8 years building native and cross-platform mobile applications (iOS and Android) across fintech, crypto, logistics, and public security.
Shipped all 4 payment rails (card, Apple Pay, Google Pay, BLIK) into an Expo banking app by building a custom native Expo module wrapping Checkout.com SDKs (~60% native Swift/Kotlin). Removed ~30% duplicated code across 3 company projects into reusable libraries (API client, money-precision arithmetic, design tokens). Established OpenAPI codegen pipeline reducing endpoint integration from hours to minutes. Built team's entire CI/CD pipeline: quality gates, test runs with reporting, AI-assisted code/security review, and namespace-aware module publishing.
TypeScript monorepo (pnpm + Turborepo) powering a real-time tow truck dispatch platform spanning manager web, driver web, dispatcher web, and React Native (Expo) apps — built as founding engineer authoring ~74% of commits. Built contract-first API layer auto-generating 130+ typed models from OpenAPI spec. WebSocket-powered live maps with optimized event batching enable dispatchers to track and assign jobs in real time. Multi-tenant RBAC (driver, dispatcher, manager, owner) supports independent company accounts from a single deployment with background GPS tracking for positioning accuracy on low-end devices.
Blockchain-native social network and NFT marketplace on Velas chain reaching 10K daily active users. Built C++→native bridge for Telegram messaging via TDLib (CMake compilation to dynamic libraries, native interface with JS callbacks, ~75% native C++/Swift/Java work). Powered on-chain trading/royalties/lotteries across 3 blockchains via 5 smart-contract integrations (ERC-20/721/1155, escrow-based royalty contract, subscription contract). Shipped self-custody crypto wallet and staking web app with strict TDD. Eliminated scroll jank (15→60 FPS) using RecyclerListView item sizing optimization. Standardized icon usage with type-safe Icon component (Strategy pattern).
Cross-platform agricultural management app (React Native + Next.js) for farmers and field agents in developing economies — where most users operate without reliable internet. Built offline-first functionality for ~70% of the app using local storage (MMKV), offline optimistic updates, and persisted query queue replayed on reconnect. Sustained stability across a large monorepo where multiple apps shared modules by raising test coverage to ~90% (Jest) to catch side-effect regressions during feature work.
Native Android fitness tracking engine for Africa's largest fitness event platform. Built a persistent Headless.js background service that continuously reads device sensors (accelerometer, gyroscope) and combines real-time motion data with user biometrics — age, height, weight — to calculate burned calories, active time, and classify the current activity type (walking, running, cycling, etc.). All results are streamed live to the React Native layer with the screen off, keeping the tracker fully operational in the background without draining battery unnecessarily.
Production mobile banking app for First Bank of Nigeria, one of the largest banks on the African continent. Contributed to core banking features — account management, money transfers, bill payments, and transaction history — alongside offline USSD support for customers in low-connectivity regions. Also built a native Acquire SDK bridge for PCI-compliant card payment and identity verification flows.
Web and mobile platform for music producers and artists to distribute tracks and analyse global reach. Worked across the full product as a React / React Native developer inside a monorepo, shipping features for both web and mobile simultaneously. Built an interactive world map using SVG and React Native Reanimated that lets producers and artists visualise the geographic spread of their plays and records in real time — animating per-country statistics as users explore the map. Covered business logic with Jest unit tests throughout.
Open to senior remote contracts in mobile and front-end engineering. Available across EEA and US time zones.
d.bohatyrchuk@gmail.com →