I'm Jan (but everybody calls me kober) — a frontend developer with more than 10 years of experience building security-focused software (mostly in banking, where the apps must be friendly but the rules are not 😅).
Although I occasionally build full applications, my main focus is on SDK development — creating secure, reliable building blocks that other developers depend on (and hopefully don’t curse too much).
- Develop and maintain security-focused SDKs
- Occasionally build applications using those SDKs (dogfooding is a lifestyle)
- Lead a small team of developers on a daily basis
- Interview developer candidates and help shape the team
- Communicate with customers and handle technical support for the products I develop
- Manage and maintain CI/CD pipelines across different environments
- iOS
- Android
- Flutter
- React Native, Cordova
- Web (React/CSS/HTML)
- Swift, Kotlin, Typescript
- Java, Objective-C
- C, C++
- Bash (for all those mysterious scripts nobody wants to touch)
- Azure DevOps
- Jenkins
- GitHub Actions
- TeamCity
“Jan once fixed a race condition by just staring at the code until it felt ashamed and corrected itself.
10/10 would let him review my PRs again.”
— Definitely Not a Backend Developer
“Our SDK had 327 issues. Jan touched it once, and suddenly it had only 326 issues. Incredible progress.”
— Senior Architect of Unknown Purpose
“Working with Jan is like having a senior developer, support engineer, and stand-up comedian all in one.
He explains complex things simply, jumps in to help anytime, and somehow keeps the team laughing during production outages.”
— Developer that is no longer working with Jan