Guillem Garcia Sans

Senior Backend Developer · Buenos Aires, Argentina · Remote · Spanish
Email: guillemgarcia15@gmail.com
LinkedIn: https://www.linkedin.com/in/guillem-garcia
GitHub (old *): https://github.com/alarbada
GitHub: https://github.com/guillemus
Website: https://guillemus.com

Summary

Senior backend developer focused on Go, TypeScript, and Postgres data systems.
Built connectors and replication pipelines across Kafka, SQS, and RabbitMQ.
Strong in CI/CD and Docker-based integration testing; kept CI green and integration tests reliable.

Skills

• Go, TypeScript, Python
• Backend APIs, microservices, data replication
• Messaging: Kafka, Pulsar, RabbitMQ, SQS
• Databases: PostgreSQL, MySQL, MongoDB, SQLite
• Cloud: AWS (S3, SQS, EC2), Cloudflare Workers/Pages, DigitalOcean
• Edge/Serverless: Vercel, Turso
• CI/CD: CircleCI, GitHub Actions
• Testing: TDD, unit/integration testing
• Frontend (supporting): React, Next.js, React Native, Qwik, htmx

Experience

Lemon.io — Back End Developer
Dec 2023–Present · Remote (Spain)

• Built open‑source database connectors for Conduit.io.
• Owned CI for each connector: GitHub Actions + Dockerized integration tests across Pulsar, RabbitMQ, MySQL, and ActiveMQ; stabilized pipelines and reduced flaky test failures.
• Improved MySQL connector throughput by 200%.
• Implemented data replication pipelines using Kafka; integrated Pulsar, RabbitMQ, SQS.
• Developed backend services in Go focused on reliability and data movement.

Cocunat Natural & Toxic Free — Senior Web Developer
Jan 2023–Nov 2023 · Barcelona, Spain

• Built TypeScript, Go, and Python microservices with React/React Native apps.
• Delivered edge services with Next.js, Vercel, Cloudflare Workers/Pages, Turso.
• Managed AWS SQS/S3/EC2 and DigitalOcean Postgres; CI/CD via CircleCI/GitHub Actions.
• Built fast Qwik landing pages and worked in TDD style.

Spiral Platform — Full Stack Engineer
Aug 2019–Jan 2023 · Buenos Aires, Argentina

• Migrated PHP monolith to Node.js and Go microservices.
• Improved MercadoLibre → Postgres import performance 50% by rewriting PHP script in Go.
• Built multiple TypeScript React SPAs.
• Managed PostgreSQL on AWS RDS; built MongoDB aggregation pipelines.
• Built web scraping services with Puppeteer and Apify.

Ditec Comunicaciones — Full Stack Developer
Feb 2019–Jul 2019 · Barcelona area, Spain

• Built React SPA for audio source management in operating rooms.
• Implemented Node.js/Express API server.
• Achieved 80%+ unit/integration test coverage using Jasmine.

Consultia IT — Intern
Oct 2018–Feb 2019

• Maintained legacy Java full‑stack applications.
• Basic SQL Server database management.

n‑tropia — Intern
Sep 2017–May 2018 · Girona, Spain

• Implemented responsive designs with HTML/CSS.
• Maintained PHP sites; managed MySQL databases.

Whitesheep‑IT — Intern
Jun 2017–Aug 2017 · Cologne area, Germany

• Developed and maintained PHP applications.

Education

Formación Profesional (2‑year vocational program), Spain · 2016–2018

Languages

Spanish (Native), English (C1)

(*): I lost my github account due to a github oauth code bug, and all my previous opensource work is there.