Startup CTO for funded startups in Germany

What a startup CTO answers for after a funding round

After a seed or Series A round a startup’s technology has two audiences: the customers who use the product and the investors who paid for the next step. The CTO answers to both. When no founder holds the position, or the founder who held it moves to product or sales, the startup brings in a CTO from outside, for a period or permanently.

Finance, real estate, e-commerce: where the technology risk sits

Each of the three sectors carries a risk of its own, and a CTO plans for it from the first release. The table lists the ones I have met, with the work where I met them. Your product may carry others.

Sector and risk	What the technology needs	Where I met it
Finance: a bank’s compliance review stops the contract	Documented calculation methods, and terms that hold legally	Terms, price definitions, manifest and API methodologies of a market data product, 2023
Finance: prices arrive late or wrong	Real-time delivery and a check that flags deviating values	Market data over WebSocket and RPC, with an outlier detection, 2022
Insurance: the product has to fit an insurer’s or a partner’s systems	Interfaces to the CRM and to partner products	A digital insurance manager connected to an existing CRM, in which customers order products of external partners
Real estate: one property appears as several records	One identity per object, versions, register codes as a shared key	My research on object identity
Real estate: users search large data sets	A search index in front of the database	Elasticsearch over millions of real estate records, with answers within milliseconds
E-commerce: customers leave between cart and payment	Short order funnels, the payment methods customers expect, mobile pages	Order funnels with PayPal, WorldPay and Amazon Pay for shops of Lidl and REWE, 2011 to 2016

My roles in these sectors, newest first

• Since April 2026: AI engineer in a client’s platform transformation, where Claude and Codex work under rules that bind agents and people alike.
• 2022 to October 2024: Head of Decentralized Finance and Node Operations, then Chief Information Officer from January 2023, at the Frankfurt-based company Blocksize Capital. Details: CIO and Head of DeFi at a Frankfurt fintech.
• 2017 to January 2024: editor in chief of an information portal on construction projects, with more than one million readers a year by 2024.
• 2016 to December 2021: Project Manager and Web Developer at Policen Direkt, in the German secondary market for life insurance.
• 2011 to 2016: Project Lead and Developer at Valentins (Burda Digital), with shops for Lidl and REWE and their conversion optimization. Details: Experienced in conversion optimization.
• 2004 to 2010: Managing Director and CTO of a company that built a global real estate database. KfW and the venture capital investor Neuhaus Partners invested several million euros in it. Details: A global real estate database.

Who I am

I am Michael Wutzke, and I live in Frankfurt. I hold a training authorization from IHK Frankfurt. At Claude Hacker House I teach prompting, AI-assisted workflows and MCP servers. I build software with Claude and Codex, and I am interested in open-source AI models that a company runs on its own servers. I work in German and English. Details: Career stages.