Jobs Backend

Numerical Technologies LTD is a leading provider of custom software solutions and services specializing in risk, limits, and regulatory capital systems. We are currently looking for a Senior Python Developer to join our team.

Project: Development of a Market Risk platform for a global financial institution, supporting risk analytics, market data processing, and large-scale financial applications. 

What will you be doing?
You will design and build risk calculations for Hypothetical P&L, Risk-Theoretical P&L, and Historical VaR — owning the full HVaR pipeline end-to-end, and architecting calculation components for the upcoming Expected Shortfall extension. Along the way, you will optimise compute-intensive batch and intraday workloads, own quality through automated testing and reconciliation frameworks, and collaborate closely with quant developers and the Historical Data Store team.

What are we looking for?

• Programming: Expert-level in at least one of Python, C++, or Java/Scala, with strong Python regardless (the analytics ecosystem is Python-centric).
• Distributed/large-scale compute: Experience building or operating high-throughput calculation platforms — grid computing, Spark/Dask/Ray, or in-house distributed batch frameworks; profiling and optimising numerical workloads.
• Risk domain: Working knowledge of market risk measures — VaR (historical simulation in particular), P&L vectors, scenario shocks (absolute/relative/log returns), aggregation and netting.
• Data engineering fundamentals: Handling large time-series and position datasets efficiently (columnar formats, partitioning, memory management).
• Engineering practice: CI/CD, automated testing of numerical code (tolerance-based comparison, golden datasets), code review culture.

Nice to have: 

• Experience with HPL/RTPL production and PLA testing.
• Numerical computing depth: numpy/scipy internals, vectorisation, GPU acceleration.
• Experience integrating with quant pricing libraries via C++/Python bindings.

What we offer:

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

The Defense Procurement Agency (DOT) is a state-owned enterprise responsible for procuring military equipment, ammunition, UAVs, fuel, food, clothing, and other critical supplies for the Armed Forces of Ukraine and the Defense Forces.

Our mission: Strengthening Ukraine's defense capabilities by ensuring reliable procurement and supporting the development of the national defense industry.

Our vision: To become the driving force behind a modern defense procurement ecosystem built according to NATO standards.

We are looking for an ERP Developer (.NET) to help develop, maintain, and enhance our corporate ERP platform, automate business processes, build system integrations, and ensure the stable operation of mission-critical enterprise services.

Responsibilities

• Develop, maintain, and improve the corporate ERP system according to business needs.
• Analyze business requirements and participate in solution design and technical implementation.
• Configure and support business processes, workflows, documents, directories, reports, and approval routes.
• Develop and maintain integrations with internal and external systems using APIs, databases, file exchange, and other integration mechanisms.
• Work with relational databases, write and optimize SQL queries, validate data integrity, and troubleshoot data issues.
• Participate in testing, release management, incident investigation, bug fixing, and production support.
• Create and maintain technical documentation for implemented features, integrations, configurations, and data processing logic.

Requirements

• Bachelor's degree in Computer Science, Information Technology, or a related field.
• 2+ years of experience working with ERP or enterprise information systems.
• Experience analyzing business requirements and configuring business processes, workflows, documents, reports, or approval routes.
• Strong SQL skills and hands-on experience with relational databases.
• Understanding of system integration principles and experience with APIs or other data exchange mechanisms.
• Basic knowledge of C#/.NET or another backend technology is a plus.
• Experience with testing, troubleshooting, and technical documentation.
• Strong analytical and problem-solving skills.
• Attention to detail and commitment to system reliability and software quality.
• Willingness to work with both new development and legacy systems.
• Strong communication skills and ability to collaborate with technical teams and business stakeholders.
• Ability to work independently and take ownership of assigned tasks.
• Zero tolerance for corruption.

Nice to Have

• Hands-on experience with IT-Enterprise ERP.
• Experience developing or supporting IT-Enterprise modules.
• Experience automating document management and approval workflows.
• Experience with procurement, finance, warehouse, inventory, or accounting processes.
• Experience working in government institutions or large enterprise environments.

What We Offer

• Work that directly contributes to strengthening Ukraine's defense capabilities.
• Official employment with competitive salary and full social benefits.
• Professional development, learning opportunities, and career growth.
• Structured onboarding and dedicated mentorship.
• A collaborative, supportive, and mission-driven team.
• Modern office near the metro with reliable internet and equipped shelter.
• Opportunity to work on large-scale enterprise systems with real national impact.

