I build mobile products that scale — from MVPs for early-stage startups to enterprise architecture in regulated industries. 5+ years of Flutter, since version 1.0. 10,000+ developers trained.
Maximilian Berktold
Architect · Fractional CTO
Trusted by teams at
Selected stops from 5+ years of architecture, engineering and leadership work.
Who I am
I'm Maximilian Berktold. I build, lead and teach Flutter — and I ship my own products. That combination is rare: someone who writes the code, leads the team, gets the investor pitch, and has been on stage for years explaining how to do mobile right.
I've been working with Flutter since the very first releases. Started at Siemens Energy with C++, then made Flutter my craft. Today I'm an external architect at VisualVest in Frankfurt, building a multi-tenant white-label investment platform — and running my own ventures in parallel.
What you get when we work together: someone who makes architecture decisions with business consequences. Someone who doesn't just close tickets, but takes ownership. Someone who understands why your investor needs to see that demo in four weeks — and how to ship it without burning the codebase.
Maximilian
Founder · OpenSphere Software
Currently
Architect @ VisualVest · Frankfurt
By the numbers
What I do
I work in three clearly separated profiles — depending on your product stage. Need none of these? Then we're probably not a fit.
You have an idea, funding and a deadline? I build the product — architecture from day one, clean code, App Store ready. No hack that eats you in six months.
Your app is growing, the team is growing, and nobody wants to look at the code anymore? I take over architecture, define standards, refactor legacy and lead your team — as external lead or sparring partner.
Regulated industry, high standards, no internal mobile lead? I take technical responsibility for your mobile stack — strategy, hiring support, architecture governance, FinTech security.
How we work together
I work remote, invoice monthly, write nothing into dark rooms. Here are the five ways we can set this up.
Project basis · greenfield
For whom · Startups with funding and a deadline
One-off audit · 2 weeks
For whom · Teams who want to know where they actually stand
Add-on · regulated industries
For whom · FinTech · HealthTech · public sector
Retainer · strategic leadership
For whom · Scale-ups without an internal senior lead
Retainer · hands-on in code
For whom · Teams that need a senior in the trench
All rates net. Travel, license and cloud costs on top. Minimum engagement: 2 weeks.
Send me a short note about what you're building and where you stand. I'll get back within 24 hours with an honest take.
Selected work
A cross-section of FinTech, public sector and consumer apps. Click any project for details.
Click a project to enlarge · ESC to close
Built by me
I don't just build for others. These products are mine — as founder or co-founder. That's exactly why I understand what you're going through.
Event and social platform with an Eventim partnership for European rollout. Flutter app, Next.js web, backend, infra — all built end-to-end.
Training intelligence for ambitious athletes. Data-driven coaching, wearable integration, performance tracking.
Biohacker platform around peptides, hormones and performance. Community, knowledge base, product sourcing.
Franchise concept for 24/7 gyms. Site search Bamberg & surroundings — with self-built tech backbone.
Authority
Talk on Flutter architecture and mobile scaling.
10,000+ students · 40+ hours of video · bestseller status on Udemy.
Published on Amazon. A hands-on book for junior freelancers.
Tailored Flutter trainings for company teams across Germany.
Frequently asked
Solo. You work directly with me — no account manager, no junior, no outsourcing. If your project needs more hands, I build a reliable team around me.
8 to 14 weeks, depending on scope. I'll be upfront with you about what's realistic — and what you should not pack into V1.
Remote by default. On-site workshops, kickoffs or architecture sessions absolutely possible — DACH and EU.
My core is Flutter & Dart. Backend I do with Next.js, Supabase and Firebase. Native iOS/Android I read, but don't write primarily.
MVP builds start at €20,000. Audits from €4,900. Retainers from €98/h. After our intro call I'll send you a clear offer with scope, timeline and fixed-price options.
Three reasons: you talk directly to the person writing the code. You get someone who founded companies himself and understands business. And you don't pay an agency margin on top of a junior dev.
Pledge
A share of our revenue goes to Phoenix Shelter, an animal rescue that urgently needs support.
“Animals can't speak up for themselves. We do — and you can too. Every contribution helps.”
External link · Donation goes straight to the rescue
Let's talk
Tell me what you have in mind — even if it's still an idea. I'll respond within 24 hours with an honest take on whether I can help or not.
Prefer async? Send me your brief, deadline and budget by mail. Saves us both time.
Phone
+49 176 42013486