About

I’m Constantin — a software engineer in Erfurt, Germany, with over ten years building backend systems and integrations, mostly where business systems meet engineering: Salesforce/Apex, Ruby/Rails, TypeScript, and the LLM/MCP tooling now running through them. I’m currently a senior engineer at On in Berlin.

What I do

Most requests arrive vague, from someone non-technical. My work is to find the real constraint, turn it into something we can build, ship it, and keep it running. I stay close to both the business side and the technical detail, so engineering and operations end up working from the same plan. Ten years across different stacks has made me pick tools by fit and prefer solutions the people using them can maintain without me.

At HEC Paris

I’m also doing an MSc in Innovation & Entrepreneurship at HEC Paris, where I lead my team’s project: using changes in a system’s third-party dependencies as an early warning for outages. It’s where I think in products and business cases rather than only implementations.

Before On, I worked on Salesforce and Clojure at JustOn, full-stack web and integrations at tolingo, and Ruby/Rails earlier on. The full timeline’s in my CV.

Quick facts

• Based in Erfurt, Germany — remote / hybrid, EU-wide
• Experience 10+ years building software — full-stack, backend, integrations
• Stacks TypeScript, Ruby/Rails, Salesforce/Apex — plus what a problem needs
• Also Docker, AWS, CI/CD, LLM-assisted development, and Model Context Protocol tooling
• Interested in applied AI in production workflows, technical leadership, solutions architecture, and product-minded engineering
• Languages English, German, Ukrainian, Russian, Polish, basic French
• Certified Salesforce Platform Developer I & II

Get in touch

Easiest is [email protected] (ProtonMail — ask for the key if you want to encrypt). I’m also on LinkedIn and GitHub. Hiring, building something, or just want to talk? Say hi.