Nursultan Bergeliev

Designed and built the In Vitro laboratory medical registration front-end for a medical diagnostics company with ~30,000 users and ~260,000 tests daily. Implemented Feature-Sliced Design (FSD) with dedicated slices for entities, types, UI, and API integration. Delivered core modules including patient registration, lab latest order management, appointment scheduling, search, and medical record viewing. Integrated REST APIs (patient data, service catalog, scheduling, order data, test composition) and wrote unit/snapshot/integration tests using Jest, Testing Library, and supporting tooling. Improved front-end performance via lazy loading and code splitting, reducing load times by up to ~30%. Set up code quality (ESLint, Stylelint, Prettier), built UI layouts from Figma mockups, and optimized registration workflow and tab navigation. Conducted code reviews and mentored junior developers to strengthen team practices and continuous improvement.

Worked on CMS for major streaming service (Wink/Rostelecom): implemented performance optimizations (memoization, lazy loading, code splitting), built complex validated forms with drafts support, and migrated from Webpack to Vite. Reduced page load times from ~4–5 seconds to ~2 seconds through component splitting and reducers. Implemented a smart date-range input with format prediction to reduce data entry time and improve UX.

Built an Interview Scheduler for internal corporate calls (Avito). Developed FullCalendar-based UI with React, created drag-and-drop interview slots using DnD Kit/core, and implemented multi-level debouncing search and participant assignment (interviewer + candidate/employee) and notice functionality. Delivered an MVP accepted by the client with full functional coverage.