Senior Backend Engineer (NestJS)

About the role

We are seeking a Senior Backend Engineer with deep expertise in NestJS to design, develop, and maintain scalable backend services and APIs. The role involves building secure, production‑grade applications for a fintech/payments platform.

Key responsibilities

• Design and extend REST and WebSocket APIs using NestJS modules, controllers, services, DTOs, guards, interceptors, and pipes.
• Model and evolve data in PostgreSQL (TypeORM) and MongoDB (Mongoose), handling migrations, indexing, and query optimisation.
• Implement policy‑based authorization, JWT/OAuth2 authentication, and role‑based access control.
• Build asynchronous processing with queues (BullMQ), scheduled jobs, and event‑driven flows.
• Integrate third‑party services, generate PDFs/Excel/CSV files, and handle large‑file processing.
• Write unit and integration tests, maintain OpenAPI documentation, and use Docker for local development.

Required profile

• 4+ years of production API development with NestJS and Node.js in TypeScript.
• Strong experience with PostgreSQL, TypeORM, MongoDB, Mongoose, and Redis.
• Hands‑on knowledge of authentication/authorization mechanisms (JWT, OAuth2, SSO, CASL).
• Proficiency in testing frameworks (Jest, Supertest) and containerisation (Docker, Docker Compose).

Required skills

• NestJS
• Node.js
• TypeScript
• PostgreSQL & TypeORM
• MongoDB & Mongoose
• Redis & BullMQ
• JWT, OAuth2, SSO, CASL
• OpenAPI/Swagger
• class-validator, class-transformer
• Jest, Supertest, Testcontainers
• Docker, Docker Compose
• Socket.IO (optional)
• Puppeteer (optional)
• AWS, Terraform, GitHub Actions (optional)
• Angular (optional)