Hello, I'm

Fabian Gröger

Senior Software Engineer & Solution Architect

From UIKit to Kotlin Multiplatform: 9+ years of shipping apps — now designing reusable building kits that turn business requirements into scalable software.

Portrait of Fabian Gröger

About

I've spent 9+ years writing production app code — from UIKit through SwiftUI to Kotlin Multiplatform — and leading the teams around it. Now I'm stepping into the architect seat: designing the reusable foundations that keep many projects consistent.

Most of that time was at CHECK24, Germany's leading comparison portal: health insurance and Profis apps in Hamburg, shopping and travel in Düsseldorf — first on iOS, later on Android as well, and from 2022 leading a team of 10. Wherever I worked, the CI/CD pipelines were mine too: automation is how a small team ships like a big one.

At ABUS I build a kit of multiplatform libraries — Kotlin Multiplatform with Compose — so every project draws from the same consistent, reusable code. From 2027, as Solution Architect, I oversee all projects, match them against the building kit, and transform business requirements into scalable software solutions.

Based near Siegen, Germany, working in German and English. Off-screen: video games, family, and sports.

What I Do

Nine-plus years of app development, distilled into five focus areas.

01

iOS Development

From UIKit to SwiftUI — 9+ years of native iOS.

Started with UIKit at CHECK24 in 2017 and made the move to SwiftUI as it matured. Shipped production features in health insurance, craftsman services (Profis), shopping, and travel apps used by millions.

  • Swift
  • UIKit
  • SwiftUI

02

Android Development

Kotlin and Java on the shopping and travel side.

Extended the CHECK24 Düsseldorf stack from iOS to Android, working across both platforms on the same products. Today Android knowledge flows mostly into cross-platform work with Kotlin.

  • Kotlin
  • Java
  • Android SDK

03

Kotlin Multiplatform & Compose

One codebase, consistent UI across platforms.

Current main focus at ABUS: a building kit of multiplatform libraries that keeps code consistent and reusable across projects and platforms, with Compose Multiplatform for shared UI.

  • Kotlin Multiplatform
  • Compose Multiplatform
  • Shared Libraries

04

CI/CD & Automation

Pipelines at every station of my career.

Built and maintained CI/CD pipelines throughout my career — from Bamboo in the early days to Jenkins and Ansible today, with Fastlane automating mobile releases. Automation is how a small team ships like a big one.

  • Jenkins
  • Ansible
  • Fastlane
  • Bamboo

05

Agentic Engineering

Building with AI agents, not just about them.

Exploring how AI agents change the engineering workflow — from agent-assisted coding to automated pipelines — and applying it day to day. This portfolio itself was built in an agentic workflow.

  • AI Agents
  • LLM Tooling
  • Automation

Skills

Languages

  • Swift
  • Kotlin
  • Java

Mobile & Cross-Platform

  • UIKit
  • SwiftUI
  • Jetpack Compose
  • Compose Multiplatform
  • Kotlin Multiplatform

CI/CD & Automation

  • Jenkins
  • Ansible
  • Fastlane
  • Bamboo

Practices

  • Solution Architecture
  • Team Leadership
  • Agentic Engineering
  • Agile

Career

  1. 2025 — Present

    Software Engineer → Solution Architect (2027)

    ABUS August Bremicker Söhne KG

    Building a kit of multiplatform libraries that keeps code consistent and reusable across projects and platforms; from 2027 as Solution Architect overseeing all projects and transforming business requirements into scalable software solutions.

  2. Apr 2022 — Mar 2025

    Team Lead App Development

    CHECK24, Düsseldorf

    Led a team of 10 across the shopping and travel apps, worked on Android alongside iOS, and kept the CI/CD pipelines running.

  3. Apr 2021 — Mar 2022

    App Developer

    CHECK24, Düsseldorf

    iOS and later Android development on the shopping and travel apps, with CI/CD pipeline work.

  4. Jul 2017 — Mar 2021

    App Developer

    CHECK24, Hamburg

    iOS development for the health insurance app and CHECK24 Profis, plus CI/CD pipelines.

Contact

Open to senior engineering and architecture conversations — roles, consulting, or a good technical debate over coffee.