Senior Backend Engineer
Barcelona, Spain
Senior backend engineer, ~8 years, shipping distributed systems in Go, TypeScript, and Python. Four years at the blockchain protocol boundary - lead backend at Pingpay (crypto-native checkout and onramp on NEAR Intents, 200+ assets). Previously led agentic R&D at Hubmaker and built a multi-tenant rec-engine in Go. AI-native engineering with Claude Code and Cursor daily.
Salary
GBP 80,000 – 140,000
Pingpay
Nov 2025 — Present
Own the distributed backend for a crypto-native commerce product. Microservices on TypeScript/Node.js; live swap execution across NEAR Intents DEX; multi-deploys per day; observability-first production ops. Built the onramp combining Coinbase Onramp with NEAR Intents DEX API, expanding asset support from <10 to 200+ tokens. Shipping a Rust-in-TEE subscription product on Phala Network. Delivered a Stripe-like merchant dashboard with full transaction history, CSV exports, and audit tooling.
Hubmaker Labs
Oct 2023 — Oct 2025
Led agentic R&D on Koki, an agentic social networking assistant. Architected agent orchestration prototype, instrumented success and retention metrics. Led the pivot of Shonen into a multi-tenant distributed API backend in Go - recommendation-engine-as-a-service with Postgres + pgvector. Managed delivery quality, release cadence, and funding-milestone alignment across contractors and FTEs in Europe and the US.
Harmonic Guild
Apr 2023 — Present
Co-founded a technology collective focused on distributed and open-source ecosystems. Delivered SDK development, distributed application architecture, and digital infrastructure for clients in Europe and the US. Built and maintained open-source developer tools and libraries. Technical writing, workshops, and mentorship.
Zbyte
Oct 2021 — Apr 2023
Early engineer on an enterprise distributed application platform. Built the platform's first enterprise wallet with end-to-end key management, signing flows, and enterprise UX. First hands-on exposure to custodial wallet primitives at production scale. Promoted to Product Manager: owned pricing strategy, go-to-market planning, and enterprise sales calls.
Barclays
Aug 2018 — Oct 2021
Global Payments Hub SDET ensuring reliability, correctness, and regulatory compliance of mission-critical payment systems under FCA/PRA envelope. Zero prod regressions on owned modules across 3-year tenure. Transitioned into ML engineering: deployed models to production and built Python 3 APIs for model consumption under strict financial compliance.
B.Tech · Information Technology
2014 – 2018