Marcel Berger - Apps and beyond
AI builds MVPs. I build stable apps.
Stable means software that ships, scales to real users, survives the AI hype cycle, and stays maintainable when the team grows or shrinks. The hard part isn't writing code — it's making sure the code you wrote still works in six months without you.
20+ years in software engineering. Before going indie: microservice architectures for banks, IAM systems in regulated industries, instant payment platforms, digital transformation in critical infrastructure (KRITIS). Production-first, secure by default, designed to last.
Single owner — development and operations in one person. Clients: native iOS, native macOS, Flutter. Backends: Quarkus, Kafka, PostgreSQL. Infrastructure: multi-environment Kubernetes (dev / test / prod) with ArgoCD GitOps, autoscaling node pools, S3 object storage, Prometheus and Grafana monitoring, encrypted secret pipelines with integrity verification, runbook-driven incident response, and self-built AI ops agents that keep it all running unattended.
My approach: short cycles, written summaries, direct trade-off conversations. No status meetings without a deliverable, no scope without an exit criterion, no rewrites without a real reason.
Author of Solopreneur — The Art of Working Alone — what it takes to build, ship, and operate products without a team. Open-source Claude Code plugins and command-line tooling for Apple platforms.
I don't outsource. I don't subcontract. I don't pitch what I haven't shipped myself.
Conversations in German or English.
marcelrgberger.com · github.com/marcelrgberger · linkedin.com/in/marcel-r-g-berger
Conference Talk — Scoping Call
Free 30-minute scoping call for a conference talk, internal company event, or meetup.
Topics I speak on:
• AI in software development
• App development — native Apple and cross-platform
• Building scalable Kubernetes systems solo
• Indie development and running a solo software business
• Open to suggestion
What I build: marcelrgberger.com
Book: Solopreneur — The Art of Working Alone
This call is for scoping the talk: format, audience, length, date, logistics. The actual talk is delivered as a separate engagement.
—
Honorarium: €2.000 net per delivered talk. Invoice issued after the talk.
Travel, accommodation, and meals are arranged and paid by the booking organization. The 30-minute scoping call itself is free.
Invoiced by Digital Freedom (Berger & Rosenstock GbR).
Imprint · Privacy
- 30m
Consulting Session
One focused hour of consulting — architecture review, code review, technical decision support, or guidance on a concrete problem. Followed by a written summary with recommendations.
Stacks I work in: native iOS (Swift), native macOS, Flutter, Java/JVM, microservice architecture, Kubernetes & GitOps, AI-assisted development workflows.
What I build: marcelrgberger.com
You describe the situation upfront, I prepare, we work through it on the call.
Honest, technical, no pitch.
—
Rate: €350 net per session — includes a written summary with recommendations delivered by e-mail within 3 business days. Invoice after delivery of the summary.
Billing: minimum of the booked slot — more if the session runs longer. Free cancellation up to 24 hours before the start. Cancellations after that, or no-shows, are billed in full.
Invoiced by Digital Freedom (Berger & Rosenstock GbR).
Imprint · Privacy
- 60m
Pair Programming Session
One focused hour of pair programming on a topic you choose.
Stacks I work in: native iOS (Swift), native macOS, Flutter, Java/JVM, Claude Code plugin design, CI/CD with GitHub Actions & ArgoCD.
You share your screen, your repo, your problem. We code together. Live, focused, no slides.
What I build: marcelrgberger.com
Bring a problem. Leave with working code.
—
Rate: €200 net per session. Invoice after the call.
Billing: minimum of the booked slot — more if the session runs longer. Free cancellation up to 24 hours before the start. Cancellations after that, or no-shows, are billed in full.
Invoiced by Digital Freedom (Berger & Rosenstock GbR).
Imprint · Privacy
- 60m
Problem Solver
Stuck on something specific? Bring it. I bring fresh eyes.
A focused 60-minute session on one concrete problem — a slow query, a flaky build, an architecture decision, a tricky bug. You describe it upfront, I prepare, we solve it together on the call.
Stacks I work in: native iOS (Swift), native macOS, Flutter, Java/JVM.
What I build: marcelrgberger.com
Honest, technical, no pitch.
Bring a problem. Leave with a path.
—
Rate: €300 net per session — includes the preparation I do before the call to dig into the problem you describe. Invoice after the session.
Billing: minimum of the booked slot — more if the session runs longer. Free cancellation up to 24 hours before the start. Cancellations after that, or no-shows, are billed in full.
Invoiced by Digital Freedom (Berger & Rosenstock GbR).
Imprint · Privacy
- 60m
- Requires confirmation
1
App Review for Vibe Coders
Built your app with AI tools — and now it's wobbling?
A focused review for vibe coders who shipped fast and need to harden what they built. I go through your code, architecture, and operations. You leave with a clear list of what is brittle, what is missing, what to keep, what to throw away.
Stacks I work in: native iOS (Swift), native macOS, Flutter, Java/JVM.
What I build: marcelrgberger.com
Honest, technical, no pitch.
Bring your code. Leave with a list.
—
Rate: €250 net per session — includes the preparation I do before the call to skim your code and operations. Invoice after the session.
Billing: minimum of the booked slot — more if the session runs longer. Free cancellation up to 24 hours before the start. Cancellations after that, or no-shows, are billed in full.
Invoiced by Digital Freedom (Berger & Rosenstock GbR).
Imprint · Privacy
- 60m
- Requires confirmation
1
Initial Consultation
You have an app idea — but want an honest take before you sink time and money into it?
A focused 30-minute conversation. If your idea is realistic, I'll tell you what it actually takes. If it isn't, I'll tell you that too.
Stacks I work in: native iOS (Swift), native macOS, Flutter, Java/JVM.
What I build: marcelrgberger.com
Honest, technical, no pitch.
Bring your idea. Leave with clarity.
—
Imprint · Privacy
- 30m