By joining our team, you will contribute to one of Ukraine's largest digital transformation initiatives in the defense sector and help build the future of defense procurement.

Ready to make a real impact? We'd love to hear from you. Apply today!

* By submitting your CV, you consent to the processing of your personal data in accordance with applicable legislation.

** Due to the high volume of applications, only candidates whose qualifications best match the position will be contacted.

Come Back Agency supports US software and technology companies by running their hiring process. We work with delivery and leadership teams to define roles, screen candidates, and manage interviews. Successful candidates are hired directly by the company and become part of its team. This position is with a US-based software company providing custom development and AI implementation for North American clients. The team builds and maintains production software, including AI-enabled systems, and works in long-term client engagements.

Team members operate as part of an internal, distributed team and collaborate directly with client stakeholders.

What we’re looking for:

• Proven experience as a WordPress Developer, with a portfolio of previous projects.
• Proficiency in WordPress theme and plugin development.
• Strong knowledge of PHP, HTML, CSS, and JavaScript.
• Familiarity with responsive design principles.
• Experience working with MySQL or other relational databases.
• Understanding of web standards and optimization techniques.
• Good English communication skills (B1+ level).
• Ability to work collaboratively in a team environment.
• Excellent problem-solving and debugging skills.
• Strong attention to detail and the ability to meet project deadlines.

What you’ll be doing:

• Collaborate with design and development teams to create and maintain WordPress websites and applications.
• Customize WordPress themes and plugins to meet client requirements.
• Develop custom functionalities and features using PHP, HTML, CSS, and JavaScript.
• Ensure the security, performance, and scalability of WordPress sites.
• Troubleshoot and debug WordPress-related issues.
• Stay up to date with the latest industry trends and best practices in WordPress development.

What We Offer:

• Working hours aligned with US time zones, typically 16:00—00:00 Kyiv time.
• English lessons to support clear and confident communication.
• Paid vacation and sick days.
• Fully remote work.
• Opportunities for professional growth within the team.
• Structured, personalized onboarding to help you ramp up effectively.

Hiring stages: Recruiter screening → Test assignment → Skills assessment interview.

Apply with your resume and a short note outlining your relevant experience. You can also send your resume directly using our website at comeback.ua. Selected candidates will be contacted by Come Back Agency.

This role is more focused on backend development with Node.js and TypeScript, but it also requires React experience so you can handle your frontend tasks independently rather than relying on a frontend developer.

Infrastructure and production environments are handled by a separate DevOps team, so your focus will remain on application development rather than production support or infrastructure management.

Responsibilities

1. Design, develop, and maintain backend services throughout the full development lifecycle
2. Assist with frontend implementation when needed to deliver product features
3. Release new functionality and monitor feature stability after deployment
4. Work closely with Product, Platform, and Reliability teams
5. Contribute to technical improvements and enhancements within the existing architecture

Tech Stack

Node.js, TypeScript, React, Redis, MySQL, PostgreSQL, Elasticsearch, Kafka/RabbitMQ, monitoring and observability tools

Requirements

• Strong hands-on commercial experience with Node.js and TypeScript
• Experience with React and modern frontend engineering practices
• Solid experience with databases, caching, and data management approaches
• Experience investigating and resolving issues in distributed environments
• A product ownership mindset, with the ability to take features from concept to production
• English communication skills for daily collaboration and team meetings

Nice to Have

Experience with microservice architectures and API development

Experience with Docker and Kubernetes

Knowledge of application performance tuning and optimization

Basic understanding of Linux and networking

Familiarity with clean architecture principles and testing methodologies

What the Company Offers

• Fully remote work environment with a flexible schedule
• Paid vacation and days off
• Salary reviews twice a year
• B2B/contractor cooperation model with accounting support
• An opportunity to work on a large-scale product and influence technical direction

We are looking for a Junior-Middle Backend Developer to join a fast-growing start-up developing a product for automated lead generation and recruitment outreach.

Responsibilities:

• Day-to-day product implementation.
• Develop integrations with AI (e.g., Perplexity, OpenAI) & 3rd party API (e.g., CRMs).
• Leverage your prompt engineering skills to maximize the outcome.
• Customer discovery. That includes: internal product conversations, as well as joining some customer calls (Maybe not from day one, but definitely later on).

