About
About Felix Kariuki
I build mobile products and spend a lot of time on the systems behind them — architecture, performance, testing, and how a team ships.
I’ve spent the last six years building mobile products — mostly Android, with a good amount of iOS alongside it. A lot of that work has been taking complicated or aging systems and making them easier to build on: modernizing a codebase, improving startup performance, adding tests that actually run in the pipeline, or changing how a team ships.
Right now I lead mobile engineering at Triply, a travel company, across their B2B and B2C apps. Before the senior role I did most of the Android modernization there — moving the app from Java and XML to Kotlin and Compose — and built the fintech behind their payments: virtual cards, payment links, and multi-currency flows.
I’ve worked across fintech, travel, SaaS, and e-commerce, on both sides of the app store. On the side I build and ship my own iOS products, like WealthAtlas, and small developer tools like TimberIOS. Building things end to end keeps me honest about the whole job, not just the code.
I’m based in Nairobi. If you’re working on something mobile — or trying to make an existing app faster, more reliable, or easier to work on — I’d be glad to talk.
How I work
- Architecture
- I like systems that are easy to change. At Triply I led the move from MVVM to MVI and kept the app modular, which made features cheaper to add and legacy code easier to retire.
- Performance
- I measure before I change anything. Startup benchmarking and Baseline Profiles took Triply’s Android cold-start down 19.6% — the number came from profiling, not a hunch.
- Testing
- Tests belong in the development loop, not bolted on at the end. I’ve set up quality gates that expect coverage before a feature ships, and I lean on TDD to keep the habit sharp.
- Delivery
- I automate the boring parts. CI/CD pipelines that build, test, and release mean engineers spend their time on product work instead of babysitting releases.
- Developer productivity
- Small workflow improvements compound. Bringing AI-assisted development into the team, carefully, lifted our velocity about 15% without lowering the bar on review.
- Leadership
- I lead through the work — technical direction, code review, and coaching. Most of what I know I picked up from other engineers, so I try to pass it on.
What I work with
- Languages
- Kotlin
- Java
- Swift
- Mobile
- Jetpack Compose
- SwiftUI
- XML
- SwiftData
- Combine
- Kotlin Coroutines
- Kotlin Multiplatform
- Architecture
- MVVM
- MVI
- Clean Architecture
- Dependency Injection
- Data
- Room
- SwiftData
- Networking
- REST APIs
- GraphQL
- Retrofit
- Ktor
- Testing
- JUnit
- MockK
- Espresso
- Robolectric
- XCTest
- XCUITest
- Delivery
- GitHub Actions
- CI/CD
- Fastlane
- Firebase App Distribution
- Google Play Console
- App Store Connect
- Tools & Services
- Android Studio
- Xcode
- Git
- Firebase
- Firebase Analytics
- Crashlytics
- RevenueCat
Education
Murang’a University of Technology
BSc, Software Engineering
Google Africa Developer Scholarship
Android Development
Working on something mobile? Let’s talk.
Get in touch