Senior Node.JS Developer
Summary
Senior Node.js developer to lead a Backend-for-Frontend (BFF) service for an AI-powered health-tech mobile coaching platform, mentoring engineers and owning architecture decisions on AWS.
Role summary
As Senior NodeEngineerYou partner with the engagement Tech Lead on architecture, you set the bar on code quality, you mentor mid-level engineers as the squad grows, and you take direct ownership of the gateway service after the knowledge-transfer period closes.
Whatyou'lldo
First 90 days
- Read and document the existing BFF codebase alongside the outgoing engineering team
- Produce a quality baseline: test coverage, TypeScript strictness, lint compliance, dependency freshness, CI duration, flake rate
- Lead the knowledge-transfer sessions for the BFF service from the client's team
- Identifythe highest-risk subsystems and proposestabilisationplans
- Set the squad's code-review standards, branching model, and definition of done
Ongoing
- Own architecture decisions for the BFF service
- Lead design reviews for new endpoints, especially the AI integration surface
- Pair with mid-level engineers and review their work
- Represent the BFF squad in cross-team architecture discussions
- Participate in on-call rotation once we take production ownership
Kogo poszukujemy?
We are partnering with a US-based health-tech company on the takeover of a production AI-powered mobile coaching platform. The platform serves real users today via iOS + Android apps and a microservices backend on AWS. You will join the Polish team responsible for the platform's Backend-for-Frontend (BFF) and supporting Node services as they transition from the original engineering team to ours.
Must-have skills
- 5+ years Node.js in production, 3+ yearsNestJS
- Strong TypeScript — strict mode, generics, type narrowing,no any-as-escape-hatch
- NestJSdepth: modules, providers, DI scope, guards, interceptors, pipes, custom decorators
- REST API design at scale; familiarity with BFF / API-gateway patterns
- GraphQLor schema federation comfort (not required to be primary stack)
- MongoDB in production — Mongoose or native driver, schema design, indexing
- Auth0 integration — both user authentication flows and Machine-to-Machine (M2M) client credentials
- AWS production experience — ECS or EKS, IAM, VPC, RDS,ElastiCache
- CI/CD on GitHub Actions
- Distributed tracing and structured logging in production environments
- Comfortable writing tests (Jest) and raising coverage on legacy code