Skip to content
TC

Hi, I’mThomasCosialls

Thomas Cosialls

CTO, systems architect and full-stack engineer. Blockchain specialist, AI-native across the stack, and twelve years turning ambiguous product ideas into systems that ship.

Start a conversation

Currently building Tuo, a DeFi protocol that generates yield, scaling Croisée, my bootstrapped mobile app, and shipping AI automation alongside both.

Working with:
  • TypeScript
  • React
  • Next.js
  • Node.js
  • Solidity
  • Foundry
  • Viem
  • PostgreSQL
  • Tauri
  • AWS
  • Ethereum
  • Solana

About

I have spent twelve years on the same problem from three different angles: as the engineer who writes the code, as the architect who decides what the code should be, and as the CTO who is accountable for whether any of it reaches a user.

That range is the point. I have taken products from an empty repository to production and paying customers several times over, which means I have already made most of the expensive mistakes, usually on my own budget rather than someone else’s.

The last five years have been mostly on-chain: token standards, account abstraction, protocol interfaces that move real money, and the review work that has to happen before any of it is deployed. Smart contracts are unforgiving in a way ordinary product work is not, and that discipline has made everything else I build better.

I have worked on several continents and with teams spread across the world, each with its own language, hours and way of doing things. Adapting fast is the skill I trust most, and a distributed, international team is where I do my best work.

The rest is temperament. I start things, I take the risk, and I stay curious about almost everything: give me a problem I have not seen before and I will be three steps into it before the meeting is over. If you are building something ambitious, I would love to hear about it.

By the numbers

  • 12 YEARS

    Shipping production software
  • 10+

    Products founded, led or built
  • 05

    Years working on-chain
Expertise

Systems that survive contact with users

01

Architecture & Systems

Backends built to carry real load rather than to demo. Data models and service boundaries that hold as traffic grows, security and access control designed in from the first commit, and systems that scale out across machines as readily as they scale up on one.

  • Distributed backends
  • Databases at scale
  • Security and access control
  • Horizontal and vertical scaling

02

DeFi & Smart Contracts

Solidity that is written to be reviewed. AMM pool maths that decides whether a protocol survives its first volatile day, token standards and vaults, subgraphs that make on-chain state queryable off it, and the fuzzed Forge suites and audit preparation that turn a working contract into a deployable one.

  • Solidity and Foundry
  • AMMs and liquidity pools
  • Token standards and vaults
  • Account abstraction
  • Subgraphs and on-chain indexing
  • Forge fuzz and invariant suites

03

End-to-End Product

Landing page to dashboard to billing to infrastructure, by one person who holds the whole picture. Most useful in the phase where the product is still changing weekly and handoffs cost more than they save.

  • Full-stack from UI to deploy
  • Design systems
  • Desktop and mobile
  • Payments and billing

04

AI & Automation

Pointing models at the work nobody should be doing by hand. Content pipelines that run on a schedule, coding workflows that shorten the loop between intent and merged code, and the back-office processes of enterprises and smaller teams wired together with n8n and custom code.

  • Content pipelines
  • AI-assisted coding workflows
  • n8n and custom integrations
  • Enterprise and SME process automation
Work

Selected work

Companies I founded, products I built and clients I worked with.

  • 01TuoCTO & lead developer2026 —Crypto-native DeFi yield fund. Three on-chain strategies, hedged exposure and self-custodied vaults.Full-stack / Audit preparation / Event-driven backend / DeFi
  • 02CroiséeFounder2026 —Mobile app for seeing the people who matter to you more often than you currently do. Live on the App Store and Google Play.Full-stack mobile / Payment gateway
    Visit
  • 03FortunaFounder2026 —Offline-first wealth management for macOS and Windows. Local data, no server to trust.Full-stack
    Visit
  • 04MoonWhimAI automation engineer2026Tarot reading site for MoonWhim, a successful e-commerce shop selling tarot necklaces. Increased monthly sales by 5%.AI automation / Full-stack / PostHog analytics
  • 05Metrix FinanceBlockchain engineer2025 — 2026Smart contract development for liquidity management automation on Ethereum and Solana. Integrations across Uniswap, Paraswap, Aerodrome, Raydium and Orca.Smart contracts / Audit preparation / DeFi / Liquidity management
  • 06Etherwave LabsCo-founder2024 —Blockchain agency. R&D for clients, smart contracts and DeFi protocols.DeFi / AI agents / Web3 / Blockchain / Smart contracts
  • 07SpyClubFull-stack web3 developer2024 — 2025Real-time multiplayer Telegram Mini App based on the Codenames board game, with on-chain rewards on Hedera. Onboarded more than 100,000 players.Telegram Mini App / Real-time games / Multiplayer / Blockchain
    Visit
  • 08Ethereum Credit GuildFrontend engineer2023 — 2024Interface for a trust-minimised lending protocol, handling live positions and real collateral. Reached $2M in TVL.DeFi / Full-stack
    Visit
  • 09The Smurf's SocietyFull-stack web3 engineer2022 — 2023Web3 gaming application for the Smurfs licence: wallet connection, network switching, signatures and contract interaction under launch-day load. 3 million transactions on Polygon from more than 80,000 connected wallets.Smart contracts / Web3 / Gaming / NFTs
  • 10MyrorCo-founder & CTO2021 — 2023SaaS that generated premium booking websites for short-term rental hosts, straight from an Airbnb listing. Reached $200 MRR.Full-stack / Automation / Payment gateway
    Visit
  • 11KnockerFounder2020 — 2022SaaS that found small businesses without a website, in seconds, from public data. Reached $1,000 MRR.Automation / Scraping / Full-stack / Payment gateway
    Visit
  • 12RunbnbCo-founder & CTO2017 — 2021SaaS automating operations for short-term rental managers. Built and ran it for four years, leading a team of five developers across Asia.Full-stack / Automation / Reverse engineering / Payment gateway
    Visit

How I work

Ship before perfect. Learn before know. Build before talk. Every system I have been proud of got there by being put in front of real users earlier than was comfortable, and every one I regret was protected from that for too long.

Let'sstartaconversation