Requirements:

• At least 1 year of experience working in a product company/startup.
• 1-3 years of software development experience.
• Experience with Node.js, TypeScript, JSON, REST API, Git.
• Experience in LLM/RAG, MCP, and AI agent development and prompt engineering.
• Database design and optimization (SQL).
• Development in cloud infrastructure (AWS/GCP/Azure).
• Patterns for asynchronous task processing (RabbitMQ, SQS, or similar).
• Experience with n8n/make will be a great plus.
• Excellent verbal communication skills.
• Excellent English, minimum B2 level.
• Absolutely customer-centric and flexible in a dynamic environment (i.e., fully tolerant of shifting priorities daily).

Job details:

• Full-time.
• Fully remote.
• Long-term.
• B2B contract.
• Start date — ideally ASAP, but negotiable.

What else will you get:

• Learning how a startup grows.
• Direct impact on product and company strategy.
• Deliver value directly to paying B2B clients.
• You will work with the most modern toolset (including Cursor in Agent mode).

The hiring process:

• 30-45 min pre-screen interview with a recruitment manager.
• 30 min call with the client.
• A technical deep-dive interview, most likely with online coding (conducted by the client).

We are looking for an AI-First Golang Team Lead for one of our product engineering pods: a hands-on engineer who uses AI to ship fast and acts as the face of their pod towards clients and leadership.

⚠️IMPORTANT: This is not a traditional coding role. You’ll use Claude Code and other AI tools to 10x your output, always thinking about how the product or feature you are working on benefits the user. Also: we have no QA team, you OWN the quality of what you ship!

🧭About this role: every engineer on the team already owns their work end-to-end (IC + DRI). Everyone in the pod is, in effect, their own architect and lead developer. So this role is not about being the strongest techie in the room or telling people how to build.

A Team Lead is the spokesperson, coordinator, and facilitator for their pod, internally with product, design, and leadership, and externally with clients. You come from the management path, not the deep-specialist path: you have seen a lot as a developer and have consciously decided that enabling a team, working with clients and driving product outcomes is what energizes you now, not coding all day.

You remain a hands-on engineer. Expect roughly 30-40% of your week on coordination, client and product work, and the rest as an individual contributor. This is not an HR-style people-management role: no performance reviews, no career coaching. As we scale, light one-on-ones and check-ins may become part of it, but the job is coordination and delivery, not administration.

🧑 💻 What you’ll actually do:

• Be the spokesperson for your pod, internally with product, design, and leadership, and externally with clients and partners.
• Coordinate work across the pod: break initiatives into chunks, sequence them, surface blockers, and facilitate hand-offs (lightweight project management; we deliberately have no project managers).
• Gather client requirements first-hand and funnel them straight into the pod so nothing gets lost in translation.
• Represent your pod in product planning sessions and bring a strong product-driven point of view to scoping and trade-offs.
• Help pod members with product decisions and prioritization, enabling engineers who may be technically stronger than you.
• Contribute hands-on as an engineer: own features end-to-end, use Claude Code to generate Golang backend code, review AI output for quality and architectural fit.
• Join client meetings to align on requirements, report on delivery, and keep the relationship professional and calm.

📚 Our stack:

• Backend: Go monorepo (no framework, 3+ services).
• Hosting: PaaS-managed containers; local setup fully mirrors production via Docker Compose.
• Tools: Jaeger tracing, Betterstack (Logging, Alerting), Redis Asynq queue.
• Databases: PostgreSQL, Redis.
• AI tooling: Claude Code (mandatory).

🚢 Products you will lead a pod on:

• An AI search & recommendation engine for major travel enterprises: heavy client integration work (SSO, security reviews, GDS integrations) with demanding enterprise customers.
• A content enrichment API: high-scale, data- and AI-focused backend work.
• Partner and supplier integrations, data ingestion pipelines, LLM providers.

