Software Engineer · Uruguay · Available for freelance work
MateoCarranza
I build web and mobile products, and I’ve led the teams that make them.
Touch the water
About
I’m passionate about teamwork. It brings out the best in me, and I try to pass that energy on to everyone I work with.
I started as a full-stack developer at Zeppelin Labs. Three years later I became Engineering Manager and led several projects and teams, without stepping away from the technical side. In 2025 I went independent to get back to building things with my own hands.
How I work
I like to join from the first conversation, when the scope and the estimate get decided. Projects get automated tests, CI checks, error monitoring and analytics from day one, and clients hear from me every week.
I use Claude Code throughout, for planning, reviews and tests as well as for writing code.
Experience
- 2025–nowFreelance Software EngineerIndependent · Orbe (now as CTO), SweetPark and my own products
- 2021–2025Engineering ManagerZeppelin Labs · Envato ImageGen, Deblank, Crafty Amigo
- 2018–2021Full-stack developerZeppelin Labs · Banedi
- 2012–2018Software EngineeringORT University, Uruguay
Tools and languages
- Platforms
- Web, iOS, Android
- Back end
- Node, PostgreSQL, tRPC, Drizzle, WebSockets
- Front end
- TypeScript, React, Next.js, React Native (Expo)
- Quality
- Automated tests, CI, Sentry, PostHog
- Graphics
- Three.js, React Three Fiber, GSAP, Canvas
- Languages
- Spanish (native), English (C1), Portuguese (basic)
Work
Tap a record to open its chapter.
Independent2025–now
Orbe
Wellness marketplace
Los amigos de un amigo
Website and ticketing
SweetPark
Parking app for iOS and Android
El juego del celu
A party game for your phones
Zeppelin Labs2018–2025
2025–now · Independent
Client work and products of my own.
Client project · Wellness marketplace
A marketplace for wellness and alternative therapies. You find a facilitator, book a session and have it by video call, right inside Orbe.
In Orbe you get one card a day, with its reading.
What it is
Orbe brings together two kinds of users. Seekers explore practices, find a facilitator and book a session, one-on-one or in a group. Online sessions happen by video call, right inside Orbe. Facilitators set up their profile, services and schedule, and get paid through the platform. The two sides talk through an encrypted chat, and an admin team approves facilitators and handles reports and refunds.
With the client
Built hand in hand with Orbe’s founders. They brought the vision and the community, and I brought the engineering side, deciding what to build first and how to handle payments, privacy and growth. I scoped, quoted and built the platform as the sole engineer. Today I’m Orbe’s CTO.
Responsibilities
- The whole platform as the sole engineer, in a monorepo ready for future native apps.
- Two roles with their own journeys, plus an admin panel, on a typed API.
- Payments with dLocal Go, using split payments and refunds, all through its API.
- Video sessions with Daily, plus chat and group classes with a waitlist that lets you know when a spot opens.
- Field-level encryption for chat messages, journal entries, private notes and documents.
- Automated tests and CI quality checks, error monitoring and product analytics.
- Role
- Full-stack development, CTO
- Client
- Orbe
- Stack
- Next.js 16TypeScripttRPCZodDrizzlePostgreSQLdLocal GoDailyCloudflare R2SentryPostHog
- Status
- Launching soon
- Link
- orbeheal.com ↗
Own project · Website and ticketing
The website of my vinyl DJ duo, where people find the next event and buy their tickets.
A Technics SL-1200 turntable in 3D, the one from the duo’s website, with an orange Los amigos de un amigo record on the platter. The record can be grabbed and moved, and the model’s Start/Stop, 33, 45 and pitch controls work.
Move the record and make it play.
To hear it, turn off silent mode on your phone.
What it is
Los amigos de un amigo is my vinyl DJ duo. We put on parties, listening sessions and other events, and the site is where each one lives. People find the next date, buy a ticket with Mercado Pago and get it by email. Behind it there’s an admin panel to run each event, from the first ticket sold to the list at the door.
Responsibilities
- Full-stack development and design of the whole site.
- Ticket sales with Mercado Pago, with payment webhooks, confirmation emails and a stock control that never oversells an event.
- An admin panel to create events, follow sales, add guests and export the door list.
