Justin Lanfermann · Software Engineer · Munich

I build software people actually use.

Indie iOS apps, web products, and AI experiments, shipped from Munich.

I'm the developer behind NeatPass, the PDF-to-Wallet app featured by Apple. I study computer science at TUM, tutor CS from intro programming to systems-level courses, and write about what I learn shipping real products.

See what I ship Read the blog

Need an engineer? I take freelance projects

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"Apps We Love" · Apple feature37,500+ NeatPass users400,000+ passes created4.5★ on the App StoreCovered by heise onlineTop 8% · CS @ TUMHead of Software Dev @ TUM.ai

Products

Things I've shipped

Real products with real users, designed, built, and launched solo.

iOS app

NeatPass

PDF to Apple Wallet, fully on-device

Airlines, gyms, and ticket shops send PDFs. Apple Wallet wants passes. NeatPass converts any PDF into a Wallet pass directly on the iPhone, with on-device AI and zero uploads.

Apple featured it in "Apps We Love" and is building the concept into iOS 27 as a system feature. I shipped it first.

Explore NeatPass

Users

37,500+

Real people, every day.

Passes created

400,000+

All generated on-device.

App Store rating

4.5★

From 294 ratings.

Apple feature

Apps We Love

Picked by Apple's editors.

Currently

What I'm up to

Teaching at TUM

CS tutor at TUM, helping 250+ students with everything from intro programming to operating systems and networks.

Leading software at TUM.ai

Head of Software Development at Europe's leading AI student initiative.

Open for freelance

Focused on a few projects at a time: web, iOS, and AI. Remote or on-site in Munich.

Writing build logs

Deep dives and write-ups on systems, AI, and what shipping products actually takes.

Blog

Latest writing

Build logs, deep dives, and the occasional hot take.

Project

Building gbar: GitHub, One Glance Away

How I built a native macOS menu-bar companion for pull requests, issues, CI, notifications, and quick actions, with no backend between the app and GitHub.

15.07.2026

Experience

Every Claim Has to Survive the Room: Presenting at Porsche

What presenting a contrarian on-device AI benchmark to experienced engineers at Porsche taught me about defensible evidence, open discussion, and the IP risk I missed.

Where the Community Comes Home: Two Days With Six Years of TUM.ai

Seventy-seven people, twelve batches, and two days in the Bavarian Alps. The TUM.ai retreat was the first time I met the alumni who turned a 2020 group chat into the thing I help run today.

Let's build something

Freelance projects, collaborations, or a hard problem you want a second opinion on. Based in Munich, working everywhere.

Work with me Email me

P.S. I've hidden easter eggs throughout this site, some obvious, others obscure. This page is no exception. ^^