Senior Backend Developer (Node.js / NestJS)

Quick Facts

• Role: Senior Backend Developer (Node.js / NestJS)

• Focus: backend microservices, AWS migration, reliability, and secure APIs

Description

You will migrate serverless AWS Lambda functionality to containerized services running on AWS ECS, incrementally during live production traffic, with parallel validation and rollback paths. You will design and maintain TypeScript/NestJS backend microservices on AWS ECS with a strong focus on scalability and clean service boundaries. You will monitor service reliability, diagnose production issues to root cause, and implement well-tested RESTful APIs with security (authN/authZ) and performance in mind.

Responsibilities

• Migrate functions from AWS Lambda to ECS containerized services incrementally on live production traffic

• Implement parallel validation and rollback strategies

• Design and maintain backend microservices in TypeScript and NestJS on AWS ECS

• Monitor reliability, troubleshoot incidents, and drive issues from symptom to root cause

• Write testable code with unit and integration test coverage integrated into CI pipelines

• Document architecture decisions, runbooks, and knowledge-transfer materials

• Design and document RESTful APIs with security and performance considerations

Requirements

• 6+ years of commercial experience building backend or full-stack systems in production environments using TypeScript/JavaScript, Node.js, and NestJS

• Production experience with microservices architecture and event-driven patterns

• Experience designing schemas and optimizing queries in PostgreSQL, MySQL, and/or MongoDB

• Experience with caching patterns using Redis

• Advanced AWS knowledge: deploy and maintain containerized workloads on ECS/Fargate and related services (API Gateway, SQS/SNS, CloudWatch, IAM)

• Experience migrating live production systems without downtime for end users

• Fluent Polish and English

Benefits

• Project-based cooperation with payment by stages and acceptance protocols for deliverables

• Administrative and billing support via Connectis

• Participation in industry events and technology meetups

• Flexible B2B engagement

• 100% remote delivery

• Fast and remote process

• Referral bonus: 5,000 PLN for recommending friends