Stefan Kirsch
Co-Founder CTO / Head of Engineering, federly.com
Serial CTO and startup founder who transforms technical visions into scalable realities. Stefan built and led engineering teams of 40+ people at multiple companies, from B2B FinTech to global platforms serving hundreds of thousands of users. Currently running ResuFit (AI-powered recruitment tools) while serving as Interim CTO for digital transformation projects across diverse sectors. His rare combination of physics-trained problem-solving, hands-on technical depth across multiple languages (TypeScript, Python, Java, C++, Go), and proven track record of building high-performance engineering cultures from scratch makes him the kind of technical co-founder who doesn't just write code—he architects the future. What sets Stefan apart: he's successfully navigated the exact journey federly.com is embarking on, from technical individual contributor to scaling CTO to equity-focused founder. Having worked across security-critical industries including banking, automotive, and insurance, he understands both the technical complexity and business imperatives that make identity and authentication systems mission-critical. This isn't his first rodeo building something from zero—it's his specialty.
Interim CTO - Senior VP Engineering
digital rapids GmbH · Hamburg
- Spearheaded strategic technology transformations across 3+ diverse industry sectors, driving innovation and technological modernization
- Provided executive-level technical leadership as interim CTO for multiple high-growth technology clients, delivering critical strategic guidance
- Conducted comprehensive technical assessments for 6+ M&A projects, evaluating technological assets, infrastructure, and scalability risks
- Enabled 20%+ operational efficiency improvements through targeted technological interventions and strategic technology roadmaps
Co-Founder
ResuFit · Berlin, Germany
- Co-founded AI-powered job seeker toolkit startup, applying extensive tech-hiring experience to solve recruitment challenges
- Built and launched ResuFit.com platform, demonstrating end-to-end product development and go-to-market execution
- Leveraged deep understanding of AI product development to create innovative solutions in the recruitment technology space
Tech Owner Buy & Fulfil
Peek & Cloppenburg KG · Düsseldorf
- Led 40+ member team developing omnichannel checkout and fulfillment technology stack and architecture
- Orchestrated creation of carve-out organization to consolidate all software engineering within the group
- Spearheaded replacement of 1,000+ legacy POS cash desk systems with modern re-implementation using current hardware and UI libraries
- Drove Site Reliability Engineering chapter as Head of SRE while introducing modern hiring and agile development practices
- Served as strategic liaison between group HR, company leadership, and technical teams for cross-organizational initiatives
CTO & Co-Founder
Arbour GmbH · Berlin
- Defined and executed strategic technical direction for B2B FinTech company, building initial product from concept to launch
- Recruited and led first engineering team, establishing state-of-the-art engineering practices and development culture
- Conducted customer interviews to inform technical roadmap planning and product-market fit validation
- Established security-focused engineering practices essential for financial services compliance and customer trust
CTO & Managing Director
Kialo GmbH · Munich - Berlin
- Built platform for thoughtful discourse reaching hundreds of thousands of active users, handling all operational matters as managing director
- Led software engineering department while contributing to product roadmap and setting technical architecture for massive scale
- Globally recruited and managed diverse team of nearly 40 engineers plus additional remote team of 15
- Constructed 4 Full Stack Engineering development teams, QA testing and automation team, SRE team, and administrative teams
- Developed comprehensive career framework establishing culture of open feedback, ownership, and technical excellence
- Successfully relocated company operations from Munich to Berlin while maintaining team cohesion and productivity
Principal Consultant
TNG Technology Consulting GmbH · Munich
- Delivered high-end consulting services across automotive, telecommunications, insurance, banking, and publishing sectors
- Performed hands-on development, technical team leadership, architecture design, and due diligence analysis
- Introduced and coached agile practices across diverse company settings, demonstrating adaptability to various corporate cultures
- Built deep expertise in security-critical environments through work with banking and insurance clients
Software Engineer Intern
SiemensVDO AG
- Developed OEM navigation systems for major global car manufacturers, working on map creation backend and embedded systems
- Built transformation pipeline from raw satellite mapping data to customer DVD using Java, Oracle, and C++
- Improved standard K-D Tree algorithm with custom tiling algorithm, later patented by Siemens
- Served as official Siemens representative in industry initiative to standardize map data formats across suppliers
- Collaborated on creating fully standardized, interchangeable next-generation map format for OTA customer delivery
Dipl.-Phys. (Physics)
Physics
University of Regensburg
- Completed thesis at chair for high temperature superconductors: 'Efficient routing calculation by applying physical optimization procedures'
- Applied physics algorithms to computer science problems including AI and continuous optimization
- Specialized in optimization of industrial processes and computational physics applications
Custom Tiling Algorithm Patent