Company Description MestriA is an AI document intelligence platform serving legal and financial teams across Europe, including law firms, banks, real estate servicers, debt recovery specialists, and insurers. The platform is purpose-built to handle complex, jurisdiction-specific documentation that generic AI tools cannot reliably process.

MestriA automates data extraction from judicial files and financial documents, accelerates due diligence, and delivers confidence-scored, audit-ready results with high precision. It supports multiple European languages, integrates via API with existing systems, and operates on GDPR-compliant, EU-based infrastructure aligned with the EU AI Act and other regulatory frameworks. The company is backed by EU funding, built and based in Spain, and is actively expanding across Europe with production deployments already in place.

Role Description The Senior Full-Stack Product Engineer will design, build, and scale the end-to-end web applications powering MestrIA’s EU-focused AI document-intelligence platform. As an early-stage startup, MestrIA offers the opportunity to shape both the product and the engineering foundations from the outset.

You will work closely with the founders, alongside product, data, and operations colleagues, translating complex legal and financial workflows into secure, maintainable,

production-ready software.

Day to day, you will develop responsive front-end experiences, scalable APIs and back-end services, database-backed workflows, and reliable document-processing integrations. You will work with OCR and AI services, asynchronous processing pipelines, file storage, and user-facing processing status—ensuring performance, security,

observability, and privacy-by-design throughout.

You will help improve existing codebases, testing, deployment pipelines, cloud infrastructure, and engineering practices, with particular attention to EU data residency and GDPR-aligned handling of sensitive information.





This is a full-time hybrid role based in Madrid, A Coruña, or Barcelona, combining in-person collaboration with work-from-home flexibility.

Qualifications

- Strong experience building back-end services and APIs, ideally with Python/FastAPI and/or Node.js.
- Strong front-end development skills with TypeScript, React, Next.js, HTML, and CSS; able to create responsive, accessible, intuitive interfaces.
- Demonstrated full-stack experience integrating front-end and back-end components into secure, scalable, production-ready SaaS products.
- Solid PostgreSQL and relational data-modeling skills, including migrations, query performance, and data integrity. Experience with Supabase is a plus.
- Experience with AWS cloud services, Docker, CI/CD, and production monitoring. Familiarity with ECS/Fargate, App Runner, S3, CDK, or infrastructure as code is highly

valued.
- Experience designing reliable asynchronous workflows, including file uploads, background jobs or workers, retries, processing status, and auditability.
- Comfortable integrating REST APIs, OCR, LLM, AI, or other data-processing services into web products. Experience validating structured AI outputs is a plus.
- Strong engineering practices in automated testing, code review, security, documentation, and maintainable system design.
- Awareness of GDPR, privacy-by-design, EU data residency, and secure handling of sensitive information.
- Ability to work closely with founders and cross-functional teams, communicate clearly, take ownership, and thrive in a hybrid early-stage startup environment.
- Professional proficiency in English. Spanish or another EU language is a plus, as is experience in legaltech, fintech, or document-processing products.
- Bachelor’s degree in Computer Science, Engineering, or a related field, or equivalent practical experience. Strong candidates currently completing a relevant degree,
- with demonstrable hands-on software-development experience, are also encouraged to apply.

📌 Full Stack Engineer (Comunidad de Madrid)
🏢 MestrIA
📍 Comunidad de Madrid