Relja B.

Full-Stack & AI Engineer | iOS, Python & LLM-Powered Apps

Founder, full-stack & AI engineer with 12 apps live on the App Store, 4,000+ users, and a Top Rated profile with 100% Job Success. I'm not just a developer for hire. I build, ship, and operate my own AI-powered products end to end, and I bring that same founder-level ownership to every client project. From fintech platforms with real bank connections to AI-powered wellness, health, and productivity apps, I design the user experience, engineer the backend, integrate the AI, implement monetization, and take products all the way to launch, App Store or web. What I bring to your project: ⌁ AI Engineering Production AI, not demos: multi-model systems across OpenAI, Claude, and Gemini with cost-tiered model routing, agent pipelines, and vision, voice, and reasoning features grounded in real user data, engineered for reliability, latency, and cost. ⌁ Full-Stack Development I build the entire system, includth FastAPI and PostgreSQL, as well as Firebase and Supabase for authreal-time synchronization, and server-side logic, plus Next.js hboards. ⌁ iOS & Apple Ecosystem Modern, modular Swift & SwiftUI (rk, Swift Concurrency) withpixel-perfect, first-party-qualiteMotion and AirPods sensor data,FamilyControls and Screen Time APs, Apple Watch, and macOS. ⌁ Fintech & Monetization Experience with Plaid integration2 subscriptions, and RevenueCat paywalls, with secure token manag ⌁ Security-First Engineering Hardened authentication flows, sege, and a clean App Store submission history with zero secuing I've shipped. Clients consistently highlight th • Translate complex product ideasiences. • Deliver quickly without sacrifi • Communicate clearly, set realis ownership of delivery. I approach every engagement as a task executor because I thinkabout your users, conversions, anof care I bring to my ownproducts.