Backend
- Java 8–21
- Spring Boot
- Node.js
- NestJS
- REST APIs
- SQL · MySQL · PostgreSQL
- MongoDB
- Hibernate / JPQL
Developer & founder · Valencia
Facundo Costa Zini
Full-stack engineer and software architect. I ship products, and I build companies.
01 — Bio
Hands-on engineer. Product owner. Founder.
Full-stack developer and founder, with more than 13 years building production software. Core craft is backend and frontend together — Java, Spring Boot, Angular, React, TypeScript and Node.js — from architecture and APIs to the UI people actually use.
Fintech, healthcare, restaurants, travel, HR — among others. The through-line is picking up whatever the project is and shipping it. Iterpax is a passion project: a B2B SaaS for travel agencies, covering product discovery, architecture and hands-on development.
In Buenos Aires, ThinkUp Studios meant leading small teams and shipping client work across web and mobile. Owning the loop end to end, with Cursor and OpenAI every day to move faster and smarter.
Gamer: video games, escape rooms, board games, puzzles you crack with other people. That curiosity is why Carcassonne Scores and Keepout exist.
02 — Stack
The tools I use.
Frontend
- Angular
- React
- TypeScript
- Tailwind CSS
- SCSS
Architecture
- Software architecture
- DDD / SOLID / Clean Architecture
- Docker
- GitLab CI/CD
- Kubernetes
- Microservices
- OAuth2 / Keycloak
Product
- Founding / product ownership
- Scrum / Agile leadership
- AI-assisted development
- Cursor · OpenAI
03 — Experience
I adapt to what the work needs.
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Nov 2025 — now
Full Stack Developer Cegedim
Remote · Maiia BI
The challenge
A healthcare analytics platform that has to work across several medical products — not one dashboard, a system. Query load, fine-grained permissions, pivot tables and standalone deployments all collide. I took the async query path (WebSockets, background jobs, Redis) and worked the multi-tenant backoffice with OAuth2/UAA, across frontend, backend, DevOps and CI/CD.
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May 2025 — Sept 2025
Sr Java Developer UHS
Valencia, Spain · Remote USA
The challenge
A million events a day, on a custom queue that had to behave like RabbitMQ without being RabbitMQ. Backend services in Java 17 and Spring Boot, SOLID and DDD. Kubernetes to keep the microservices reliable and scalable, and the load actually distributed.
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2024 — 2025
Freelance Full Stack Developer Magnético
Remote
The challenge
Two different problems. One was building a commissions and employee platform from scratch (NestJS, React, Tailwind, Docker, GitLab CI/CD). The nastier one was dropping React (Polotno) inside an Angular app without breaking lifecycle and rendering. Both shipped to production in October 2025.
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2023 — now
Founder Iterpax Studios Passion project
Valencia, Spain
The challenge
Travel operations still live in spreadsheets and chats. The bet was a modular B2B SaaS — reservations, operations, finance — on a multi-instance architecture: Java 17–21, Spring Boot, Angular, MySQL and MongoDB, with secure APIs. I still own discovery, architecture and delivery end to end as a passion project, with a small team. Client provisioning used to take days; GitLab CI/CD and containerized deploys brought it down to hours.
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2021 — 2024
Full Stack Developer Willdom
Valencia, Spain
The challenge
Two projects, two different goals. A health-insurance chatbot in Node.js, Angular and MongoDB. And Java 8 fintech systems that had to keep running in production.
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2017 — 2021
Founder & Lead Developer ThinkUp Studios
Buenos Aires, Argentina
The challenge
One project at a time is boring — why not 15? I led two teams across 15+ client projects and built internal frameworks so a feature that took a day or two shipped in under an hour, plus GitLab CI/CD and AWS Lambda/S3 for image processing.
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2012 — 2017
Full Stack Developer — Architect Conexia
Buenos Aires, Argentina
The challenge
Healthcare management systems with a team of four. The architecture was fighting us. I redesigned the core around MVC and microservices so we could actually move under Scrum, instead of negotiating with the codebase every sprint.
04 — Projects
Companies I founded. Products I shipped.
Passion project
Iterpax
Modular B2B SaaS for inbound travel agencies: reservations, operations and finance. Multi-instance architecture, secure APIs, Java 17–21 / Spring Boot / Angular, MySQL and MongoDB. I founded it, and I keep building it as a passion project.
- Modular multi-instance architecture with secure APIs.
- Stack: Java 17–21, Spring Boot, Angular, MySQL, MongoDB, Docker.
- GitLab CI/CD containerized provisioning: onboarding from several days to a few hours.
- Roadmap for OpenAI-powered support, operations, reporting, documents and workflow automation.
Live
Carcassonne Scores
Mobile-first scorekeeper for Carcassonne, the well-known board game. A personal product I designed, built and deployed.
carcassonne.costazini.com.arWork in progress
Keepout
Angular game prototype — “How long can you keep them out?” Live demo on Firebase Hosting.
keepout-thinkup.web.appPrevious venture
ThinkUp Studios
Software studio I co-founded in Buenos Aires before Iterpax. Web, mobile, 15+ client projects.
thinkup.com.ar05 — Play
Gamer. Video games. Escape rooms. Board games.
I play. A lot. Video games, escape rooms, board games — anything that is a system you have to crack with other people. I like puzzles, rules, and the moment a messy problem clicks.
That is also why Carcassonne Scores and Keepout exist: products I build because I actually want to use them.
- Gamer
- Video games
- Escape rooms
- Board games