Senior NestJS developer for enterprise-grade backends
Based in Wroclaw, Poland · EU timezone · Available for new projects
NestJS is my go-to for backends that need structure. Dependency injection, module architecture, guards, interceptors, and proper testing — the patterns that make enterprise applications maintainable at scale. I build backends that your team can actually understand and extend.
Multi-tenant SaaS backends
Tenant isolation at the database or schema level, per-tenant configuration, and billing integration. Built with NestJS modules for clean separation of tenant logic from core business features.
APIs for regulated industries
Audit logging, data encryption at rest, GDPR-compliant data handling, and role-based access control for fintech, healthtech, and legal platforms where compliance isn't optional.
Complex RBAC and authorization
Fine-grained permission systems with custom guards, CASL integration, and hierarchical role inheritance. Beyond simple admin/user — supporting team-based access, resource ownership, and dynamic permissions.
Microservices with NestJS
Distributed backends using NestJS microservices transport layer — TCP, Redis, RabbitMQ, gRPC, or Kafka. Shared DTOs and validation across services with proper contract testing.
Backend for mobile and web apps
Unified API serving both mobile (React Native) and web (Next.js) clients. Versioned endpoints, push notification dispatching, file upload handling, and real-time updates over WebSockets.
Module architecture
I design NestJS module boundaries that match your domain. Feature modules, shared modules, dynamic modules for multi-tenancy. Clean imports, no circular dependencies, and each module testable in isolation.
Dependency injection
Custom providers, factory providers, async module configuration. I use DI to make code testable and swappable — not as a ceremony. Every service has a clear contract and can be mocked in tests.
Guards, interceptors, and pipes
Authentication guards, logging interceptors, validation pipes with class-validator or Zod. The NestJS request lifecycle used properly to keep controllers thin and cross-cutting concerns centralized.
TypeORM and Prisma integration
Database layer with proper repository patterns, transactions, migrations, and seeding. Complex queries with QueryBuilder when the ORM isn't enough. Database-level constraints and indexes for data integrity.
Testing at every level
Unit tests with mocked providers, integration tests with a real database, E2E tests with Supertest. NestJS makes testing straightforward — I take advantage of that fully. Every module has its own test suite.
OpenAPI and documentation
Auto-generated Swagger docs from decorators, keeping documentation in sync with the actual code. API versioning, request/response examples, and client SDK generation from the OpenAPI spec.
Domain modeling
I map the business domain to NestJS modules, services, and entities. We define the API contracts, database schema, and integration points before writing application code.
Test-driven development
I write tests alongside features. Every endpoint has integration tests, every service has unit tests. The test suite is your safety net for future changes and team onboarding.
Production-ready handoff
Deployed with Docker, health checks, Swagger documentation, and structured logging. Your team gets a codebase with clear patterns they can follow for every new feature.
Express gives you freedom but no structure. NestJS gives you dependency injection, module system, and decorators that enforce consistency across a growing codebase. For small APIs, Express is fine. For anything your team needs to maintain for years, NestJS pays for itself.
Yes. I do incremental migrations — wrapping existing Express middleware, moving routes to NestJS controllers one by one, and introducing dependency injection gradually. No big-bang rewrite needed.
Prisma is my default — it has the best TypeScript support and migration tooling. For projects that need complex queries or database-level features, I use TypeORM or Drizzle. The choice depends on the project's query complexity.
Yes. JWT + refresh tokens, OAuth 2.0 social login, session-based auth, API keys — I implement what fits the use case. For authorization, I build custom guards with CASL for fine-grained, type-safe permission checking.
Yes — it has built-in microservices support with multiple transport layers (TCP, Redis, RabbitMQ, gRPC, Kafka). I use NestJS for both monolith and microservices architectures, choosing based on actual project complexity.
I work on a daily or monthly rate depending on the engagement. Book a free 30-minute call and I'll give you an honest estimate based on your project scope.
Ready to hire a senior NestJS developer?
Book a free 30-minute technical call. I'll review your requirements and tell you honestly if I'm the right fit.