Daniil K.-Senior Frontend Engineer
Check rate
Experience
Senior Frontend Engineer | Creator
-
- • iOS & iPad eye care mobile application.
- • Technologies: React native, expo, xcode, swift
- • Developed background and in-app native notifications, also taptic and sound feedback on timer.
- • Designed and implemented architecture for mobile app, reached a 100+ downloads
- • Configured and integrated Google AdMob for in-app monetization.
- • Successfully launched the application on the App Store, handling the full release
- • Rule 20-20-20
- • Claude Code, TypeScript, React Native, Expo
Frontend Tech Lead
B2B Marketplace | Lemberg Solutions
- • Startup B2B SaaS marketplace/comparison platform for various providers.
- • Technologies: TypeScript, JavaScript, React.js, Node.js, Next.js, Storyblok, AWS.
- • Led a team of four (front-ends, full-stacks).
- • Hit a project launch with limited budget by translating business requirements into technical solutions, designing system architecture, and establishing development workflows.
- • Developed junior devs via code reviews & pair programming, directly impacting stakeholders satisfaction.
- • Integrated SSG & RSC, for fast & high-quality code.
- • Engineered interactive charts with Chart.js focusing on making it accessible.
- • Additional technologies: Jest, React Testing Library.
- • Improved frontend quality through accessible, well-tested and maintainable implementations.
- • Marketplace, Netherlands, software review and comparison platform.
- • Additional technology: Vercel.
Lead / Senior Frontend Engineer
Dealership platform | Lemberg Solutions
- Dealership platform
- • Private enterprise platform for one of the biggest automotive groups in europe.
- • Technologies: TypeScript, Vue, Nuxt, React, Tailwind CSS, Node.js, Kotlin, OpenSearch, AWS, Docker, PHP/Drupal.
- • Implemented video streaming via HLS for front-end side.
- • Introduced Visual Regression Tests (VRT) based on Playwright for unintended pixel shifts, layout shifts, and rendering bugs.
- • Created a custom Gantt chart library upon base third-party library for particular UI requirements and performance challenges.
- • Responsible for architectural decisions.
- • Added Swagger support enhancing communication across full-stack.
- • Added features for search integration via ElasticSearch/OpenSearch like aggregations.
- • Additional technologies: Cursor, TanStack Query.
- • Implemented Playwright visual tests (VRT), increasing bug detection by 30%.
- • Split components with lazy-loading, improving page load speed by 25%.
- • Organized SSR client/server component rendering, achieving 20% faster page load speed.
- • Implemented RBAC + ABAC and maker-checker flow via UI + BFF layer.
- • Developed a high-interactive, cross-platform SVG Gantt Chart, significantly improving data-heavy visualization rendering time.
Senior Full-stack Engineer
Hotel management system | Lemberg Solutions
- Hotel management system
- • Sass solution for hotels either from 0 to complete solution, along with integration to third-party PMS, and serving embeddable widgets.
- • Technologies: TypeScript, JavaScript, React.js, Material UI, Redux, PHP, WordPress
- • Integrated PayByLink payment.
- • Developed a reservation embedded widget for smaller hotels support, driving additional revenue.
- • Profiling React codebase, improving app security & optimizing rendering
- • Additional technologies: Claude Code, TanStack Query.
- • Integrated PayByLink payment, achieving 20% transaction volume growth.
- • Integrated Agentic GitHub workflow, automating PR creation, review, approve, comments.
Senior Frontend Engineer
Talent Acquisition platform | Lemberg Solutions
- Hiring management platform.
- • Web solution for managing hiring workflows and pipelines with AI integration.
- • Technologies: TypeScript, React.js, RTK-query, Mobx, Java, Spring, PostgreSQL, Neo4j, AWS.
- • Designed and integrated AI chat virtual assistant features with WebSocket, increasing user engagement.
- • Integrated unit testing from scratch, cutting down non-catched errors by 20%
- • Developing and maintaining complex frontend features using React and GraphQL.
- • Contributing to architectural decisions and frontend best practices.
- • Collaborating with backend teams (Java/Spring) to design and integrate APIs.
- • Additional technology: TanStack Query.
- • Led a new candidate pipeline with an AI-powered virtual assistant, reducing manual handling.
- • Modeling REST Api and functional services in Go.
Frontend Engineer
Caspio
- • The AI Platform for Custom Business Applications.
- • Technologies: TypeScript, JavaScript, React.js, NX, C#, .NET, MySQL, AWS, Azure.
- • Develop and maintained scalable frontend features using React.js.
- • Maintained 90%+ unit test coverage, significantly improving frontend reliability and reducing regressions.
- • Enhanced shared component library, improving reusability and consistency across the application.
- • Built a custom i18n utility, enabling translations outside React components and simplifying localization workflows.
- • Additional technologies: Redux, Context API, Storybook, Jest, SQL Server.
- • Implemented an algorithm for billing calculations, excluding hardware limitations.
- • Contributed to real-time WebSocket drag & drop functionality, achieving 10% higher user activity.
- • Low-code platform, USA.
