Eren Mutlu

I've built payment, reservation, and banking systems across ASP.NET Core microservices, .NET, and Node.js. At Calibre Tour, I develop a B2B/B2C travel booking platform spanning hotels, flights, transfers, and packages.

I built its pricing and booking flows around a multi-currency double-entry ledger, idempotent saga transactions, live FX rates, and integrations with bank acquirers, Paycell, and IBAN top-ups. I also reduced search latency by about 50% through Redis caching, N+1 elimination, and PostgreSQL indexing.

Previously, I led backend work at Pawbooking.co, managed five engineers, and brought a pet-accommodation booking engine to production. I've also delivered warehouse microservices, a custom .NET SSR engine in the Netherlands, and high-throughput corporate banking microservices using Kafka and Redis.

I'm the author of LIBRAIN, an open-source multi-agent RAG system that ingests arXiv papers and generates citation-grounded scientific hypotheses using .NET, Qdrant, Semantic Kernel, Anthropic Claude, and OpenAI.