- Product analytics to see where people drop off before buying.
- Role
- Development and design
- Type
- Own project
- Stack
- Next.js 16TypeScriptReact Three FiberPostgreSQLMercado PagoResendMixpanel
- Status
- Live
Client project · iOS and Android app
SweetPark
An app to hand over your parking spot, in real time, to someone nearby who’s looking for one.
Map of Punta del Este showing the simulated trip.
© OpenStreetMapScreens from the real app. Tap Find a spot.
What it is
A mobile app where drivers leaving a parking spot hand it over to someone looking for one. It matches them by live GPS using H3, Uber’s geospatial index, guides the driver to the spot and handles the payment with an in-app wallet. It starts in Uruguay and is built to work anywhere.
With the client
Built for SweetPark’s founders. The whole technical side is mine, end to end: architecture, the iOS and Android app, the back end, payments and the back office.
Responsibilities
- Real-time matching on H3, the hexagonal grid Uber built for its pricing and dispatch. Each position is stored with its hexagon, so a match only checks the 19 cells around a driver instead of a whole country. Searches stay fast and cheap as the app grows.
- Live positions and a guided handover over WebSockets, with both phones following the same state from the server.
- An in-app wallet with Mercado Pago top-ups and an atomic charge on accept, so two drivers are never charged for the same spot.
- A back office to run operations, plus push notifications.
- Role
- Lead engineer, all technical work
- Client
- SweetPark
- Stack
- ExpoReact NativeFastifyWebSocketsPostgreSQLDrizzleH3Mercado Pago
- Status
- In beta
Own project · Party game for phones
El juegodel celu
A game for a group in the same room, each player on their own phone. Scan the code and draw me.Draw me from your phone.
The wall
A mirror of your phone that shows what you draw on it, live.
Point your phone’s camera at the code and draw me.
What you draw on your phone shows up here, live.
It opens full screen. Once you send it, you’re back here.
What it is
A game for friends in the same room. One phone creates the game, the rest join with a code, and everyone plays rounds of drawing, voting and quick challenges. The server keeps the state of the game, so locking your phone or losing signal doesn’t leave you out.
It’s my own project, coming soon. I’m designing and building it on my own, from the game itself to the servers.
Responsibilities
- Game design, art direction (a scrapbook look) and the iOS and Android app with Expo.
- An authoritative game server with Colyseus that handles rooms and players, and lets anyone who loses signal rejoin right where they left off.
- A shared SDK so each new game plugs into the same rooms, timers and scoring.
- Role
- Creator: development and design
- Type
- Own project
- Stack
- ExpoReact NativeColyseusZustandTypeScript
- Status
- Coming soon
2018–2025
Seven years building products for clients, three as a full-stack developer and four as Engineering Manager. As a manager I led teams and owned the relationship with each client, and I stayed close to the technical decisions.
- Clients
- Weekly meetings to align priorities, turn needs into actionable work, estimate effort and build the roadmap with the PM.
- Process
- Agile ceremonies and the team’s workflow, whether Scrum, Kanban or a custom mix.
- People
- Regular one-on-ones, feedback and support to grow, and a team that clears blockers together.
- Tech
- Technical and architecture decisions, including how to implement AI.
Zeppelin Labs for Envato · Engineering Manager
ImageGen
Envato’s AI image generator. You describe what you need and choose from several images, made by different models.
Each request is spread across several models
Three variations of the selected prompt, each made by a different model, named below it.
What it is
Envato’s AI image generator, part of the Envato subscription. You write a prompt, pick a style and a format, and get several images made by different models. You can vote on them, save favorites, download them or ask for more in the same style. Every prompt goes through a moderation check before anything is generated.
With the client
Zeppelin Labs joined Envato Labs, the team behind Envato’s family of generators for images, music, voice, video and more. Our team worked on several of them, mostly ImageGen and MusicGen. This chapter is about ImageGen.
Responsibilities
- Led the Zeppelin Labs team inside Envato Labs, five people working with a product manager.
- Weekly meetings with Envato to align priorities, estimate and build the roadmap.
- Ran the team’s process and one-on-ones.
- Technical decisions with Envato’s engineers, including how to bring new AI models into the product.
