We run AI agents inside BauGPT. Here's what it taught us about building them.

Our enterprise onboarding takes 90 minutes. The procurement took 11 weeks.

A construction company with a four-billion-euro annual turnover signed up for BauGPT last quarter. Their procurement process took eleven weeks. The actual onboa...

We process 40,000 WhatsApp messages a week. Here's why we built there.

BauGPT processes 40,000 WhatsApp messages a week. About 40% of them are voice notes. I mention this not to flex on a number. I mention it because it explains ev...

AWS Amplify PR Preview Links in 15 Minutes

AWS Amplify PR Preview Links in 15 Minutes Why this matters Your team opens a frontend PR. The reviewer has to either: - Check out the branch locally (5-10 min...

How I Built a Personal CRM with AI (Because I'm Bad at Remembering People)

I'm bad at keeping track of people. Not in a rude way — I genuinely like meeting people — but after a coffee with someone interesting, I'd forget half the conve...

The App Store Rejection Playbook

We got rejected three times before BauGPT Mobile went live. Not for bad UX. Not for crashes. For policy violations we didn't even know existed. Here's what we l...

How RAG Beats Fine-Tuning for Most Startups

How RAG Beats Fine-Tuning for Most Startups When we first started building BauGPT, I was convinced we needed to fine-tune our own model. I mean, it sounds so c...

The Nightmare of Optimistic UI in Chat Apps (And How We Fixed It at BauGPT)

The Nightmare of Optimistic UI in Chat Apps (And How We Fixed It at BauGPT) Users are spoiled. 🤣 If you click "send" in a chat app and see a loading spinner fo...

Why Your App Needs an Offline Mode (Even in 2026)

Why Your App Needs an Offline Mode (Even in 2026) If you're building a SaaS in 2026, you probably assume everyone has 5G. You assume everyone is always connecte...

The Real Cost of "Free" AI APIs

Everybody's building with AI right now. OpenAI has a free tier. Anthropic gives you credits. Google hands out Gemini API access like candy at a conference. So y...

Why I Chose React Native Over Flutter for BauGPT

Why I Chose React Native Over Flutter for BauGPT I get asked this question at every startup event. "Why React Native? Flutter is faster." Here's the honest answ...

The 24/7 Autonomous Shipping System (And How I Built It)

I deployed 40+ TestFlight builds in a single week while I was at a team offsite in Munich. I barely touched my laptop. That's not an exaggeration — I was in mee...

German Construction Has No APIs. So We Built Our Own.

The German construction industry moves about 400 billion euros a year. You'd think there would be APIs for everything. Building permits, material specs, complia...

I Built SSO From Scratch on BauGPT Mobile. Here's Why It Took 3 Days.

I spent 3 days on Sign in with Apple. Apple controls the device. The user is already logged in. Just press a button. Should've been an afternoon. The Setup Buil...

How I Stopped Bot Spam Without Requiring Login

Every indie app gets hammered by bots eventually. Sond — the trip planning app — hit this around month 2. Suddenly 40% of new accounts were fake. They'd load th...

How a WhatsApp Bot Brought 1000 Test Users to Sond in 3 Weeks

Everyone says the same thing about indie launches: "Get on Twitter. Product Hunt will make or break you. Hacker News is where developers hang out." All true. Al...

Why AI Doesn't Work for Most Startups (And How to Fix It)

"We added AI to our product!" crickets I see this pattern everywhere. Startup adds ChatGPT API. Slaps "AI-powered" on the landing page. Waits for users to care....

How We Solved the €500M Language Barrier Problem in German Construction

What Is an AI Growth Engineer? (And Why You Need One)

I get asked this question a lot: "What exactly is an AI Growth Engineer?" Fair question. The role didn't exist 18 months ago. Here's what it actually means — an...