✅ You must have:

• 2-3+ years of technical leadership experience leading a team, squad, pod, or similar unit (a hard must; think team lead or early-stage engineering manager).
• A developer’s background (minimum 5 years): you have seen production reality with your own hands before moving towards leading people.
• A genuinely product-driven mindset: you think about user value and business outcomes before implementation.
• Comfort facilitating and coordinating a pod without relying on formal authority.
• Willingness and ability to take part in client meetings and act as the external face of your pod.
• Excellent spoken and written English for planning sessions, stakeholder updates, and client conversations.
• Ownership mentality with a strive for elegantly simple, high-quality solutions; you test your own work thoroughly since we have no QA team.
• Proven experience using Claude Code; share specific examples.
• Solid Golang experience; you’ll review AI’s code, and you must understand how it works.
• Ability to do on-call once in a while to help maintain our platform’s reliability & uptime.
• ⚠️ European or African timezones (±3 hours from CET).
• Available full-time (40 hours/week).

❤️ You are a great fit if you:

• Made the classic developer’s fork-in-the-road decision: lifelong engineer or leading people, and chose people, clients, and product.
• Are energized by product planning sessions and have opinions about what the pod should build next, not just how.
• Are comfortable being the face of your pod, in internal planning rooms and on calls with enterprise clients.
• Enjoy enabling engineers who are technically stronger than you.
• Ship fast but always verify it actually works; think “how can AI build this?” as your first instinct.
• Get frustrated when development takes weeks instead of days.

‼️Things to consider before applying that won’t be a match:

• This would be your first leadership role.
• You see the lead as the chief architect who makes the technical decisions for the team.
• You are looking for an HR-focused people-management role built around performance reviews and career coaching.
• You want to lead a team without staying hands-on in the codebase.
• You would rather not take part in client meetings or stakeholder-facing conversations.
• You prefer to focus on execution and leave product planning to others.
• You rely on formal authority to get a team moving.
• You have never used Claude Code or similar AI coding tools.
• You are outside European/African timezones.

ZentixSoft is looking for a Senior Backend Developer – Tech Lead! 🚀

Format: Full-Time Outstaffing, long-term remote engagement. 
 

💡 Why ZentixSoft?

💸 Salary Review: A structured system of compensation reviews aligned with your engineering growth.

⚖️ Work-Life Balance: Sustainable workflows with no senseless overtime, helping you keep your resource fully charged.

🦾 Trust and Transparency: Zero micromanagement and no invasive time-trackers—we fully trust your professional autonomy.

🎁 Gifts & Culture: Corporate gifts for holidays, birthdays, and a true team atmosphere where your voice always matters.
 

🧩 Responsibilities:

• Architecture & Development: Architect, design, develop, and support high-performance business applications using C# and modern .NET ecosystems.
• Technical Leadership & Mentorship: Serve as the driving force behind backend activities, mentoring developers and raising code quality across the team.
• API & Integration Design: Build and consume high-speed RESTful APIs with advanced rate-limiting, caching, and queuing mechanisms.
• Messaging & Microservices: Implement messaging communication patterns using message brokers (RabbitMQ, Kafka, or Azure Service Bus).
• Engineering Standards: Adopt best practices in software design patterns, CI/CD, unit/integration testing, structured logging, and authorization security.
   

🎓 Our Perfect Match (Requirements):

• Backend Expertise: 6+ years of commercial backend development experience with C# and .NET frameworks.
• Databases: Strong SQL skills with relational databases (preferably PostgreSQL or MySQL).
• Messaging & APIs: Hands-on experience with messaging systems (RabbitMQ, Kafka, or Azure Service Bus) and advanced API design.
• Software Architecture: Deep knowledge of modern design patterns, microservices architectures, MVC, and software design principles.
• Testing & Tools: Experience with unit and integration testing, Git workflows (GitHub), structured logging, and authorization/security standards.
• Frontend Fundamentals: Working knowledge of basic web technologies (HTML, CSS, JavaScript, HTTP protocols).
• Soft Skills & Communication: Strong written and verbal English skills, team orientation, and a proactive, solution-minded attitude.
   

➕ Nice to Have:

• Experience with Blazor, gRPC, or Angular (reactive programming).
• Experience with TDD (Test-Driven Development) and Scrum/Agile methodologies.
   

📍 Project Details:

⏳ Duration: Long-term (Full-time).

📍 Location: Fully Remote.

Digis is an international technology company, part of Fiverr (NYSE: FVRR), with 250+ specialists delivering high-load SaaS platforms, enterprise solutions, and cloud-native products for clients worldwide. We build long-term engineering teams and ensure transparency, stability, and professional growth for every talent.

About the Project

Large SaaS platform in the e-commerce domain that automates store operations for online sellers. The platform covers product importing, inventory and price synchronization, supplier integrations, order fulfillment automation, and marketplace management.