- Role
- Engineering Manager
- Client
- Envato, through Zeppelin Labs
- Team
- 5 people and a PM
- Stack
- Ruby on RailsReactTypeScriptAWS LambdaSQSS3Google Vertex AIAmazon Bedrock
- Status
- Live
Zeppelin Labs for Envato · Engineering Manager
deblank
An AI agent designers could chat with to create color palettes, choose fonts and generate mockups. We built it in 2024, when AI agents were still rare.
Pick a brief and watch the agent work.
Palette
Fonts
Mockup
What it is
Deblank was a design companion built for Envato. Designers chatted with an AI agent that understood their brief and answered with color palettes, font pairings, image collages and mockups. It came out in 2024, when AI agents were still rare, and received an Honorable Mention on Awwwards.
The challenge
Language models in early 2024 had real limits for a product like this. Working around them was the core of the project, and the results were surprising.
Responsibilities
- Engineering Manager of the Zeppelin Labs team that built it with Envato.
- Weekly meetings with Envato to set priorities and plan the roadmap.
- Technical decisions on how the agent worked, at a time with very few references to follow.
- Role
- Engineering Manager
- Client
- Envato, through Zeppelin Labs
- Award
- Awwwards Honorable Mention
- Status
- No longer online
- Link
- awwwards.com ↗
Zeppelin Labs · Engineering Manager
A 3D editor in the browser for DIY builders. You design with real parts and know exactly what to buy.
A 3D frame made of PVC pipes and 3-way elbows, with four legs that come off and snap back into place. Drag to rotate it. The button under the parts list snaps or removes all the legs at once.
Ready to build ✓Drag to rotate · tap a loose pipeWhat it is
A free 3D design app on the web for DIYers. You start with one part and add compatible pipes and fittings from each open connection point. They snap into place, and the editor keeps the parts list, exports it as a PDF and turns it into a cart to buy everything. Designs are saved and shared with a link. Zeppelin Labs built the first version, and then the client continued on their own. Today the product lives on as Crafti.
With the client
The client’s rule was that anyone could use it, from a kid to a grandmother. So usability came first, and the editor had to run smoothly on any phone or computer.
Responsibilities
- Engineering Manager of the team that built the first version, from 2022 to 2023.
- In charge of the technical decisions and of discussing them with the client. Many were about 3D geometry, like how parts connect, rotate and snap together, and how to detect when they collide.
- Performance work so it ran on any phone or computer, with shared, compressed 3D models and fast hit detection.
- Weekly meetings with the client, sprint planning and the roadmaps, which I put together, plus every release from development to production.
- Role
- Engineering Manager
- Client
- Crafty Amigo (now Crafti), through Zeppelin Labs
- Stack
- ReactTypeScriptThree.jsReact Three FiberRecoilFirebaseAlgoliaSentry
- Status
- Live as Crafti
- Link
- crafti.com ↗
Zeppelin Labs · Full-stack developer, then project lead
The first digital neuropsychological assessment for children in Spanish, used by professionals across Latin America.
Assessment #0142 · age 8Waiting for the professional…
Great job!
What it is
A multi-platform tool that helps professionals detect learning difficulties in children aged 4 to 15. The professional runs the assessment from a computer while the child solves the tests on a tablet; scoring is automatic and the report comes out in half the time. More than 34,000 children have been assessed with it. Later, a second product grew out of it. Banedi Maestros is a questionnaire for teachers, who answer about 130 questions about a student (attention, memory, language and more) and get a chart that flags where the child may need support.
Responsibilities
- Full-stack development across the desktop app (Electron), the tablet app (Cordova), the shared React interface and the Node back end.
- Later I took the lead of the project and the relationship with the client.
- Led Banedi Maestros (2022–2023), working directly with the founders. I connected it to the main platform with a secure link for each assessment, and answers stay only in the teacher’s browser to protect the children’s data.
- Role
- Full-stack developer, then project lead
- Client
- Banedi, through Zeppelin Labs
- Stack
- ElectronCordovaReactNode
- Maestros
- Next.jsTypeScriptAnt DesignRecoiljsPDFAzure Functions
- Status
- Live · 34,000+ children assessed
- Link
- banedi.org ↗