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# Fullstack / Heavy-Backend Developer (NestJS PostgreSQL)

- **Company:** Número De
- **Location:** Madrid, Spain (Remote available)
- **Salary:** €30,000.0 - €35,000.0
- **Contract:** Permanent contract
- **Skills:** Clean Code Principles, Multitier Architecture, Artificial Intelligence, Command-Query Responsibility Segregation (Software Development), Dependency Injection, Software Design Patterns, PostgreSQL, Node.Js, Next.js, TypeScript, Sql Optimization, ReactJS, Claude Code, Backend, Data Layers, Build Management, Webpack, Front End Software Development, NestJS
- **Published:** October 10, 2026
- **Apply:** https://www.adzuna.es/details/5920642038

## About the Role

* Autonomy & Resilience: You take an ambiguous or complex issue, break it down, research it, and solve it. You don't get blocked easily-you see challenges as engaging puzzles.
 * Common Sense & Pragmatism: You know when to apply an elegant architectural pattern and when a simple, direct solution is better to keep moving forward without over-engineering.
 * Open Communication: Zero fear of asking questions, raising your hand when something is unclear, or challenging ideas to propose a better alternative.
 * English Proficiency (Minimum B2): Able to communicate fluently, read/write technical docs, and participate in team discussions in English.

## Description

We are looking for a Fullstack Developer with a heavy focus on Backend who can take full ownership of features end-to-end, leveraging engineering best practices and top-tier AI tooling.

What will you do day-to-day?

 * Design and build scalable architectures: Work primarily on the core backend, designing clean systems, applying design patterns (Repository, Factory, CQRS, Dependency Injection, etc.), and ensuring maintainable code.
 * Master the data layer: Design efficient relational schemas, optimize complex queries, and get the most out of PostgreSQL and PostgREST.
 * Build robust APIs & services: Develop modular, strongly-typed backends using NestJS.
 * Targeted Frontend support: While your main strength is the backend, you'll have the autonomy to build and connect clean, functional interfaces in React (using Vite or Next.js).
 * Guide AI as a force multiplier: You'll receive a company-sponsored Claude Code Pro subscription (and access to top AI tools). Your job isn't to be replaced by AI, but to direct it-explicitly instructing it on design patterns and structuring context to multiply your output 5x.

Your Stack & Tooling

 * Backend (Core): NestJS, PostgreSQL, PostgREST, Advanced SQL, Node.js / TypeScript.
 * Frontend (Secondary): React (Next.js / Vite).
 * AI Tooling: Claude Code Pro (fully covered) to accelerate your workflow.
 * Best Practices: SOLID, Design Patterns, Clean Architecture, Testing.