Aaron Castells

I am a pragmatic full-stack software developer with experience building reusable interfaces and backend services using React, Next.js, Node.js, Vite and Tailwind CSS. I have shipped product features, refactored legacy systems, and contributed to new product development across startups and scale-ups.

My background includes integrating third-party services (Stripe, Cabify, Deliverect), developing internal tools, and implementing AI agents and LLMs in production. I also bring experience with Golang and C#, strong database design (PostgreSQL, MongoDB, MSSQL), and DevOps practices such as Docker, CI/CD and Linux-based production environments.

I thrive in agile teams, practicing automated testing (Jest, Cypress, Sinon), hexagonal architecture principles, and collaborative development workflows using Git. I focus on building scalable, secure systems and pragmatic solutions that accelerate product delivery.