I build product and modernize the systems behind it
Independent software engineer, available for freelance work.
I'm Elias, a senior software engineer with 15 years building web platforms for startups and scale-ups. Seven years at SumUp: first modernizing the platform, then leading teams across e-commerce, web, and quality. Full-stack with a frontend bias: TypeScript, Node, Go, React, Next.js, event-driven systems. I'm at my best on the hard, unglamorous work: migrating a monolith, rebuilding a brittle CMS, getting a project back on track when it goes sideways. These days I build mostly with AI. I work agentically every day and care about keeping review trustworthy as more of the code is AI-assisted.
Services
How I can help
Focused engineering work, scoped to what your team actually needs right now.
Build
Ship product. From first release to something that scales.
- Full-stack delivery: TypeScript, Node, Go, React, Next.js
- Zero to first release, with a clear "shipped" scope
- Event-driven systems and API design
- Pragmatic choices over gold-plating
Let's talk about your idea and define what "first version shipped" means for you.
Book a call →Modernize
The turnaround work. I untangle what is slowing your team down.
- Legacy migration: monolith to modular or event-driven
- Rebuilding systems nobody wants to touch
- Performance, stability, and developer velocity
- CMS and platform consolidation
Let's discuss what's brittle, slow, or blocking your roadmap.
Book a call →Strengthen
Quality and AI workflows. Plus leadership, when the problem is bigger than the code.
- Agentic development: adoption, guardrails, review at scale
- Technical and team health audits
- Fractional EM or advisory when the challenge is organizational
Let's shape the right format together.
Book a call →Curriculum Vitae
Experience & Background
A mix of hands-on engineering, leadership, and product thinking...
Independent Software Engineer
- Freelance and contract engineering for startups and scale-ups.
- Focus: platform modernization, event-driven architecture, and full-stack delivery.
- Stack: TypeScript, Node, Go, React, Next.js.
Engineering Manager · Purchase, Website Journey, and Quality at SumUp
Managed 10+ engineers across Purchase, Website, and Quality squads.
- Led the marketing website re-platform to Builder.io across 35+ countries.
- Improved purchasing experience and scaled quality practices and coaching.
- Strengthened collaboration between Website and Lifecycle domains.
- Oversaw delivery of high-impact website migration projects.
Engineering Manager · Purchase, Logistics, and Quality at SumUp
Managed 10+ engineers across Purchase, Logistics, and Quality squads.
- Led integrations with third-party logistics providers.
- Maintained logistics and SAP integrations.
- Improved purchasing experience and scaled quality practices and coaching.
- Focused on e-commerce and logistics integrations.
Engineering Manager · E-Commerce Platform at SumUp
Managed a team of 7 engineers in the E-Commerce domain.
- Implemented event-driven architecture for purchasing systems.
- Owned SumUp’s global card reader purchase experience.
- Rolled out re-platformed solution in 35+ countries; introduced DORA metrics.
- Guided re-org and merger into a unified Purchase team.
Senior Software Engineer · Conversion at SumUp
- Migrated monolith to a modular Go-based platform
- Improved performance and autonomy for marketing teams.
- Built reusable UI components and deployment tooling.
- Mentored engineers across frontend and backend systems.
Senior Software Engineer · Consideration at SumUp
- Built reusable UI components for global use.
- Refactored website content systems
- Increased conversion rates through faster page loads and improved UX.
- Supported marketing experiments through better content tooling.
Software Engineer at ZenMate
I was working as a full-stack engineer on ZenMates (VPN) products and websites.
Software Engineer at Coureon Logistics
Developed frontend apps, e-commerce plugins, and an MVP for a warehouse app.
Co-Founder at betweeen.com
Bootstrapped a communications product from MVP to live platform; full product and engineering ownership.
Freelancer at EK Design & IT
EK Design & IT was my own small company. I built web apps and company tooling; highlight: frontend for soundfluence.com (music collaboration platform).
Education
B.Sc. Computer Science (International Media & Computing)
HTW Berlin · 2013 – 2017
Qualified IT Specialist, System Integration
ITERGO Munich / SPE Siemens · 2007 – 2010
Core Competencies
- Engineering: full-stack delivery, event-driven architecture, system design
- Tech: TypeScript, Node.js, Go, React, Next.js
- Infra: Kubernetes, Kafka, RabbitMQ
- AI-assisted development: agentic workflows, AI in code review and CI/CD
- Leadership: team coaching, hiring, quality culture
Let’s get in touch
Building something new, modernizing a platform, or stuck on a migration you keep postponing? I'm happy to take a look.