Freelance Full-stack/Frontend Developer
Freelance
- • Technologies: React, Vue, PHP, Laravel, Django, Ruby on Rails, MongoDB, AWS.
- • Responsible for the frontend code in Django.
- • Contributed to developing backend MVC applications (Django and Ruby on Rails)
- • Integrated charts and reports into the system's core functionality, resulting in improved usability and a more comprehensive user experience.
- • Collaborated with cross-functional teams to gather and document requirements for the system's core functionality, resulting in a better understanding of user needs and more effective implementation.
- • Financial application, Ukraine, Frontend Engineer.
- • Web & Desktop finance tracker application.
- • JavaScript, TypeScript, React, Electron.
- • Developed new features for the Electron app, contributing to a 20% increase in daily active feature users.
Industry experience
See where this freelancer has spent most of their professional time.
Experienced in Information Technology, Automotive, Tourism, Banking and Finance, and Healthcare.
Business area experience
See which departments and functions this freelancer has contributed to most.
Experienced in Information Technology and Product Development.
Summary
Senior Front-end Engineer with over 8 years in commercial experience building enterprise and start-up web platforms. Expert in TypeScript, React, Vue, Next.js, Nuxt, and Golang enthusiast. I'm focusing on user experience, scalable architecture, AI integration and contributions across the full-stack development when needed.
Skills
Front-End Development
• Javascript
• Typescript
• React
• Next.Js
• Vue
• Nuxt
• Html5, Css Tailwind Css, Sass, Less
• Accessibility, Responsiveness
Backend & Cloud
• Node.Js
• Golang
• Rest Apis, Graphql
• Aws, Gcp
• Docker
• Ci/Cd
• Serverless
• Firebase
• Vercel
Quality Assurance
• React Testing Library, Enzyme
• Vue Testing Library
• Jest, Eslint, Stylelint, Prettier
• Adr
Ai
• Ai Assistant Developnet
• Ai Agents
• Mcp
Additional Skills
• Claude Code, Cursor
• React Native
• Ruby/Ror, Python
• Postgresql, Mysql, Redis
• Vite
• Pnpm, Yarn, Npm
• Oop, Solid, Git
Languages
Education
Collegium Humanum
Master's degree · Internet Marketing · Warsaw, Poland
University of Customs and Finance
Bachelor's degree · Computer Science · Dnipro, Ukraine
Certifications & licenses
JavaScript fwdays’25
fwdays.com
JavaScript fwdays’24 conference
fwdays.com
JavaScript fwdays’23 conference
fwdays.com
JS Fwdays Europe
fwdays.com
Software Architecture fwdays'22 conference
fwdays.com
JS+React fwdays’22 conference
fwdays.com
AWS IoT: Developing and Deploying an Internet of Things
coursera.org
Software Architecture fwdays'21 conference
fwdays.com
Statistics
Experience
Global experience
Expertise
Qualifications
Profile
Frequently asked questions
Have questions? Find more information here.
Daniil is based in Warsaw, Poland and can operate in on-site, hybrid, and remote work models.
Daniil speaks the following languages: Russian (Native), English (Advanced), Ukrainian (Advanced), Polish (Elementary).
Daniil has at least 10 years of experience. During this time, Daniil has worked in at least 7 different roles and for 7 different companies. The average length of individual experience is 1 year and 5 months. Note that Daniil may not have shared all experience and actually has more experience.
Based on recent experience, Daniil would be well-suited for roles such as: Senior Frontend Engineer | Creator, Frontend Tech Lead, Lead / Senior Frontend Engineer.
Daniil's most recent position is Senior Frontend Engineer | Creator at -.
In recent years, Daniil has worked for -, B2B Marketplace | Lemberg Solutions, Dealership platform | Lemberg Solutions, Hotel management system | Lemberg Solutions, and Talent Acquisition platform | Lemberg Solutions.
Daniil is most experienced in industries like Information Technology, Automotive, and Tourism. Daniil also has some experience in Banking and Finance and Healthcare.
Daniil is most experienced in business areas like Information Technology and Product Development.
Daniil has recently worked in industries like Information Technology, Automotive, and Tourism.
Daniil has recently worked in business areas like Information Technology and Product Development.
Daniil holds a Master in Internet Marketing from Collegium Humanum and a Bachelor in Computer Science from University of Customs and Finance.
Daniil has 8 certificates. Among them, these include: JavaScript fwdays’25, JavaScript fwdays’24 conference, and JavaScript fwdays’23 conference.
Daniil is immediately available full-time for suitable projects.
Daily rate distribution
The rates shown represent the typical market range for freelancers in this position based on recent contracts on our platform.
Average rates for similar positions
Rates are based on recent contracts and do not include FRATCH margin.
The average daily rate is the mean of all daily rates from recent contracts of comparable freelancers on our platform.
The median daily rate is the middle value of all daily rates — half of comparable freelancers charge less, half charge more. Unlike the average, it is barely affected by outliers.
Calculated based on our freelancers’ daily rates as of 20 Sep 2026. Actual rates may vary depending on seniority level, experience, skill specialization, project complexity, and engagement length.
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