Hybrid work model: 3 days per week in the Warsaw office

Responsibilities:

• Create new landing pages and test paid vs. free funnel models
• Integrate payment flows, including Stripe, into new funnel experiences
• Develop and test alternative versions of existing flows for A/B testing
• Integrate with Shopify and other external APIs used in the funnel
• Support and extend the existing WordPress/PHP-based funnel when needed
• Gradually migrate parts of the existing solution toward React and newer architecture

Requirements:

• 5+ years of general software development experience
• 3+ years of hands-on experience with Wordpress
• 1+ year of hands-on experience with ReactJS
• English level: Upper-Intermediate or higher

We offer:

• Competitive compensation package
• Long-term cooperation and stability
• Proven product with around 10 years of successful operation
• Strong company backing as part of the Fiverr Group
• New team built from scratch with room to shape its ways of working
• Bi-weekly engineering discussions on architecture, implementation, and knowledge sharing
• AI-powered development supported by the client, including Claude Code for coding, refactoring, PR reviews, and Jira/Confluence tasks

If this sounds like the right opportunity for you, apply now!

When applying, please confirm that you are able to work in a hybrid format and visit our Warsaw office 3 times per week.

Short overview of the project (What technology stack is used on the project, and length of the project)

AI tourism platform looking for a Team Lead Product Engineer who uses AI to ship fast.

📚 Our stack:

Backend: Go monorepo (no framework, 3+ services)

Hosting: PaaS-managed containers, local setup fully mirrors production via Docker Compose

Tools: Jaeger tracing, Betterstack (Logging, Alerting), Redis Asynq queue

Databases: PostgreSQL, Redis

AI tooling: Claude Code (mandatory)

🚢 Products you will lead a pod on:

An AI search & recommendation engine for major travel enterprises: heavy client integration work (SSO, security reviews, GDS integrations) with demanding enterprise customers

A content enrichment API: high-scale, data- and AI-focused backend work

Partner and supplier integrations, data ingestion pipelines, LLM providers

Employment and number of hours per week/month (part-time, full-time, freelance)

Engagement: full-time, 40 hours/week

Candidate’s location and required Time Zone for work

Location: remote, within ±3 hours of CET

Timezone is the main priority, so your usual scope of EU and Ukraine within the required overlap works well. 

Language of communication

Language: English required

Functional responsibilities (What will an employee do on the project?)

⚠️ European or African timezones (±3 hours from CET) Available full-time (40 hours/week)

⚠️IMPORTANT: This is not a traditional coding role. You'll use Claude Code and other AI tools to 10x your output, always thinking about how the product or feature you are working on benefits the user. Also: we have no QA team, you OWN the quality of what you ship!

A Team Lead is the spokesperson, coordinator and facilitator for their pod, internally with product, design and leadership, and externally with clients. You come from the management path, not the deep-specialist path: you have seen a lot as a developer and have consciously decided that enabling a team, working with clients and driving product outcomes is what energises you now, not coding all day.

You remain a hands-on engineer. Expect roughly 30-40% of your week on coordination, client and product work, and the rest as an individual contributor. This is not an HR-style people-management role: no performance reviews, no career coaching. As we scale, light one-on-ones and check-ins may become part of it, but the job is coordination and delivery, not administration.

What you'll actually do:

Be the spokesperson for your pod, internally with product, design and leadership, and externally with clients and partners

Coordinate work across the pod: break initiatives into chunks, sequence them, surface blockers and facilitate hand-offs (lightweight project management, we deliberately have no project managers)

Gather client requirements first-hand and funnel them straight into the pod so nothing gets lost in translation

Represent your pod in product planning sessions and bring a strong product-driven point of view to scoping and trade-offs

Help pod members with product decisions and prioritisation, enabling engineers who may be technically stronger than you

Contribute hands-on as an engineer: own features end-to-end, use Claude Code to generate Golang backend code, review AI output for quality and architectural fit

Join client meetings to align on requirements, report on delivery and keep the relationship professional and calm

Requirements for a candidate

Min 5 years of experience

2-3+ years of technical leadership experience leading a team, squad, pod or similar unit (a hard must, think team lead or early-stage engineering manager)

A developer's background (5 years minimum): you have seen production reality with your own hands before moving towards leading people

