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# Full-Stack Engineer

- **Company:** The Vault
- **Location:** Barcelona, Spain (Remote available)
- **Contract:** Permanent contract
- **Skills:** JavaScript (Programming Language), Application Programming Interfaces (APIs), Audit Trail, Databases, Continuous Integration, Cursor, Software Debugging, Github, PostgreSQL, MongoDB, Node.Js, Query Optimization, Role-Based Access Control, Microsoft Copilot, SQL Databases, TypeScript, Workflow Management Systems, Data Logging, Mern, ReactJS, Concurrency, Indexer, AI Coding Agents, Backend, Gitlab-ci, Integration Tests, Kubernetes, Front End Software Development, JestJS, Restful APIs, Webhooks, Docker
- **Published:** November 6, 2026
- **Apply:** https://www.adzuna.es/details/5954589230

## About the Role

Must-have

 * 7+ years building production systems with Go and/or the MERN stack (MongoDB, Express, React, Node.js), plus solid React experience
 * Strong backend fundamentals: concurrency, APIs, reliability, debugging
 * Hands-on with DDD (not just buzzwords): can model domains and keep boundaries clean
 * Strong database skills across PostgreSQL and MongoDB: schema/collection design, indexing, query tuning, migrations
 * Experience with GORM and/or Mongoose (or similar ORMs/ODMs) plus comfort dropping to raw SQL or aggregation pipelines when needed
 * Frontend proficiency in React (TypeScript preferred), including state management and form-heavy admin UIs
 * Good testing discipline (Go testing, Jest/Vitest, integration tests; frontend testing basics)
 * REQUIRED: confident daily use of AI coding tools (Cursor/Copilot/etc.) with disciplined verification and secure practices

Nice to have

 * Event-driven patterns: outbox, retries, idempotency, background jobs
 * Experience with RBAC/policy engines, audit logs, fintech/compliance workflows
 * Docker/Kubernetes familiarity
 * CI/CD ownership (GitHub Actions/GitLab CI), release workflows
 * Experience with high-security systems (custody, payments, identity)

Soft skills

 * Ownership mindset: deliver features end-to-end with high quality
 * Clear communication and ability to work across teams
 * Pragmatic: balances long-term design with shipping
 * Comfortable in ambiguity and fast iteration

## Description

* Build end-to-end product features across Go and Node.js/Express backends and React frontend
 * AI-assisted development: use Cursor/Copilot/ClaudeCode (or similar) daily to accelerate delivery, refactoring, and test generation-while verifying outputs and keeping code clean
 * Design backend services using DDD patterns (bounded contexts, aggregates, domain events), clean layering, and pragmatic architecture
 * Implement data models and migrations across PostgreSQL and MongoDB, using GORM, Mongoose, or raw queries where appropriate
 * Build and maintain REST APIs (and webhooks/event-driven workflows where needed) in both Go and Node.js/Express
 * Implement frontend flows in React (TypeScript): dashboards, admin workflows, status lifecycles, audit views
 * Ensure correctness and observability: structured logging, metrics, tracing, and production-ready error handling
 * Contribute to security fundamentals: RBAC, least-privilege access, safe secrets handling, and audit trails
 * Own quality: unit/integration tests, contract tests, and CI pipelines