Siarhei L.

I help clients improve existing native iOS and Android apps, integrate new features, and prepare releases. My Upwork work history includes Swift and Kotlin development, BLE wearable integrations, HealthKit, subscriptions, AI feature integration, Stripe, and Mapbox. For an existing app, I start by reviewing the codebase and reproducing the main issue, then agree on a focused first milestone with clear acceptance criteria. I lead Sparkler Soft and clarify my own responsibilities and any team involvement before work begins. Share your current stack, main blocker, and target release date so we can define the next step.