Hi. My name is Jan Brennenstuhl, I live and work in Berlin Germany, where I was born and raised. I am a product-minded software engineer, security enthusiast & clean code artist with a huge interest in interdisciplinary software development and engineering leadership. I am a big fan of cycling sports, coffee & hiking.
I currently work in Berlin as principal engineer, focused on application security and making agentic engineering more secure and efficient. I spent years building and operating identity solutions used by millions of customers — balancing UX and security in high-stakes revenue funnels — and have since moved into the broader AppSec space, where I’m most interested in the intersection of security, usability, and automation.
I’ve worked as software engineer and lead on e-commerce funnels, rule engines, cloud strategies, IAM and SSO solutions, REST APIs, system integrations, technology research, legacy migrations, decommissioning projects and modularizing monolithic systems — various things, mostly in e-commerce and security. I practiced software archaeology more than I set up greenfield web services.
I am an internet standards enthusiast, who values open source software and open formats over custom builds. For me, quality software products are created best by small teams of product-minded engineers with a narrow, well-defined business scope and a clear vision. I’m especially passionate about leading and influencing engineers as well as creating and operating reliable, secure and maintainable software products.
I hold a M.Sc. in Computer Science from the University of Potsdam, where I completed my thesis on “Certificate Management in the Cloud for Authentication in university Environment”. I’ve also studied Media Informatics at the Beuth University of Applied Sciences in Berlin.