, venture-backed startup as one of its first backend hires. The company is building a TikTok-style endless scroll of user-generated hypercasual mini-games. Your job is to build the core services behind the game feed, user data and content delivery, and to shape the product's technical direction for years to come. This is a founding-level role with real ownership, for someone who wants to build from the ground up and not maintain someone else's system.

Details: 

• Location: Sofia, Bulgaria, on-site 5 days a week
• Employment: Full-time (no contractor, consultant or B2B setups)
• Level: Mid-Senior
• Relocation: Supported for strong candidates (1–1.5 months' notice maximum)

What you'll do

• Design and build the Go services that power the game feed, user data and content delivery
• Own PostgreSQL schema design and query performance as the product scales
• Own deployments and keep services reliable (Linux, Docker)
• Set up observability (logging, metrics, tracing) from day one
• Work on data pipelines and recommendation / feed-ranking logic
• Design REST APIs for iOS and Android clients
• Work closely with the founders on technical and product direction

Tech stack

Go, Fiber, PostgreSQL, Docker, Linux, REST APIs, data pipelines, recommendation systems

Requirements

• 3+ years of production Go experience, having shipped and maintained services under real traffic
• Solid PostgreSQL experience beyond basic CRUD, including schema design and query optimisation
• Hands-on experience with Linux and Docker, including owning deployments
• Based in Sofia or willing to relocate there
• Ready for full-time, 5-day on-site work

Nice to have

• Experience with recommendation systems, feed ranking or ML-adjacent data pipelines
• Background in hyper-casual gaming or rapid-prototyping environments
• Experience designing APIs for mobile clients
• A startup or founder-led mindset, comfortable with speed and ambiguity

Hiring process

1. Online interview to discuss your experience and mutual fit
2. In-person technical challenge and interview at the Sofia office