Frontend Developer at LiveDune

Owned key onboarding and plan-purchase flows, later handled repeat payments and retention end to end. Designed and built a configurable analytics dashboard builder and an auto-reply module, including API contract and frontend architecture; these modules are used by 30% of active customers. Led migration to TypeScript (40% of codebase typed) and improved state management by moving to Zustand for client state and React Query for server state. Introduced frontend A/B testing using GrowthBook and integrated with Yandex Metrica, running experimentation from hypothesis to metric results. Rewrote billing to move plan logic off the frontend, enabling robust in-plan upgrades, currency selection, and custom handling for failed payments with CloudPayments and Stripe. Improved onboarding performance by removing 13 redundant requests and 209 KB data, shortening the critical rendering path.

Frontend Developer at ProOption

Worked on a real-time trading interface with WebSocket quote streaming and order execution. Owned the real-time UI part, the UI kit, and build/testing infrastructure. Shipped an interface in four languages across desktop and mobile. Implemented and optimized real-time price charts where performance and data accuracy were critical. Built a Styled Components + Storybook UI kit with documentation and test coverage shared across repositories. Migrated the build from Webpack to Vite with custom plugins, reducing production bundle size by 15%. Set up automated testing (Jest, React Testing Library, Cypress) and error logging with Rollbar, and ensured tests were blocking in CI. Created technical documentation from scratch (architecture, domain logic, technologies, development processes).