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Serhii Kuznetsov

Front-End Developer · Cherkasy, Ukraine

I build web apps
that ship.

I'm Serhii Kuznetsov, a front-end developer working in React, Next.js and TypeScript. Lately that has meant a dashboard that filters ten million rows in the browser, a multiplayer whiteboard with its own sync engine, and a full-stack cooking product with AI recipe import and its own mobile app.

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Serhii Kuznetsov, Front-End Developer
Open to work
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Years of experience

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Projects on this site

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Written-up case studies

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Technologies across them

Selected work

Things I've built

All 14 projects
Data Visualization2026

Strata — Crossfilter over Millions of Rows

Linked charts over up to ten million rows, all in the browser: brush any chart and every other one follows within the frame.

  • React
  • TypeScript
  • Web Workers
  • WebGL2
  • Cloudflare Workers
Case study Live
Real-time2026

Tessera — Multiplayer Whiteboard

A shared canvas with live cursors, offline edits that merge on reconnect and per-person undo — with the sync written from scratch.

  • React
  • TypeScript
  • Canvas 2D
  • Cloudflare Workers
  • Durable Objects
Case study Live
Full-Stack Product2025 — now

Cook Galaxy — Recipe & Meal-Planning App

A full-stack cooking product with AI import, meal plans, subscriptions and a companion mobile app.

  • Next.js
  • TypeScript
  • Prisma
  • PostgreSQL
  • Tailwind CSS
Case study LivePrivate repo
  • Next.js
  • React
  • TypeScript
  • Tailwind CSS
  • Framer Motion
  • Prisma
  • PostgreSQL
  • three.js
  • React Three Fiber
  • Zustand
  • TanStack Query
  • GraphQL
  • Vitest
  • Playwright
  • Expo
  • Git

Notes

Bugs worth writing down

All notes

  1. 5 min read

    Two windows, one client id

    A shared whiteboard where one window's edits reached nobody. The protocol was right and its tests were green — the browser had copied something I had assumed belonged to a single tab.

    • Realtime
    • Browser storage
    • Debugging

  2. 5 min read

    The refusal that named nothing

    A change the room threw away stayed queued for ever: its author kept seeing an edit no one else had. Fixing it was less about the limits than about what a refusal has to carry.

    • Realtime
    • Protocol design
    • Testing

  3. 4 min read

    The lag my test browser could not see

    Headless Chrome draws at 60 fps whatever the monitor. On a 165 Hz screen that hid a 146 ms frame — and the CSS property behind it was one I had decided was free.

    • Performance
    • CSS
    • Measuring

What's next

Looking for someone to build the front end properly?

I'm open to full-time and freelance work. Tell me what you're building and I'll tell you honestly whether I'm the right person for it.

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