A genuinely product-driven mindset: you think about user value and business outcomes before implementation

Comfort facilitating and coordinating a pod without relying on formal authority

Willingness and ability to take part in client meetings and act as the external face of your pod

Excellent spoken and written English for planning sessions, stakeholder updates and client conversations

Ownership mentality with a strive for elegantly simple, high-quality solutions; you test your own work thoroughly since we have no QA team

Proven experience using Claude Code, share specific examples

Solid Golang experience, you'll review AI's code and you must understand how it works

Ability to do on-call once in a while to help maintain our platform's reliability & uptime

Must-Have Requirements (Team Lead — no flexibility on any)

Go (Golang): Real production experience, not just personal projects. No flexibility on other technologies.

AI/backend engineering: Deep knowledge of building and productionizing complex AI systems — observability, reliability, quality

Product mindset: Ability to think beyond engineering toward product outcomes

Leadership: Capable of leading without needing coaching or internal mentoring

English communication: Very strong, given client-facing responsibilities

Minimum 5 years of experience across the board

Candidates should be responsible for testing their own code — QA ownership expected

The Team Lead will head a small pod (not a traditional manager with direct reports)

Client-facing responsibilities begin from onboarding, with full client-facing ownership expected to grow over time

Also they will have on-call duties (now it’s during working hours and weekends, rotation among team members, but later they want to have 24/7 on call, so one person will be on-call for 24 hours (probably) and it will be compensated extra). 

Nice-to-Have

German language: A significant bonus but not required — the one criteria the client can flex on

Any special requirements for the person 

❤️ You are a great fit if you:

Made the classic developer's fork-in-the-road decision, lifelong engineer or leading people, and chose people, clients and product

Are energised by product planning sessions and have opinions about what the pod should build next, not just how

Are comfortable being the face of your pod, in internal planning rooms and on calls with enterprise clients

Enjoy enabling engineers who are technically stronger than you

We invite you, a highly motivated and results-oriented Rust Engineer, to join our team full-time for ensuring solutions, as well as strengthening the product.
 

Our team has unique expertise in research, analysis, and product development. By relying on technical insights and a data-driven approach, we create disruptive future-defining innovations of the fin-tech industry that remain our basis for success.
 

Responsibilities

• Contribute to design the full architecture of the core platform and its supporting systems
• Make key technical decisions on the technology stack, infrastructure, and overall system design with minimal oversight
• Build the initial production-ready implementation
• Cross-functional collaboration with other teams and across the technology stack
• Contributing to the development of the product core

Requirements

• 3+ years of commercial Rust development experience
• 5+ years of systems development experience
• Understanding of the trading domain and its underlying processes
• Deep knowledge of async Rust: tokio/async-std, futures
• Strong systems programming background: memory management, concurrency, low-level optimization
• Solid understanding of network protocols: TCP/UDP, WebSocket
• Experience with in-memory data stores (Redis) or equivalent data stores
• Familiarity with distributed systems design principles
• Experience with AI assist agentic coding tools (Claude Code, Codex, etc.)
• Strong Intermediate level of English

Nice to have

• Strong data modeling skills and schema design
• Basic of understanding quantitative trading

We offer

• 20 paid vacation days per year
• 10 paid sick leave days per year
• Public holidays as per the company’s approved Public holiday list
• Medical insurance
• Opportunity to work remotely
• Professional education budget
• Language learning budget
• Wellness budget (gym membership, sports gear and related expenses)

You will own the integrations between commerce platforms (Shopify, POS, OMS, third-party SaaS) and the data that moves through them for a large replatforming program. The standard is data correctness at the systems-of-record level: orders, inventory and fulfillment must agree across every platform, provably, before and after cutover. This is a long-term, full-time engagement. It is backend integration engineering, not storefront or theme work.

