Middle Backend Developer (Node.js)

We are looking for a skillful Backend Developer to join one of our teams working with US clients - referrals from the high-end American IT market.
Our tech stack is built around React, Node.js and TypeScript. We are working with well-established companies and sometimes startups in their early stages (MVPs), which makes the job full of diversity and exciting challenges while crafting cutting-edge solutions.
Enjoy the flexibility of working within the Polish time zone and collaborate with clients from diverse industries such as FinTech, SportsTech, MedTech, and many others.
Salary: PLN - + VAT (B2B)
Offer:

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Required skills: 2+ years of commercial experience in Node.js, SQL and NoSQL DBs, knowledge of JS frameworks (e.g Express.js, NestJS), experience in TypeScript, SOLID and KISS, knowledge about design and architecture patterns, knows how and why Docker and GitHub Actions works, basic usage of AWS services, English B2, Polish C1

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Offer: B2B/UZL, paid days off, 100% remote (or hybrid/onsite - as you prefer), Polish time zone, flexible hours, full-time position, long-term contract, Scrum Teams

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Perks and Benefits: learning budget, budget for health insurance and sports, regular feedback, support, and real learning opportunities, access to internal Design Talks and Tech Talks, and more

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Tools you'll use: Apple MacBook Pro, Slack, GSuite, GitHub, Jira, Coda, FigJam, Claude Code

Your future tasks and duties:

- Writing readable, testable and easy-to-maintain JS/TS code with OOP flavor

- Taking ownership of backend features from understanding requirements through implementation, testing and deployment

- Writing documentation for delivered code and technical decisions

- Code review of other developers in the team, including constructive feedback and knowledge sharing

- Direct involvement with the design and modification of basic DB structures and API contracts

- Propose pragmatic improvements and proactive ideas/solutions to enhance the product and team’s work processes

- Share insights with the team to diagnose issues, communicate risks and focus on solutions

- Actively participate in project discussions, refinements and technical decision-making

- Listen to the client's needs and, after consulting the team, suggest practical solutions

- Support less experienced team members through code review, explanations and pair programming
Use AI tools responsibly in daily work, verifying and adapting results to production standards

About you - Tech skills & Experience:

- 2+ years of commercial experience in Node.js

- Good experience with at least one Node.js backend framework (e.g. Express.js, NestJS, Fastify, etc) - you know most of its basic APIs/features, worked on at least 1-2 projects involving such technologies

- Strong proficiency in TypeScript. You have practical experience with static typing, advanced types, and configuring TS compilers, treating it as your primary language to build robust and type-safe backend applications

- Potentially worked with NoSQL databases and/or in-memory databases and utilized them as a data store

- Worked with SQL databases (integration-wise and as a basic design skill) with ORM or query builder tool (ie. Prisma, Knex)

- Understands how AI/LLMs work in practice (context, prompts, limitations) and has hands-on experience contributing to AI-powered backend features (e.g. integrating LLM APIs, basic RAG flows, or simple agent-style workflows)

- Integrates AI seamlessly into daily development workflow - uses it for prototyping, boilerplate, and tests, while always verifying and adapting output to production-quality standards

About you - Soft Skills:

- English level B2 to cooperate with American clients

- Polish level C1 to communicate easily within the team

- Open-minded to new challenges (e.g. different frameworks)

- Understand the significance of MVP and prioritize the pursuit of excellence and high-quality outcomes, even amid tight project timelines.

- Communi