Javier Cervilla

Javier Cervilla

Senior full stack and Blockchain engineer from Madrid, Spain
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I build production-grade web apps and blockchain products end to end: architecture, backend, frontend and deployment. Ex-founder and CTO, so I care about your business goals, not just the...

  • Architecture
  • Database Administration
  • Devops Engineering
  • Data Analytics
  • Back-end Development
  • Front-end Development
  • Full Stack Development
  • Mobile Design
  • UX/UI Design
  • Web Development
  • Web Design
  • Crypto Development
  • Smart Contract Development
  • Software Dev, Data & Web - Other

I build production-grade web apps and blockchain products end to end: architecture, backend, frontend and deployment. Ex-founder and CTO, so I care about your business goals, not just the tickets.
For the past 5+ years I co-founded and led engineering at Universelle, a web3 product studio in Madrid, where I shipped products used by thousands of people:
Rarestamp.xyz, the first marketplace for Bitcoin Stamps (React, TypeScript, Node.js, PostgreSQL)
One of the first Bitcoin Stamps indexers, turning raw Bitcoin transactions into near-real-time public APIs
SRCPad, a launchpad and DEX on the Internet Computer built with Rust/Motoko canisters and ckBTC
Solidity smart contracts, audits and full-stack dApps for client projects
What I can help you with:
Full-stack web apps and APIs: TypeScript, Node.js/Deno, React, PostgreSQL/MongoDB, Docker, CI/CD
Smart contracts and dApps on EVM chains (Solidity), Bitcoin (Stamps, SRC-20, UTXO indexing) and ICP (Rust, Motoko, ckBTC)
Blockchain indexers, data pipelines and high-throughput backends
Technical leadership for early-stage teams: MVP scoping, architecture, code review
How I work: clear scope up front, short iterations with working demos, and proactive communication, no surprises. I trained at 42 Madrid (first cohort) and have won several hackathons along the way.
Based in Madrid (CET), fluent in English and Spanish, open to fixed-scope projects and ongoing engagements. Tell me what you're building and I'll come back with a concrete plan.