Chris Krueger

Portfolio

MindTime

Health

Android

iOS

A simple and pure meditation timer for daily practice consistency. Highly customizable with internal interval bells, session tracking, and mindful insights.

Momental

Health

Android

iOS

A meditation and sleep sounds app with customizable soundscapes, timers, and habit tracking. Designed to help you fall asleep faster and build a mindful routine.

ReSubs

Finance

Android

iOS

Track and manage all your recurring subscriptions in one place. Get reminders before renewals, spot unused services, and keep your spending under control.

Moviebase

Entertainment

Android

Never lose track of your TV shows and movies. Browse the largest movie database, manage your watchlist, and discover what to watch next.

StreamGuide

Entertainment

Android

Find what to watch across your streaming services. Discover new releases, compare ratings, and stop wasting time scrolling through catalogs.

Work Experience

1. 

   KAYAK

   Sep 2021 — May 2025

   Berlin

   Software Architect — Android

   Mar 2024 — May 2025

   • Rebuilt foundational components in Jetpack Compose, establishing patterns adopted across the Android team
   • Shipped front-door and search filter components under tight release deadlines
   • Built custom Gradle plugins and instrumented analytics across all search verticals

   Compose

   Architecture

   Gradle

   Tech leadership

   Senior Android Engineer

   Sep 2021 — Feb 2024

   • Modularized the Android app: +140% modules, 18% faster builds
   • Architected unit-test infrastructure that lifted test coverage by 71%
   • Led Iris Flights API integration and the Flights redesign launch

   Kotlin

   Modularization

   Testing

   Design systems
2. 

   Invia Group

   Mar 2018 — Aug 2021

   Berlin

   Lead Mobile Engineer

   Mar 2021 — Aug 2021

   • Led the Android and iOS teams architecting the fluege.de booking apps
   • Refactored parts of the iOS app using SwiftUI, ViewModels, and reactive streams

   Team leadership

   SwiftUI

   Architecture

   Senior Android Engineer

   Apr 2019 — Feb 2021

   • Cut Android and iOS data + business logic by 50% by adopting Kotlin Multiplatform
   • Educated the iOS team on Kotlin and brought both platforms onto a shared development flow
   • Reduced the bug backlog 30% with TDD and a real unit-test culture

   Kotlin Multiplatform

   Coroutines

   TDD

   Android Engineer

   Mar 2018 — Mar 2019

   • Built and shipped the fluege.de Android app from scratch with the team
   • Introduced clean architecture: modularization, dependency injection, MVVM

   Kotlin

   Clean architecture

   Gradle
3. 

   LucaNet AG

   Nov 2013 — Jul 2017

   Berlin

   Java Software Engineer

   Apr 2015 — Jul 2017

   • Built new features in the LucaNet IDE — a Java client for consolidated financial statements
   • Maintained and tested the existing platform and owned its technical documentation

   Java

   Agile

   Software Engineer

   Nov 2013 — Mar 2015

   • Built interfaces between ERP systems and the LucaNet Data Warehouse with Java and SQL
   • Designed Data Warehouse solutions and rolled them out on-site at customers

   Java

   SQL

   Data warehousing
4. 

   PROMATIS

   Oct 2010 — Sep 2013

   Karlsruhe

   Software Engineer

   Oct 2010 — Sep 2013

   • Designed and built a Java client for generating e-balance sheets
   • Implemented PL/SQL interfaces against the Oracle ERP system

   Java

   Oracle

   PL/SQL

Frequently Asked

What kind of apps do you build?

Small, well-crafted mobile apps focused on real, recurring problems — subscription tracking (ReSubs), meditation and sleep (Momental, MindTime), and watchlist discovery (Moviebase, StreamGuide). The bar is high user experience over feature bloat. Shipped on Android, with iOS versions for the core lineup.

What kinds of opportunities are you open to?

Contract, consulting, and advisory work around Android, Kotlin Multiplatform, and mobile architecture. Senior IC and architect roles. Podcasts, interviews, and speaking on mobile, KMP, and indie development. Paid research, surveys, and indie collaborations. If it's interesting, send it over.

What's your tech stack?

Kotlin and Jetpack Compose on Android, Swift and SwiftUI on iOS, and Kotlin Multiplatform for shared business logic. Plus Gradle, modular architecture, dependency injection (Koin), and a strong testing culture built on TDD and CI.

What's the best way to reach you?

Email is best for anything substantive — use the envelope icon at the top of this page. For shorter conversations, X (Twitter), Bluesky, and LinkedIn all work. Replies usually within a few days.

Where are you based?

Berlin, Germany. I work remotely and on-site across Europe.