Tobias Reinsch | Senior Mobile Product Engineer
Senior Mobile Engineer

Tobias
Reinsch.

Native mobile engineering, built to last.

I architect and build native iOS and Android applications — and write candidly about the tradeoffs, decisions, and real-world constraints that rarely make it into documentation. Based in Dresden, Germany.

Latest Articles

Writing about native mobile architecture, performance, and the tooling choices that make strong product teams faster.

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Feb 28, 2026
Engineering AI Testing

Testing code you didn't write: the trust framework for agentic development

When an agent generates a non-trivial feature quickly, how do you know it's correct? Here's the review and testing framework I use to make generated code production-worthy.

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Feb 24, 2026
Web Astro React

How I kept this blog fast without giving up React

I used to think SSG and rich interactivity were mutually exclusive. Astro's island architecture let me keep most of the site static and add JavaScript only where it earns its keep.

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Feb 14, 2026
iOS SwiftData CoreData

SwiftData in production: where it shines and where it doesn't

SwiftData promised to replace Core Data's boilerplate with a modern Swift API. In production, the tradeoffs become clear around schema evolution, query expressivity, and operational risk.

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Feb 7, 2026
Engineering AI Architecture

Agents don't architect reliably: why system design still matters

AI agents can generate a feature quickly. They still usually can't tell you whether you should build it, where it should live, or how it should fit the system. Here's how I think about the architectural work that remains stubbornly human.

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Jan 19, 2026
iOS DevOps CI/CD

A practical iOS CI/CD setup in 2026: Fastlane, GitLab CI, and what ships well

If you want a production-ready iOS release pipeline with Fastlane and GitLab CI, this is a pragmatic setup that balances control, repeatability, and maintenance cost.

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Jan 5, 2026
Engineering AI Tooling

The feedback loop that changed how I write code

Agentic development tools didn't replace my workflow — they inverted it. I used to spend 80% of my time writing code and 20% reviewing it. Now the ratio is flipped, and my output is better for it.

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About my work.

I'm a senior mobile engineer based in Dresden, Germany. I engineer native iOS and Android applications that hold up under real-world conditions. My work focuses on complex mobile challenges — offline-first workflows, demanding UX requirements, and architectural foundations that allow teams to move fast without cutting corners.

Most of my work lives at the intersection of architecture and product: designing systems that are extensible and understandable, not just technically correct. I've navigated the full spectrum — from greenfield architecture to legacy migrations, from fintech to high-traffic ticketing — and I care deeply about the decisions that determine whether a codebase scales gracefully or becomes a burden.

This site is where I think out loud about mobile engineering. Not tutorials, but honest explorations of the decisions that don't have obvious answers: when to adopt SwiftUI, where TCA breaks down, what agentic development actually changes for mobile teams. If you're building something serious on iOS or Android, there's probably something here worth reading.

Core Focus

  • Swift / SwiftUI
  • Kotlin / Jetpack Compose
  • Mobile Architecture
  • Offline-First Systems
  • React / TypeScript
  • UI/UX Design

"Good software is just clear thinking made executable."

Selected Work.

A few products and systems I've worked on across native mobile, sync-heavy workflows, and product-focused engineering teams.

Wolters Kluwer · 2021

OneClick Scan

Receipt scanning app for accountants and their clients — AI-powered automatic detection and cropping of receipts, built natively for iOS and Android as part of the ADDISON OneClick ecosystem.

SwiftUI Jetpack Compose Computer Vision Fintech

Wolters Kluwer · 2021

ADDISON OneClick

Native iOS and Android development for a professional tax platform used by accountants across Germany. Owned the mobile architecture within a cross-functional squad, translating complex compliance workflows into clean, maintainable mobile experiences.

Swift Kotlin Mobile Architecture Fintech

DMFS · 2014

Webcal Sync

End-to-end ownership of calendar synchronisation for iOS and Android — handling CalDAV, offline-first data integrity, and interoperability edge cases that mainstream calendar apps routinely get wrong.

Android iOS CalDAV Offline-First

Get in touch.

I rarely take on new projects, but if you have a hard problem worth solving — or just want to talk native mobile architecture — let's chat.