Hello, I'm

Konstantin Slabenko

aka Konstantin Kai

Senior Software Engineer & Frontend Team Lead

13+ years building high-traffic B2C applications. Leading teams, architecting solutions, and contributing to open-source. Based in Odesa, Ukraine.

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About

Building the web for over a decade

Frontend Team Lead with 13+ years of experience building high-traffic B2C applications. Led engineering teams of up to 10 developers, driving architectural decisions that reduced build times by 35% and release cycles by 50%. Expert in React, TypeScript, and cross-platform development (React Native, Flutter).


Proven track record of solving complex performance challenges, including building native mobile modules that eliminated critical memory bottlenecks. Passionate about developer experience, mentoring, and contributing to open-source projects.


Recently completed a Master's degree in Software Engineering with focus on ML-based developer productivity prediction using TypeScript code analysis.

Experience

Where I've worked

2020 — Present

Frontend Team Lead

Centro — Creator economy SaaS platform

  • Led a team of up to 10 engineers with 1-on-1s, performance reviews, and roadmap planning
  • Hired and onboarded 5 engineers through technical interviews
  • Reduced build times by 35% through Nx monorepo adoption
  • Cut release cycles by 50% with CI/CD pipeline automation
  • Architected and launched BigWish.com — independent Next.js startup

2018 — 2020

Senior Frontend Engineer

Centro

  • Redesigned core product with feature-based architecture
  • Developed hybrid SSR/CSR rendering solution
  • Built TikTok-inspired media player with virtualized lists

2016 — 2018

Flutter Mobile Engineer

Centro

  • Led cross-platform mobile development for Android and iOS
  • Published open-source Uploadcare library (328+ downloads)

2015 — 2016

React Native Engineer

Centro

  • Created TypeScript typings for Expo (@types/expo) — became foundation for official Expo types
  • Built native file upload modules in Objective-C & Java, solving memory crashes

2013 — 2015

Frontend Engineer

Centro

  • Migrated PHP-based builds to Webpack
  • Implemented real-time video streaming via WebRTC
  • Introduced TypeScript to the organization

2012 — 2013

Earlier Career

PRCode, UATrade

  • Full-stack PHP development, database design
  • Web development with Drupal, Joomla, Bitrix

Skills

Technologies I work with

Languages

TypeScript JavaScript Dart Rust Java Objective-C

Frontend

React Next.js Tailwind CSS Vite Webpack WebRTC

Mobile

React Native Flutter Expo

Infrastructure

Nx CI/CD Git Firebase

Open Source & Projects

Things I've built

BigWish.com ↗

Wishlist and gifting platform. Architected from scratch as sole technical architect.

Next.js TypeScript React

Proto Dart/Flutter Plugins

Rust plugins adding Flutter and Dart toolchain support to moonrepo/proto version manager.

Rust Proto Flutter Plugin ↗ Dart Plugin ↗

@types/expo

TypeScript typings for Expo SDK that became the foundation for Expo's official TypeScript support. Received recognition from Expo team.

TypeScript Expo React Native

StandForUkraine.com ↗

Humanitarian initiative supporting Ukraine. Contributed to development.

React Open Source

Uploadcare Flutter ↗

Open-source library for file uploading via Uploadcare. Published on pub.dev with 328+ downloads.

Dart Flutter pub.dev

Contact

Let's work together

I'm currently open to new opportunities. Whether you have a question or just want to say hi, feel free to reach out!

kai@konstantinkai.dev GitHub LinkedIn