koviazin.dev
Mikhail Koviazin

Mikhail Koviazin

Senior Full-Stack Engineer · UTC+8

I build reliable browser automation, web scraping systems and browser extensions, enhanced with AI.

12+ years in software engineering, and most of that time I turn messy, protected web sources into clean, structured data you can trust. If a site needs a real browser, login flows or anti-bot handling, that is exactly my kind of work.

See my workContact me
years in full-stack development
12+
products under daily monitoring (at peak)
5,000,000+
browser extensions built
50+
reliability in production automation
99%+

About me

I'm Mikhail Koviazin, a senior full-stack engineer focused on browser automation, web scraping and browser extensions. I earned my Bachelor's and Master's in Software Engineering at Harbin Institute of Technology in China while already working, starting in my second year, and I've spent 12+ years building production systems for clients in the US, Europe and Asia.

I mostly work where scraping and automation get hard: sites that need a real browser, login and session flows, IP rotation and fingerprint management, anti-bot protection, government sources with no public API. This is the part in-house web developers rarely deal with, and the part I like most.

AI has become a big help in my recent projects, and I use it with discipline. LLM extraction plus deterministic validation for sources too inconsistent for hard-coded parsers; agent workflows that combine browser automation with LLM analysis. Costs stay under control because AI works hardest at development time, so the production path stays fast and cheap at volume.

My core stack is Node.js and TypeScript (Puppeteer, Playwright, Cheerio, Apify) with React on the front end, MongoDB and AWS behind it. Full-stack web and Next.js are a strong second: dashboards, admin panels and APIs around the automation.

Beyond the code: I worked on-site in Shanghai, I speak Chinese at a B1 level, and I'm based in UTC+8, working with clients worldwide. I'm fine working alone or in a team, and I can start on short notice.

{
"name": "Mikhail Koviazin",
"age": 31,
"focus": [
"browser automation",
"web scraping",
"browser extensions",
"AI integration"
],
"specialties": {
"anti_bot": ["IP rotation", "proxy management", "browser fingerprinting", "CAPTCHA solving"],
"extensions": ["Manifest V2/V3", "Chrome / Firefox / Safari / Edge", "iOS + Android WebView", "Web Store publishing"],
"automation": ["Puppeteer", "Playwright", "Cheerio", "Apify SDK"],
"ai": ["Claude API", "OpenAI", "agent workflows", "LLM + deterministic validation"]
},
"education": "MSc Software Engineering, Harbin Institute of Technology",
"languages": ["English (C1)", "Chinese (B1)", "Spanish (A2)", "Russian (native)"]
}

What I do

AI-powered automation and extraction

LLM extraction where sources are too inconsistent for hard-coded parsers, with deterministic validation on top, so the output can be trusted. Costs stay low by design: AI works hardest at development time, so production stays fast and cheap.

  • Driver-license checks against state DMV sites with no public API
  • Agent workflows combining browser automation with LLM analysis
  • Structured data from sources that vary too much for hard-coded parsers

Web scraping at scale

At peak my systems scraped 5,000,000+ products daily across 1,000+ sites. I take the tricky ones: real browser, session and auth flows, anti-bot protection. Some of that data fed coupon auto-apply at checkout, where the answer had to come back in under a second, and it did.

  • Price monitoring across thousands of stores
  • Login flows, IP rotation, fingerprint management
  • Sources with no public API at all
  • Big platforms: Amazon, Google, Instagram, LinkedIn

Browser and RPA automation

I turn slow manual work into reliable jobs that run all day unattended. My record so far: an 8-minute verification flow with constant timeouts, rebuilt down to 60-75 seconds at 99%+ reliability.

  • Government sites and forms with no API, CAPTCHA included
  • Multi-step flows: search, fill, submit, re-check
  • Monitoring and alerting on top of automation

Browser extensions

50+ extensions built since the Manifest V2 days: Chrome, Firefox, Edge and Safari, plus iOS and Android WebView. Sometimes the extension is the whole product, and then I build the backend and admin panel too.

