Kateryna

Kateryna Filchenko
Front-End Developer
Kyiv, Ukraine
Telegram: @ekaterinafilchenko
Email: [open contact info](look above in the "contact info" section)
LinkedIn: [open contact info](look above in the "contact info" section)

Introduction
Front-End Developer with over 4 years of professional experience in developing and maintaining
web and mobile applications. Experienced with JavaScript, TypeScript, React.js, Next.js, and
React Native. Skilled in building responsive user interfaces, implementing new features,
integrating services, refactoring existing functionality, and supporting multilingual applications.
Background includes admin interfaces, media-rich products, business management tools, and
payment-related functionality.

Technical Skills:
● Main Technologies: JavaScript, TypeScript, ReactJS, React Native
● Secondary Technologies: NextJS, Webflow
●Architecture: Feature-Sliced Design, Nx monorepo
●State: Redux, Redux Toolkit, MobX, Effector
● CSS Syntaxes and Methodologies: CSS, PostCSS, SCSS, Styled Components, Tailwind,
shadcn/ui, Radix UI, BEM, OOCSS, mobile/desktop first
● Markup: HTML, Handlebars, Twig
● Backend: MongoDB, Firebase, Rehive, NodeJS, Express

Testing and Build Tools:
● Build/Software System: Docker, Webpack, Vite, Nginx

React and JavaScript Libraries:
● React Libraries: React Router, Reactstrap, Antd, MUI, Formik, React Hook Form, Google React
Map, Google OAuth, reCAPTCHA, React Paginate, React Toastify, TanStack Virtual
● JavaScript Libraries: lodash, moment, date-fns, dayjs, Axios, VideoJS, Yup, Zod, SheetJS (xlsx), i18n,
WebSocket

Design and Development Tools:
● Graphics Editors: Adobe Photoshop, Figma, Zeplin, Avocode
● Linters: Eslint, Stylelint, Prettier
● Version Control System: Git (GitHub, GitLab, BitBucket)
● Tools: Postman, Storybook
● Management Systems: Jira, Asana, Trello, ClickUp
● Operational System: Mac OS, Windows

Language: English (Intermediate), Ukrainian (Native), Russian (Fluent)

Experience

42flows.tech – frontend developer
March 2025 – present

Project: Internal ERP for orders, inventory, and customer operations

Responsibilities:
● Defining the base project structure, feature modules, and a shared UI layer.
● Adding new modules.
● Developing reusable data tables with filtering, Excel export, and row virtualization.
● Implementing forms with schema validation and Ukrainian and English localization.
● Estimating tasks and delivering stages on schedule with the client.

Technologies: React, TypeScript, Vite, MobX, Ant Design, Tailwind, shadcn/ui, React Hook Form, Zod,
Yup, Axios, i18next, SheetJS

Project: Production planning and shop-floor execution tool

Responsibilities:
● Forming the core planning business logic at the client's request.
● Building an interactive drag-and-drop scheduler.
● Building virtualized tables for large datasets, with Excel export of filtered results.
● Building multi-level accordion tables with nested detail subtables.
● Keeping shared screen state and form validation consistent across flows.

Technologies: React, TypeScript, Vite, MobX, Ant Design, Tailwind, React Hook Form, Zod, Axios,
TanStack Virtual

Project: Admin panel for cashback and loyalty campaigns

Responsibilities:
● Adding campaign management, member administration, and organization settings.
● Implementing validated forms for campaign setup and access control.
● Building Excel import and export for campaign and report data.
● Adding Ukrainian and English localization.

Technologies: React, TypeScript, Vite, MobX, Tailwind, shadcn/ui, React Hook Form, Zod, Axios,
i18next, SheetJS

Project: Customer account for a parcel delivery service

Responsibilities:
● Building a dynamic data grid with Excel column detection and mapping, autofill, inline editing,
and navigation between invalid cells.
● Adapting layouts for desktop, tablet, and mobile.
● Integrating maps, Google sign-in, captcha, real-time updates, and document printing.
● Adding new functionality and refactoring existing code in the monorepo.
● Extending a shared UI kit and documenting components in Storybook.

Technologies: React, TypeScript, Nx, Vite, Effector, SCSS, Tailwind, Axios, i18next, Storybook, Google
Maps, Google OAuth

Expletech, Ivano-Frankivsk – frontend developer
July 2022 – December 2024

Project: Online classes for playing classical instruments

Responsibilities:
● Adding new features and improvements to current apps.
● Creating new functionality for TWIG using React.
● Integrating the app with Google Maps.
● Improving an existing app to make it work better, be more reliable, and easier to maintain.
● Offering technical help for current functions.
Technologies: ReactJs, VideoJS , Google React Map, Twig, Axios, Bootstrap, React Select, React
Slick, lodash, flatpickr

Project: Marketplace for royalty-free music and sound effects

Responsibilities:
● Refactoring existing functionality.
● Implementing new functionality.
● Analyzing existing issues in the project and addressing shortcomings.
● Implementing cross-browser and responsive design.
● Working on the website's multilingual support and adapting styles for Arabic language.
Technologies: NextJS, Axios, Material UI, React Slick, lodash, wavesurfer.js, React Circular Progressbar,
moment, i18n

Project: Service for preserving memories of deceased loved ones

Responsibilities:
● Worked on the core functionality of the website.
● Handled the logic for uploading video, audio, and image files.
● Implemented drag-and-drop functionality in the project.
● Created an admin version of the site for managing account data.
● Integrated multilingual support for the website.
Technologies: NextJS, TypeScript, Axios, Tailwind, React Slick, i18next, qrcode.react, React DnD,
i18next, Yup

Project: Service for managing and running a business

Responsibilities:
● Migrated functionality from the old version of the project to the new one
● Added new features to the project
● Worked on code refactoring and bug fixing
● Configured statistical data visualization using charts
● Enhanced the project to improve user experience
● Worked on both the admin and user versions of the website
● Ensured the project's proper integration with a custom payment service

● Refactored and extended the custom payment service.
Technologies: ReactJs, NextJS, TypeScript, Redux, Redux Toolkit, Material UI, Axios, react-query,
Formik, moment, flatpickr, chart.js, Yup, React Paginate, React Toastify, React Hook Form

Project: App for managing personal accounts and processing payments

Responsibilities:

● Created screens according to the design
● Added new functionality
● Worked on integrating the payment service into the project
● Implemented payment processing functionality, including QR code scanning
Technologies: React Native, TypeScript, Redux, Redux Toolkit, i18next, React Hook Form, React Native
Vision Camera, Yup, Rehive

TECH-Rubicone, Kharkiv – internship
March 2022 – July 2022
● I added new features to make the existing applications better.
● I provided support and maintenance to ensure that the existing functionality worked smoothly.
● I refactored and optimized the existing applications to make them work faster.
● I developed and designed an admin application to manage system resources efficiently.
Technologies: ReactJs, Redux, Formik, Yup, MUI, Moment

Bank JSC CB "PrivatBank", Kharkiv – Telemarketing call center sales specialist
September 2017 – July 2022

EDUCATION
GoIT - Full Stack Developer
January 2021 - February 2022

University of customs and finance - Master’s degree, Finance and credit
September 2018 - January 2020

University of customs and finance - Bachelor’s degree, Finance and credit
September 2014 - June 2018