Key Responsibilities:

• Build and maintain REST and GraphQL integrations with Shopify, POS, OMS and third-party business applications
• Implement OAuth flows, webhook verification and processing, retries, deduplication and error handling for production data flows
• Handle the realities of distributed data: duplicate events, out-of-order delivery, partial failures, eventual consistency
• Develop new API integrations with enterprise and SaaS platforms as the program expands
• Own SQL and BigQuery work wherever integrations require data movement or transformation
• Build automated reconciliation checks so systems of record stay in agreement
• Troubleshoot production integrations and data quality issues end to end

Requirements:

• 5+ years of backend engineering focused on API integrations between enterprise or SaaS platforms
• Strong Python in production
• REST and GraphQL integration experience on both consuming and building sides
• OAuth, API authentication, webhooks and robust error handling patterns
• Practical command of idempotency, deduplication and reconciliation design
• Strong SQL; hands-on data integration or ETL experience
• AWS deployment experience with Docker and CI/CD
• Fluent English
• Minimum 4 hours daily overlap with US Eastern time, full-time availability

Nice to Have:

• Google BigQuery
• Shopify APIs (Admin GraphQL, webhooks, Fulfillment Orders) or Salesforce Commerce Cloud
• POS, OMS, ERP or fulfillment system integration experience
• Event-driven integration patterns: queues, event buses, connectors

Job Description

Must have experience:

3+ years of professional backend development experience

Strong Python skills, including:

Object-Oriented Programming / Design
Asynchronous programming (async/await, background tasks, workers)
Experience with backend frameworks such as Django (DRF), FastAPI, or Flask

Solid understanding of backend architecture concepts:

REST APIs
Microservices
Event-driven and distributed systems
Working knowledge of:

Linux
Networking basics
Docker
Experience with tools such as Git, Jira, Jenkins

Strong analytical thinking and engineering mindset
Team-oriented approach and good communication skills
Upper-intermediate English or higher

Highly preferable experience:

Experience with relational databases (PostgreSQL, MariaDB)
Automated testing experience (Pytest or similar)
Basic frontend understanding (HTML / JS, modern frameworks)

Nice to have experience:

Cloud platforms (AWS / GCP / Azure)
Kubernetes
Go

Job Responsibilities

Design and develop scalable backend services in Python
Build and maintain REST APIs for data ingestion and exposure
Participate in architecture design (microservices, async workflows, event-driven patterns)
Integrate data from heterogeneous sources (new and legacy systems)
Work closely with frontend developers to support modern UX requirements
Ensure code quality through testing, reviews, and best engineering practices
Improve performance, reliability, and scalability of existing services
Collaborate with cross-functional teams in an Agile/Scrum environment

Department/Project Description

We are expanding the team to work on a new strategic product focused on unifying and integrating data from multiple test stations.

The project aims to:

Aggregate data from next-generation test stations, as well as legacy systems (FAST / LabView–based)
Integrate additional data sources in the future
Provide a modern backend foundation for data processing and exposure
Support a modern UX/UI layer built on top of this backend
This system will become a core data platform for manufacturing and testing of Harmonic hardware products.

Harmonic is a leading provider of innovative broadband solutions that deliver video, voice and data to communications providers around the world. GL team participates in development and QA of several generation of these solutions.

The CableOS department is about developing the new software-based network equipment which provides access to Internet/IPTV/VoIP services with using powerful servers.

It is an innovative solution for Internet Service Providers which will allow to get rid of the existing HW equipment and to migrate to the cloud, saving customers the enormous expenses for the support of huge number of hardware network equipment. Currently there are no competitors to this project in the world and Customer offers the opportunity to be at the beginning of the rapid development of the product and the opportunity to take their place in a fast-paced engineering team

At CommerceCore we don’t wait for momentum – we build it. We move fast, test boldly, and turn ideas into real results. And the real engine behind it all? Our people.

With 200+ ambitious teammates who own their work, learn fast, and lift each other up, this is a place where you’re trusted to think big and move with intent.

We’re now looking for a Senior PHP Developer who's ready to build scalable systems, shape technical decisions, and make a real impact.

WHAT YOU WILL DO:

• Drive backend architecture and technical decisions;
• Design, develop, and optimize scalable, high-load systems;
• Lead complex feature development from idea to production;
• Improve system performance, reliability, and observability (monitoring, logging, alerting);
• Mentor engineers and promote engineering best practices;
• Contribute to product decisions with technical insight;
• Identify and resolve deep technical challenges;
• Ensure security, scalability, and maintainability across systems.

WHAT WE EXPECT:

• 5+ years of hands-on experience building and maintaining scalable, highly available, high-load systems;
• Strong expertise in PHP (Laravel preferred; Symfony also valued);
• Deep understanding of MySQL database;
• Understanding of API design, including idempotency, rate-limiting;
• Familiarity with CI/CD pipelines and modern DevOps practices;
• At least basic understanding of React (or similar framework) and willingness to collaborate closely with frontend teams;
• Experience in e-commerce systems (payments, A/B testing, conversion tracking);
• Strong experience writing testable code and familiarity with software testing patterns.
• Strong focus on secure web application architecture;
• Highly autonomous, solution-oriented, and proactive.