  • Coupon auto-apply used by 30,000+ people
  • Ad blocking on a uBlock engine adapted to Safari (1Blocker)
  • MV2 to MV3 migrations and Chrome Web Store publishing
  • PDF interception and annotation in a custom viewer (PDF.js)

Selected work

FatCoupon

Coupon auto-apply extension + the scraping system behind it. 2019-2023.

Cross-browser extension that finds and applies coupons at checkout across 1,000+ stores, with cashback. 30,000+ users and a 4.8/5 rating. I chose the stack, took it from the first MVP to the version those same users run, and led a team of 3. Around the extension sat several connected products on a shared database: price monitoring for selected products, product and coupon scraping. At peak that set processed 5,000,000+ products daily. I designed and built all of it from scratch myself, with my team on the connectors and mappings.

  • Node.js
  • TypeScript
  • Puppeteer
  • Cheerio
  • Apify SDK
  • MongoDB
  • AWS

Visit project

Saleo: Demo Sync

Real-time content sync for an AI live-demo platform. 2024-2026.

Chrome extension (Manifest V3) that personalizes and controls demo data inside live third-party products, swapping API and WebSocket responses on the fly. I worked on several of its features, and Demo Sync I designed and built from scratch on my own: real-time sync that keeps data-rich personalized demos up to date from master templates. Saleo wrote about it on their blog.

  • React
  • Node.js
  • Manifest V3
  • WebSockets

Visit project

Verifast

Browser automation for real-estate verification. 2026.

Browser automation connectors for a tenant verification product in property management. I refactored the RealPage SPA connector that imitates real user actions, cutting runtime from 7-8 minutes (often hitting the 10-minute timeout) to 60-75 seconds at 99%+ reliability. I re-engineered the ResMan connector and took it to production for the first time. I also built driver-license validation for Florida and Texas against state DMV sites with no public API, including CAPTCHA solving without a headless browser.

  • Node.js
  • TypeScript
  • Playwright
  • Claude API

1Blocker

Safari content blocker. 2021-2023.

Deep refactor and new features in 1Blocker, an ad-blocking extension for Safari on macOS and iOS. I adapted the open-source uBlock engine to Safari, even though Safari does not officially support it, built custom mobile-specific blocking, and wrote targeted scripts to counter YouTube's aggressive anti-ad-block measures. Along the way I reverse-engineered competitor blockers to see what held up and what did not, and integrated the extension with the native iOS app.

  • TypeScript
  • Safari / iOS extensions
  • Manifest V3

Visit project

Experience

2026

Verifast (via Toptal) · AI Agent & Browser Automation Engineer

Verification connectors for property management: RealPage SPA, ResMan, DMV license checks.

2024-2026

Saleo (via Toptal) · Senior Full-Stack / Chrome Extensions Expert

Demo Sync and real-time personalization for an AI live-demo platform.

2024

Numen Capital (via Toptal) · Senior Browser Extension Developer

MV2 to MV3 rewrite, in-extension PDF interception (PDF.js), AI smart tags.

2022-2024

Shady.Club (via Toptal) · Senior Browser Extension Developer

Ethical-fashion ratings extension, brand matching across retail sites, AI image search for similar products.

2021-2023

1Blocker (via Toptal) · Senior Browser Extension Developer

Safari ad blocking on an adapted uBlock engine, iOS and macOS.

2019-2023

FatCoupon (Shanghai) · Senior Full-Stack Developer, Tech Lead

Coupon extension for 1,000+ stores plus a 5M+/day scraping system; team of 3.

2016-2020

Freelance (Upwork) · Full-Stack / Extension Developer

50+ extensions and scraping projects across Amazon, Google, LinkedIn and other platforms.

2014-2016

66Bit (Russia) · Software Developer (C#/.NET)

Ad-network aggregation service; led a team of 2.

Plus shorter engagements via Toptal: pre-submission store reviews, fixes in Safari extensions, in-house browser extensions, real-estate tooling.

Contact

Got a scraping, automation or extension problem? Send me the details. I usually reply within a day, and I can start on short notice.

mikhail.koviazin@gmail.com