Gilberto S
IPA /ˈɡɪl.bə.to/, full-stack
TodayNovember 01
I'm a programmer with an eye for design. I'm also a fan of open-source and often contribute to the tools I use.
I primarily specialize in web technologies, including: Web Performance · Accessible Interfaces · Design Systems · Data visualizations · AI Engineering
I take pride in owning critical parts of a product and pushing it forward. I believe a strong focus on fundamentals drives the greatest progress.
Outside of work, I'm just as energetic. I'm a swimming athlete who enjoys traveling , the gym, and cool looking watches.
Experience
Over the past years, I've been super lucky to work with some amazing people on a variety of great projects, ranging from open-source libraries to large-scale applications that are both challenging and rewarding.
Cache App
Created Cache, a browser-first app that brings bookmarks and saved content from different platforms into one searchable AI workspace. It has over 250 users. I built the data ingestion pipelines, normalized metadata across sources, and made search and filtering fast on the client. A Postgres-backed sync layer keeps it responsive with large collections.
ItemIQ
VisitBuilt the foundations of a platform for Amazon FBA and FBM sellers, replacing spreadsheet-heavy catalog workflows with automated profit analysis, opportunity detection, and restocking suggestions. I designed and implemented core backend and data pipelines in Python and TypeScript, covering ASIN ingestion, SP-API integration, fee and margin computation, and issue detection. Sellers use it to monitor thousands of ASINs, catch suppressed Buy Boxes and miscategorized listings, and save money.
Infactura
VisitI was a core developer on Infactura, an online invoicing platform for freelancers and SMEs in Spain. The focus is compliant electronic invoicing and faster online payments. I helped build the multi-tenant app with TypeScript, React, Next.js, Prisma, and Postgres, including invoice templating, recurring billing, payment links, and tax logic. I put real care into the UX, typography, and branded documents.
Accenture summer internship
Worked with a team to prototype an agentic CV-parsing and job-matching system, including LLM orchestration, structured extraction, and explainable recommendations.
MinuteDebate
Created MinuteDebate, a real-time debating game where two anonymous players argue a randomly assigned topic for 60 seconds each while an AI judge scores persuasion and coherence. I designed the game loop, the interface, the low-latency real-time interactions, and an LLM-powered evaluation pipeline so players receive feedback the second each turn ends.
gsmt.dev
Designed and developed as my portfolio and a live playground for interaction design, typography, and performance experiments. I test animations, layout systems, and component abstractions here before they make it into real work.
Developer tools & UI utilities
Built minimalist power tools, like cleaning-mode, an Electron utility that temporarily disables keyboard and touch input so you can clean your device safely, alongside many developer libraries like use-selectify, use-gif, and react-bypass… I care about ergonomic APIs and small, well-scoped abstractions.
Creative coding & simulations
Created a range of creative coding experiments including Mandelbrot fractal renderers, chaos-equation visualizers, shaders, and fluid and particle simulations. These explorations pushed my understanding of WebGL, canvas, numerical methods, and browser performance.