Andrés Montero — Senior Software Engineer in Costa Rica

Anyone buying a used car in Costa Rica wants what the public vehicle registry knows about it — make, model, year, technical details, fiscal value, whether anything is registered against it. Getting to that is a chore, and the answer is not something you can link to, share, or read comfortably on a phone.

Built and shipped the whole thing solo — Django 5 and PostgreSQL behind, server-rendered HTML in front, and the scraper that keeps it fed running as a Lambda that shares nothing with the web app except a pure parser it can import without a database or a settings module.

Live and indexing. A vehicle page arrives in under 5 KB gzipped with no client-side JavaScript at all — the only script tags on it are structured data, and a test fails the build if a page outgrows its budget.

Physiotherapy patients had no simple way to manage their care and progress between sessions.

Founded and built the product — defining direction, designing the digital experience, and shipping the platform.

Still in MVP — built to keep physiotherapy patients engaged between sessions and give clinics a lighter way to manage recovery.

A specialized chronic-pain and mental-health clinic in Costa Rica — coordinating rheumatology, neurology, psychiatry, and physical therapy — needed a credible, search-visible website that earns patient trust and turns visitors into booked evaluations.

Designed and built the entire site solo in Next.js 16 / TypeScript — trilingual (ES/EN/PT), with SEO at its core to grow the clinic's patient base through search.

Organic search is the site's #1 channel — ~50% of users and 390 sessions in its first six months, ahead of direct and social.

Onsetto helps banks win a business's core operating account by automating the switch — which hinges on reliably parsing uploaded bank statements and on engineering foundations a fast-growing team can build on.

Built Auto Switch Click, one of Onsetto's core features — a one-click switch that moves a business's core operating account automatically — and hardened the statement parser for the messy real-world PDFs it couldn't handle.

Smoother onboarding for the whole dev team — and the work earned enough trust that I'm now building a new engineering team in Costa Rica.

The world's most popular survey platform runs on a large, long-lived codebase and cloud estate that has to stay reliable and maintainable as it scales across many AWS accounts.

As a Senior Software Engineer I modernized core platform components — AWS-native migrations, legacy refactors, and Terraform-managed infrastructure across multi-account environments.

More reliable, maintainable platform foundations — safer changes and cleaner infrastructure across the org's AWS estate.

A real-time fraud and risk platform needed modernized services, hardened inter-service security, and broader automated test coverage to scale safely.

Modernized Python services on the fraud and risk platform — hardening inter-service auth, expanding automated testing, and contributing ADRs, secure ADF data pipelines, and Grafana/Lambda observability.

A more secure, better-tested, and more observable fraud-and-risk platform — safer to change and scale.