Principal Backend Engineer (NestJS / TypeScript / Microservices)

About the role

Confiz is looking for a Principal Backend Engineer to lead the design and delivery of high‑performance, secure backend services. You will work on a suite of microservices built with NestJS and TypeScript, shaping architecture that powers digital experiences for global enterprises.

Key responsibilities

• Own the full lifecycle of NestJS microservices: define module boundaries, version APIs, and ship resilient, well‑tested services.
• Design internal communication patterns using REST, gRPC, and event‑driven approaches, handling retries, timeouts, back‑off and circuit breakers.
• Implement robust JWT authentication with access/refresh lifecycles, rotation, validation and revocation mechanisms.
• Integrate payment gateways (Stripe, Adyen, Braintree) with idempotent operations, handling captures, refunds, disputes and signed webhook reconciliation.
• Build and consume secure webhooks, enforce payload contracts, verify signatures/HMAC and ensure idempotency with retry and dead‑letter queues.
• Enable real‑time features via WebSockets (NestJS Gateways, Socket.IO or ws), applying rate‑limiting and security at scale.
• Leverage Redis/Valkey for caching, distributed locks, queues/streams and pub/sub while mitigating hot‑key scenarios.
• Create efficient multi‑stage Docker builds, health‑checks and orchestrate local development stacks with docker‑compose.
• Write comprehensive unit, integration and end‑to‑end tests (Jest, Supertest) and add schema validation (class‑validator, OpenAPI).
• Collaborate across product, frontend and data teams, review pull requests and produce concise design documentation.

Required profile

• 5+ years of professional backend development experience, with at least 5 years using NestJS and TypeScript in production.
• Strong expertise in Docker, docker‑compose and multi‑stage container builds.
• Proven experience designing microservice architectures, API versioning, idempotency and eventual consistency patterns.
• Hands‑on experience implementing JWT in distributed systems.
• Demonstrated work with payment integrations and webhook security.
• Experience building and scaling WebSocket‑based real‑time features.
• Solid SQL knowledge (PostgreSQL or MySQL) and ORM experience (TypeORM or Prisma).
• Familiarity with security best practices (OWASP, secrets management) and observability tooling (structured logs, metrics, tracing).

Required skills

• NestJS
• TypeScript
• Docker & docker‑compose
• REST, gRPC, event‑driven architectures
• JWT authentication
• Stripe, Adyen, Braintree
• Webhooks (HMAC, signatures)
• WebSockets (Socket.IO, ws)
• Redis / Valkey
• PostgreSQL / MySQL
• TypeORM / Prisma
• Jest, Supertest
• class‑validator, OpenAPI
• Kong API Gateway
• Kubernetes, Helm
• Istio / Linkerd
• NATS, Kafka, RabbitMQ