Senior Ruby on Rails Performance Engineer

Senior Ruby on Rails developer with 11+ years of experience across fintech, SaaS, e-commerce, and startups. Specializes in performance optimization, having reduced Rails API endpoint response times from 90-120s to 1-2s through measuring, raw SQL, indexing, and background job restructuring. Proficient in external API integrations (Google Maps, Chargebee, WhatsApp via 360dialog, SDB Groep, AFAS), handling complexities like retries, idempotency, webhooks, and partial failures. Experienced with legacy codebases and refactoring without introducing regressions. As Tech Lead at clevergig for 3 years, established code review, bug tracking, and ownership processes. Recent roles include FactCTO, Rail Europe, Fitjourney.ai, Kagi (Crystal backend), and clevergig. For personal interest, he built a Rails app with an ESP32 device to track home power outages, combining backend development with hardware.