I build backend systems that stay correct at scale.

I am a backend engineer. For the last few years I have owned the systems where mistakes cost money: subscription lifecycles, recurring billing, payments across cards, PayPal, Apple Pay and in-app purchases, and the edge cases in between, for a platform with hundreds of thousands of users.

I care about systems that stay correct under pressure: event-driven architectures, idempotency, cross-system consistency, and migrations with zero downtime. Outside work I build products for problems I have myself, and I am pursuing degrees in Mathematics and Physics at UNED.

1. Senior Software Engineer

   Reverse Health · Remote · Barcelona

   Jul 2023 — Nov 2026

   Core monetization team, owning subscriptions, billing and payments for a platform serving hundreds of thousands of users.

   • Designing an event-driven billing platform from the ground up to replace the legacy architecture: NestJS on Cloud Run, PostgreSQL, Pub/Sub, Terraform.
   • Zero-downtime migration: event-driven synchronization so legacy and new systems coexist while traffic moves gradually, with no disruption to purchases, renewals or revenue.
   • Subscription lifecycle: trials, coupons, recurring billing, upgrades and downgrades, pauses, retention offers, refunds. Proration, billing-interval changes and cross-system state consistency.
   • Failed-payment recovery (dunning), refund flows, and idempotency and integrity guards against race conditions.
   • Payments across cards, PayPal, Apple Pay and in-app subscriptions, plus transactional email, SMS and push, and marketing attribution pipelines.
   • Production ownership: incident resolution, DLQ replays, cross-service tracing, automated sandbox e2e validation, data-repair tooling, and internal APIs for support and partners.

   TypeScript · Node.js · NestJS · PostgreSQL · Pub/Sub · GCP · Terraform

2. Software Engineer

   Colvin · Barcelona

   Mar 2021 — Apr 2023

   Backend and full-stack work on the B2B and B2C e-commerce platform.

   • Designed new product data standards with Domain-Driven Design, improving data consistency and accuracy.
   • Integrated financial processes into an external ERP through RabbitMQ events with exponential retry logic.
   • Built the B2B orders flow with Hexagonal Architecture, and a B2B sales dashboard for managing sales and incidents.
   • Cut B2B integration time and memory with Redis caching and RabbitMQ queues, enabling real-time stock synchronization.

   TypeScript · Node.js · RabbitMQ · PostgreSQL · Redis · React

3. Software Developer Intern

   Colvin · Barcelona

   Oct 2020 — Mar 2021

   • Built B2C packs on a queue-based, event-driven architecture to manage stock transactions.
   • Shipped a partnership dashboard for partners to manage roles, promotions and commissions autonomously.
   • Built the ambassadors profile area with React and Redux.

Apps

• AxiomDaily mental math puzzles. Five game modes, four difficulty levels, one short session a day.
  500+ usersWeb · iOS
• AprofyStudy planner with session timer, daily plans, progress stats and exam countdowns.
  5k+ usersiOS
• PuttsyThe golfer's record. Log rounds by total, hole or club, and read the trends in your own numbers.
  iOS
• TheoremVaultLearning notes and proven theorems across Mathematics, Physics and backend development.
  Web
• FocuStateA minimal Pomodoro timer with customizable sessions, tasks and a distraction-free zen mode.
  Web

Open source & other work

• Hand2TeXTurned handwritten equations in images or PDFs into LaTeX, with live preview and .tex export.

  Web · offline
• multigrepRecursive query and regex search over UTF-8 files, written in Rust.
  Rust
• nvim.kickstartMy Neovim configuration, tuned into a complete development environment.
  Lua
• Unlimited SheetsGoogle Sheets add-on with advanced SEO custom functions.
  Apps Script
• Escape MeDiscover and rate escape rooms.
  Bootcamp project
• Forecasting methods comparisonEngineering thesis comparing prediction methods.
  UPC · Thesis

• BSc MathematicsUNED

  2024 — Present
• BSc PhysicsUNED

  2023 — Present
• Web Development BootcampISDI Coders

  2020
• BSc Industrial EngineeringUniversitat Politècnica de Catalunya

  2015 — 2019

Happy to talk about billing systems, distributed architectures, or anything in mathematics and physics. Email is the fastest way to reach me.