Nairobi, Kenya
Felix Kariuki
Senior Mobile Engineer
I build and lead mobile products — Android and iOS — with a focus on architecture, performance, and the engineering systems teams rely on to ship.
Selected impact
A few results I can point to
Three outcomes from the current work at Triply — each measured, with the work behind it.
19.6%
Reduction in Android cold-start time
Introduced startup benchmarking and Baseline Profiles at Triply, then measured the result.
40%
Faster feature delivery
After migrating Triply’s Android app from legacy Java and XML to Kotlin and Jetpack Compose.
15%
Higher developer velocity
From bringing AI-assisted workflows into the team’s day-to-day — without lowering the bar on review.
Featured
A few things worth seeing first
Products I’ve shipped and work I’m proud of.
iOS App · Product
WealthAtlas
Personal-finance app for tracking net worth across currencies and asset types, with AI-powered insights.
Engineering · Case Study
Triply
Mobile platform modernization, fintech capabilities, performance, and delivery systems for a travel company.
Open Source · Swift
TimberIOS
Lightweight structured logging framework built on Apple’s Unified Logging System (OSLog).
Projects
Also on GitHub
Beyond the products above — a selection of open-source apps and libraries.
Open Source · Kotlin Multiplatform
Kotlin Multiplatform · Compose
FreeToGame
A Kotlin Multiplatform app for Android, iOS, Desktop, and Wear OS with a shared Compose UI.
Open Source · Android
Kotlin · Clean Architecture · TDD
DevSpace
Built with Clean Architecture and TDD, consuming the GitHub, WakaTime, and Programmer Quotes APIs.
Open Source · Kotlin Multiplatform
Kotlin Multiplatform · SQLDelight
KmmCaching
Shared networking and offline caching across iOS and Android with Kotlin Multiplatform and SQLDelight.
Open Source · Android
Kotlin · Jetpack Compose
Open Source · Android
Kotlin · Room · MVVM
Experience
Six years, mostly close to the code
Android first, iOS throughout — across fintech, travel, SaaS, and e-commerce.
Dec 2025 — Present
Current
Triply.co
Senior Mobile Engineer
I lead mobile engineering across Triply’s B2B and B2C apps — setting technical direction and keeping the platform fast, maintainable, and shippable.
Feb 2023 — Dec 2025
Triply.co
Android Engineer
I did the bulk of Triply’s Android modernization — moving a legacy Java/XML app to Kotlin and Compose — and built the fintech behind travel payments.
Aug 2022 — Apr 2023
Adanian Labs
Android Engineer
I led Android for a farm-management platform — a marketplace plus payments for agricultural businesses — and contributed to the iOS app.
Apr 2022 — Oct 2022
Brainverse Technologies
Android Developer
I built customer-facing fintech and e-commerce apps, and spent a lot of time on reliability.
Jun 2021 — Feb 2022
Machini Technologies
Android Developer
My first engineering role — modernizing a legacy Java app and wiring up mobile payments.
How I work
Engineering, in practice
Not philosophy — the things I actually spend time on, tied to real 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.
About
A bit about me
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.
Contact
Have a role, project, or engineering problem worth talking about?
The fastest way to reach me is email. I read everything and reply to most.