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Senior Front-End Developer with 7+ years of commercial experience building scalable web applications and driving performance improvements. Experienced across the full development lifecycle (architecture, implementation, testing, and migration from Webpack to Vite), with strong mentoring and code quality practices. Built large-scale medical/diagnostic platforms serving tens of thousands of users daily, applying Feature-Sliced Design (FSD), API integration, and testing. Deep expertise in React/Next.js/TypeScript, UI optimization (lazy loading, code splitting), and modern tooling with a focus on maintainability and user experience.…Senior Front-End Developer with 7+ years of commercial experience building scalable web applications and driving performance improvements. Experienced across the full development lifecycle (architecture, implementation, testing, and migration from Webpack to Vite), with strong mentoring and code quality practices. Built large-scale medical/diagnostic platforms serving tens of thousands of users daily, applying Feature-Sliced Design (FSD), API integration, and testing. Deep expertise in React/Next.js/TypeScript, UI optimization (lazy loading, code splitting), and modern tooling with a focus on maintainability and user experience.

Nursultan Bergeliev

Front-End Developer, Web Developer, Web Designer, +2

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Senior Front-End Developer with 7+ years of commercial experience building scalable web applications and driving performance improvements. Experienced across the full development lifecycle (architecture, implementation, testing, and migration from Webpack to Vite), with strong mentoring and code quality practices. Built large-scale medical/diagnostic platforms serving tens of thousands of users daily, applying Feature-Sliced Design (FSD), API integration, and testing. Deep expertise in React/Next.js/TypeScript, UI optimization (lazy loading, code splitting), and modern tooling with a focus on maintainability and user experience.…Senior Front-End Developer with 7+ years of commercial experience building scalable web applications and driving performance improvements. Experienced across the full development lifecycle (architecture, implementation, testing, and migration from Webpack to Vite), with strong mentoring and code quality practices. Built large-scale medical/diagnostic platforms serving tens of thousands of users daily, applying Feature-Sliced Design (FSD), API integration, and testing. Deep expertise in React/Next.js/TypeScript, UI optimization (lazy loading, code splitting), and modern tooling with a focus on maintainability and user experience.

Available to hire

Senior Front-End Developer with 7+ years of commercial experience building scalable web applications and driving performance improvements. Experienced across the full development lifecycle (architecture, implementation, testing, and migration from Webpack to Vite), with strong mentoring and code quality practices.

Built large-scale medical/diagnostic platforms serving tens of thousands of users daily, applying Feature-Sliced Design (FSD), API integration, and testing. Deep expertise in React/Next.js/TypeScript, UI optimization (lazy loading, code splitting), and modern tooling with a focus on maintainability and user experience.

Skills

Experience Level

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Intermediate

Language

English

Advanced

Russian

Fluent

Work Experience

Senior Front-End Developer at Zebrain

February 20, 2022 - May 1, 2026

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.

Front-End Developer at Andersen

December 20, 2020 - December 20, 2021

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.

Senior Front-End Developer

December 1, 2020 - December 1, 2021

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.

Web Developer

September 1, 2019 - December 31, 2020

Developed CMS for industrial equipment capacity planning (Siemens) in a European client environment based in Germany. Built complex UI components such as tables with drag-and-drop and lazy loading. Optimized web graphics with WebP integration and SVG sprites. Participated in English team calls and delivered responsive engineered device pages and an application redesign that improved document loading speed.

PHP Developer (Custom PHP templates / Backend work)

January 1, 2019 - Present

Customized PHP templates (XSLT/TPL), created HTML templates for client needs, installed them into the CMS, and maintained a SaaS solution.

Web Developer (Freelance)

August 1, 2018 - August 1, 2019

Created page layouts from templates; integrated templates into WordPress and 1C-Bitrix. Worked on backend tasks with PHP/XSLT/TPL and maintained a SaaS solution.