NICE TO HAVE:

• Deep understanding of NoSQL database;
• Experience with event-driven architecture and distributed systems;
• Experience with real-time messaging systems;
• Hands on experience with various payment PSPs;

WE OFFER:

• Salary from €4500 (gross) depending on experience;
• Workplace Flexibility: flexible work arrangements, including a hybrid working model;
• Well-being benefits: Enjoy the flexibility to choose between private health insurance or a wellness budget to support your overall well-being;
• Encouraging learning environment: opportunities for professional development, including a budget for books and online courses, and time for learning;
• Collaborative, dynamic & experienced team: a culture where diverse perspectives are valued and encouraged;
• Regular team building: activities to strengthen bonds with your colleagues through regular team events and outings;
• Referral bonuses: there is an opportunity to receive a reward for recommending someone to the team;
• Modern offices: offices in Vilnius and Kaunas city centers (shower, kitchen, Foosball & other benefits for a comfortable working environment);
• Office Perks: weekly snack refills, bun Wednesdays to brighten your midweek, and company lunch on the last Friday of each month;
• Celebrations & Events: company-wide events and celebrations, such as results overviews, Christmas parties, and summer events;
• Personal Celebrations: recognition of personal milestones and celebrations, such as birthdays and anniversaries.

We are looking for a Sr Scala Developer for a major client in the Fintech sector. The project involves the development and optimization of backend components within a dynamic and technologically advanced environment.

Work mode: Full Remote

Working language: English

Engagement duration: From September until the end of April 2027

Required skills:

Solid experience in backend development

Excellent knowledge of Scala (Must Have)

Excellent knowledge of Kafka

Excellent command of English (written and spoken)

Nice to have:

Experience with Typelevel stack (Cats-Effect, Doobie)

Experience with Akka/Pekko toolkit (Http and Streams)

Experience working with microservices architectures, event streaming systems and cloud providers is also preferred. Kubernetes and AWS knowledge is a plus.

Experience and appreciation for Extreme Programming values and principles.

Experience working in financial services systems.

Comfortable working in remote-friendly teams distributed between multiple locations.

A good understanding of Agile methodologies, their principles and their ceremonies.

We’re expanding our team and looking for a Django/DRF Developer to join Dataforest. If you’re looking for a friendly team, a healthy working environment, and a flexible schedule — you’ve found the right place to send your CV.

You'll be a great fit if you have:

- 3+ years of experience with Django and it's components;

- Experience with RESTful APIs, DRF and related libraries;

- Experience with Celery and async task management;

- Experience with SQL and query optimisation;

- Experience of writing tests;

- Able to work independently and excellent in communicating challenges and issues;
 

Would be a plus:

- Experience with AWS services (EC2, API Gateways, Lambda, SQS);

- Experience with NoSQL databases (Redis, Elasticsearch, etc.);

- Experience of end-to-end implementation for new functionality;

- Experience with payment systems integrations (Stripe, Shopify, Recurly, Paypal, Braintree, etc.);

- Experience with chargeback management tools (Ethoca, RDR, CDRN, etc.);

- Understanding how to handle high load on projects;
 

What you'll do:

- Design, develop and maintain payment gateway and other integrations;

- Design and develop new features and maintain existing functionality.

- Design and develop web applications using Python/Django/Celery.

- Design, develop and maintain RESTful APIs using Django Rest Framework (DRF).

- Write clean and well-structured code that is easy to read and maintain;

- Write and maintain technical documentation.

- Write and maintain unit tests to ensure code quality.

- Optimize and maintain the security, performance, and usability of the applications.

- Collaborate with the PM/Frontend/DevOps/QA and others team members.

We ensure your growth with:

- Great networking opportunities with international clients, challenging tasks;

- Building interesting projects from scratch using new technologies;

- Personal and professional development opportunities;

- Competitive salary fixed in USD;

- Paid vacation and sick leaves;

- Flexible work schedule;

- Friendly working environment with minimal hierarchy;

- Comfortable, spacious and well-equipped office in the city center;

- Team building activities, corporate events.