Titan Juels

I've built financial-grade backend services and production LLM-agent systems for creator-economy SaaS, executive search, and consumer lending.

At ENTROPI.US, I sole-authored FastPay, a creator cash-advance backend and finance dashboard, enforcing ledger correctness through single-writer design, DECIMAL balances, idempotency keys, append-only audit trails, and fail-closed jurisdiction guards. I also shipped live SaaS features including TikTok Pixel tracking, bot defense, referral attribution, and ledger fixes.

As co-founder and backend engineer at Laisy, I built an AI relationship-intelligence workspace for executive recruiters, secured HKUST-HKSTP Co-Ideation funding, and ran paid pilots. I architected an LLM tool-calling backend with parallel structured and vector retrieval, reranking, deduplication, safeguards, and regression evaluations.

I've also delivered HKMA-compliant loan APIs at Rabbit Credit and agentic AI workflows at Cartier. My work spans TypeScript, Python, PostgreSQL, FastAPI, Fastify, Docker, cloud infrastructure, and machine-learning systems.