backend · nestjs, node.js, typescript, postgres
NestJS developer for backends that run in production.
The WhatsApp AI assistant I built runs on a NestJS backend: webhooks, a queue in Postgres, vector search, about 880 automated tests, and one deployment for all restaurants. I build backends like that for your product, or join your team to work on yours.
- Stack
- Node.js, NestJS, TypeScript, Postgres
- Operations
- Docker, AWS, Hetzner
- In production
- Tracing, error tracking, tests in CI
- Engagement
- As a project or in your team
- Working hours
- Mon–Fri 04:00–18:00 Buenos Aires 09:00–23:00 Berlin 03:00–17:00 New York
- Available from
- Q4 '26
What I build with NestJS
- APIs for web and mobile apps, with Postgres behind them.
- Integrations: webhooks from other services, verified, de-duplicated and processed through a queue.
- Multi-tenant backends: one deployment for all customers, with settings and limits per customer.
- Backends for AI features: services that call language models and act on the results, with guardrails.
In production: the backend of a WhatsApp AI assistant
Messages arrive through the WhatsApp Cloud API webhook, are verified and de-duplicated, and go through a queue in Postgres. A lock per conversation keeps replies in order, and messages sent in quick succession are answered as one. Retries with a dead-letter queue and a fixed fallback message cover failures. Each restaurant’s FAQ is found by vector search in Postgres. Tracing runs through Langfuse, error tracking through Sentry with personal data scrubbed, and about 880 automated tests, including end-to-end conversations, run in CI. Read the case study.
TypeScript from front to back
With Angular or Vue in the browser and NestJS on the server, the whole product speaks one language. One person can build a feature from the database to the screen, and the team needs one toolchain instead of two. More under Angular development.
How we can work together
- App development: a backend, or a whole product, with a written scope, a demo every week and the code in your hands.
- Staff augmentation: I join your backend team, part-time or full-time, from three months.
- Advisory and code rescue: an architecture review of your Node.js backend, or a codebase made safe to change again.
Questions
NestJS or plain Node.js?
NestJS gives a Node.js backend a fixed structure: modules, dependency injection, and a clear place for validation and tests. That pays off as soon as more than one person works on it. For a small service, plain Node.js can be enough, and I'll tell you which fits.
Can you work on our existing Node.js backend?
Yes, inside your team, or with an architecture review first: a written assessment of what works, where the risks are and what to do first.
Which database?
Postgres, also for queues and for vector search when an AI feature needs to find the right piece of text.
Where does it run?
In Docker containers, on AWS or Hetzner, or on the infrastructure you already have.