Pavlo

PAVLO HOLDA
Senior Frontend Engineer

[відкрити контакти](див. вище в блоці «контактна інформація») | Kremenchuk, Ukraine
LinkedIn | Telegram

SUMMARY
Senior Frontend Engineer with 5 years of experience building complex product UI with React, TypeScript and Next.js.
At xTiles, an all-in-one workspace for notes, tasks and projects with 800,000+ registered users, developed Notion-
style databases, calendars with time blocking, the mobile web version and a Chrome extension. Owned features end
to end, such as time zone support, the calendar and Web Clipper, often proposing ideas and technical solutions, and
worked closely with designers, QA and backend engineers. Actively uses Claude Code for spec-driven development.

KEY SKILLS
• JavaScript • HTML5 • REST API
• TypeScript • CSS3 • WebSocket
• React • SCSS • Node.js
• Next.js • Tailwind CSS • NestJS
• MobX • Git • Figma
• RxJS • Jest (unit testing) • Claude Code
• Redux • Webpack • Claude Design

WORK EXPERIENCE
Senior Frontend Engineer (since 2025, previously Frontend Engineer) 01.2022 - 10.2026
xTiles | Technologies: React, TypeScript, Next.js, MobX, SCSS, Tailwind CSS
• Moved web app features and a shared React UI library into npm packages in small PRs to avoid
duplicating code between the web app and the Chrome extension. The code relied on the app's global
state and services and could not run on its own, so first decoupled it via an integration layer.
• Eliminated a recurring class of time zone bugs, such as wrong dates for users with negative UTC offsets:
moved dates from the deprecated Moment.js to date-fns behind one shared layer that sets the user's
time zone and locale for the whole app, added a time zone picker and a device/profile mismatch
prompt, and an ESLint rule that fails the build on direct date-fns use, with the same rule for AI agents.
• Built one universal Calendar component with week virtualization to replace separate calendars with
duplicated logic in database views and the personal planner. This sped up its integration into other
parts of the product, including time blocking.
• Helped increase MCP connection conversion for Claude and ChatGPT. Built the campaign modal: the
first version closed on an accidental outside click or Esc and never came back, so for the second one
proposed closing it only through an explicit choice in the modal.
• Built the database Timeline view from scratch, a paid feature, with drag-and-drop, resize, virtualization
and pagination; extended other Notion-style views with typed properties, linked records and rollups.
• Built features for the xTiles Web Clipper Chrome extension (10,000+ users, Manifest V3): integrations
with learning management systems (LMS: Canvas, Moodle, D2L, Blackboard) with AI-generated course
projects and Canvas PDF syllabus parsing, YouTube AI actions, Gmail "create task from thread".
• Used Claude Code for feature work, starting from written specs and implementation plans.
Frontend Developer 06.2021 - 11.2021
AlterEGO | Technologies: React.js, Redux, JavaScript, HTML, CSS
• Developed and maintained user interface features for web applications.
EDUCATION
Bachelor's Degree in Internet Technologies 2014 - 2019
Vistula University (Uczelnia Vistula)

LANGUAGES
• English - A2 (Pre-Intermediate)
• Ukrainian - native