Yannis Koula

I build products, not prototypes.

Full-stack and mobile developer, I design complete end-to-end applications: architecture, back-end, interface, AI, deployment. Not a layer that I outsource — the entire chain.

My playground is complexity. A mobile app with 12 communicating modules. A business SaaS with its rules, its payments, and its GDPR compliance. An autonomous system that makes decisions on its own, 24/7, without breaking. When a project has many moving parts, that's where I'm most useful.

What I do concretely:

→ Mobile — React Native (iOS & Android), native 60fps interfaces, offline mode, gamification.

→ Web & back-end — React, Node.js, Python/FastAPI, PostgreSQL, Prisma. Clean APIs and databases that handle load.

→ AI — multi-LLM integration (GPT, Claude, Gemini, Mistral, Grok), multi-agent pipelines, RAG, semantic search. AI as a feature, not a gimmick.

→ Infra & security — Docker, European hosting, native GDPR, authentication, monitoring. Code that goes into production without surprises.

Under the YK Développement brand, I support those who have a clear idea and want someone capable of delivering it in its entirety — from the first sketch to the app in users' hands.

My latest project, Ceryo (ceryo.us), sums up my way of working well: a super-app with 12 modules, 13 mini-games, 5 integrated LLMs, in beta on TestFlight. A product that most people would describe as 'an entire team'. I built it.

If you're looking for a dev capable of handling everything without anything getting lost between layers, let's talk.