Full-Stack TypeScript Developer (NestJS + Next.js)

We are hiring a full-stack developer to work on Boekie, a multi-tenant SaaS platform for automated bookkeeping aimed at the Dutch market.

You will work across two codebases: a NestJS backend (TypeORM, PostgreSQL) and a Next.js frontend (App Router, React, TypeScript). The product handles real money, so correctness matters. You will touch Stripe billing, accounting integrations (eBoekhouden, ExactOnline, KVK), AI document processing, job queues, and realtime features.

What you will do:

Build and maintain backend modules following our controller, service, repository structure
Write safe PostgreSQL migrations and design indexes for read-heavy workloads
Implement frontend features in the App Router with correct Server and Client Component boundaries
Integrate third party APIs with idempotency, retries, and proper webhook handling
Wire up LLM features and treat model output as untrusted input
What we expect:

Strong TypeScript, daily driver level
Production experience with NestJS or a similar opinionated framework
Solid PostgreSQL beyond basic CRUD: transactions, locking, query plans
Experience with multi-tenant systems and tenant isolation as a security concern
You read existing patterns before inventing new ones, and you push back on bad requirements
Nice to have: Stripe, Bull or BullMQ on Redis, ---------- , next-intl, Google Cloud APIs, accounting or fintech background, Dutch market knowledge (KVK, BTW, IBAN).

Dutch language is a plus but not required. The codebase and domain are Dutch-centric.