I build complex software for businesses that can't afford to get it wrong.

I'm Konstantin. Former product leader at N26 and Urban Sports Club. Payments. GDPR. Data isolation. Multi-tenant platforms. The stuff most developers avoid. You focus on your business. I'll build the infrastructure.

About

I build software for businesses where security, compliance, and data integrity aren't optional—they're the product.

Former product leader at N26 and Urban Sports Club, where I drove growth and operational efficiency through data-driven product development. At N26, I reduced payment-related fraud by 92%, saving over €2.2M annually within 4 months.

Now I build custom platforms for businesses with complex technical requirements—from GDPR-compliant data architectures to multi-tenant SaaS, from concept to shipped product in weeks.

Recent work spans healthcare platforms, legal-tech infrastructure, and practitioner management systems—all domains where getting it wrong has real consequences.

My background spans early-stage startups to major European tech brands. I combine hands-on technical execution with strategic product thinking—and I take on the work most developers avoid.

Recent Work

Kaufmann Health – Therapy Marketplace Platform

Operational marketplace connecting patients with body-oriented psychotherapists in Germany. Built and running the full stack solo: automated matching, Cal.com booking integration, GDPR-compliant data architecture, Google Ads acquisition with optimized conversion funnels, and Stripe payment infrastructure.

Growing therapist network with verified credentialing pipeline, multi-tier practitioner model, and automated lead nurturing. Stack: Next.js, Supabase, Cal.com, Stripe, Resend, Google Ads API.

Health Practitioner Digitization

Online course platform and digital infrastructure for an independent health practitioner, combining technical implementation with project management for clients who need both execution and guidance.

Work

Head of Academy

Jul 2023 - Nov 2024

Built and led a 12-month Product Management certification program from curriculum design to operations.
Recruited and managed 14 coaches and a Customer Success team, serving 150+ students across 10+ courses.

Lead Product Manager

May 2022 - Feb 2023

Built and launched an EDI integration (ISO standard) for supermarket-to-supplier order communication—hardcore B2B infrastructure with legacy system constraints.
Drove technical integration with enterprise partners while managing product roadmap, recruiting, and engineering team operations.

Lead Product Manager — Payments, Platform & Site Reliability

Apr 2020 - Apr 2022

Owned payments, partner payouts, finance, and compliance across two brands. Reduced payment-related fraud by over 92%, saving €2.2M annually.
Led the Platform tribe: migrated core infrastructure from AWS to Google Cloud, introduced microservices, and upgraded legacy frameworks (including a PHP version no longer receiving security updates) used by 6+ engineering teams.
Oversaw Site Reliability Engineering. When money was missing or transactions didn't reconcile, my team investigated and resolved it.

Co-Founder

Jun 2019 - Feb 2020

Built an ordering platform for restaurants sourcing from small-scale local suppliers. Global Top 25 in the Pioneer Tournament (Marc Andreessen, Patrick Collison, Stephen Wolfram).

Product Owner — Cards & Payments

Apr 2017 - Apr 2019

Promoted four times in two years—from Customer Service to Product Owner leading three payments teams and managing card infrastructure for 3M+ users.
Launched Apple Pay and Google Pay across 10+ European markets. Enabled UK and US expansion by making card processing multi-currency. Ensured PSD2 and GDPR compliance.
Managed major production incidents with direct customer impact. Grew team from 3 to 14. Worked directly with Google, Mastercard, and card processing partners.

Contact

Let's build your next product

If you need a custom product or digital infrastructure but don't have an in-house engineering team, choose how you'd like to start the conversation.

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