As an applied mathematician, Steffen started his career in 2000 in the automotive industry as a method- and software developer for mathematical and simulation software, with a particular focus on applications using mathematical optimization, numerical simulation, and artificial intelligence.

Since 2017, he has been working to implement blockchain technology for real-world applications. He has developed applications with industry partners and products in IoT, energy, mobility, sharing economy, asset management, and self-sovereign identity.

2021 Steffen co-founded with 3 partners corpus as a venture studio for web3 applications. Now Steffen is focused on web3 messaging as one of the venture studio's successful projects. He and his team are developing dm3, the web3 messaging protocol for secure and interoperable communication.