Juan IgnacioVeltri
Senior Full Stack Engineer · Buenos Aires, Argentina
Profile
I build fast, secure products for fintech, security and the web.
Eight years shipping software, from Mercado Pago's payment tools to Pomelo's fintech platform and Strike's offensive-security products. I work across the whole stack: React and React Native on the front, Node services and Postgres behind them, and the infrastructure that keeps it all running. I care about systems that stay fast, observable and secure as they grow. Today I build my own products and take on a few projects at a time.
Experience
Strike
2025 – 2026Offensive security
- Sr Software EngineerJan 2025 – Mar 2026
- Led full-stack initiatives at a cybersecurity company focused on offensive security and continuous pentesting.
- Architected security-first platforms that integrate threat-intelligence flows with high-performance services.
Pomelo
2022 – 2024Fintech infrastructure
- Software Developer SrFeb 2024 – Dec 2024
- Promoted to senior: led complex technical initiatives and mentored junior developers.
- Delivered high-impact work on the fintech platform with React, Next.js, Node, NestJS and GraphQL.
- Software Developer SSrFeb 2022 – Jan 2024
- Built and maintained critical fintech applications across frontend and backend.
- Shipped scalable solutions and improved developer experience across the platform.
Mercado Pago
2017 – 2022Payments · Mercado Libre
- Software Development SSr AnalystFeb 2021 – Jan 2022
- Led payment-integration tooling with React, Node and MySQL.
- Ran monitoring on Datadog, Kibana, New Relic, StatusPage and Tableau; worked on vulnerability assessment.
- IT AnalystAug 2019 – Feb 2021
- Built payment-service applications across frontend and backend, and kept the platform stable through monitoring and data analysis.
- IT AssistantOct 2018 – Jul 2019
- First software role: React, Node, MySQL and Git, with platform monitoring on Datadog and Kibana.
- BackOffice · Customer ExperienceOct 2017 – Oct 2018
Selected work
Products I designed, built and run end to end — web, mobile and desktop.
7 projects
01Guerras Políticas
Real-time PvP strategy game: Tribal Wars-style conquest with Argentine political satire.
An authoritative Fastify + Socket.IO game server, a procedurally generated world drawn as a PostGIS Voronoi map with deck.gl vector tiles, BullMQ workers and four payment providers. On the web, App Store and Google Play.
Next.js 16 · Socket.IO · PostGIS · deck.gl · BullMQ · Expo
02Indicia
Detective logic puzzles: read the clues, catch the jewel thief.
A Next.js web app and an Expo app that draws the board with Skia + Reanimated, on a Hono + Zod serverless API with in-app purchases, Mercado Pago and ads.
Next.js 16 · Expo · Skia · Hono · RevenueCat · Neon
Linux · macOS03UK MiPortal App
Universidad Kennedy's Silverlight apps, running again on Linux and macOS.
Silverlight was discontinued in 2021 and the university's viewer only runs on Windows. I built Plata, an open-source Silverlight player on OpenSilver and WebAssembly: it reads the original .xap, adapts its assemblies to modern .NET and runs it in a tabbed desktop app, with a network gatekeeper that enforces Silverlight's access policies. Signed and notarized for macOS.
C# · .NET · OpenSilver · WebAssembly · Photino · xUnit
04Polopage
The global platform for the polo community.
Player directory filtered by handicap, rank, country and club, a services marketplace, news, realtime community chat and surveys with reward credits. Bilingual, on a tRPC + Hono API.
Next.js 16 · tRPC · Hono · Drizzle · Ably · Cloudflare R2
05Puntify
A score keeper for any game, on iOS and Android.
Scores, history and player stats across game formats. Built with React Native and Expo, and published on the App Store and Google Play.
React Native · Expo · TypeScript · iOS · Android
06SIU Bot
Automatic course enrollment for SIU Guaraní: 28 universities, 148+ programs.
A sub-minute cron that races credentials in parallel, AES-256-GCM encryption at rest, exponential backoff with Cloudflare and captcha detection, and jittered staggering to stay under rate limits.
Next.js · Drizzle · Neon · Vercel Cron · Cheerio · AES-256-GCM
07TMS Construcciones
Client projectPremium website for a Patagonian construction company with 30+ years of history.
Showcases its developments in the Alto Valle of Río Negro and Neuquén, near Vaca Muerta, with aerial footage, 3D renders, smooth animations and a bilingual site.
Next.js · TypeScript · Tailwind CSS · GSAP · Three.js · next-intl
Have something worth building? Let's talk.
juanii.veltri@gmail.com