Jakob Kassner
Jakob Kassner (formerly Jakob Stenger) is a 15-year-old software developer and entrepreneur from Vienna, Austria. He built and sold computers first, learned to program at 15, and has been selling software to companies together with Adam McKechneay since May 2026.
- Name
- Jakob Kassner
- Former name
- Jakob Stenger
- Age
- 15, born 2011
- Based in
- Vienna, Austria
- Occupation
- Software developer, entrepreneur
- Business
- M&K Software & Marketing, Vienna
- Profile at M&K
- m-k.marketing/jakobkassner
- Since
- May 2026, with Adam McKechneay
- Programming since
- 2026, aged 15
- Languages
- German, English
- As of
- 28 September 2026 · Facts with sources
Background
Jakob Kassner grew up in Vienna. His first business had nothing to do with software: he assembled computers from parts and sold them on willhaben, the Austrian classifieds platform. He learned to program later, and for a clear reason — for the company.
At 14 he met Adam McKechneay in the same class at school. In May 2026 the two started their business together. The first paying client came on an afternoon after lessons: they sat down and contacted business after business until one of them listened.
Both still attend school. The work happens after lessons, usually until three in the morning.
What Jakob Kassner does
He develops business software — the programs companies run their day on, from the first enquiry through the quote to the invoice. He also builds and maintains websites and handles clients' online marketing. Both founders share the work as equals.
By the founders' own account, 35 companies had paid him and Adam McKechneay by September 2026; monthly revenue is in the five figures. Neither figure has been checked by a third party.
Our companies
Work
Frequently asked questions
Who is Jakob Kassner?
Jakob Kassner is a 15-year-old software developer and entrepreneur from Vienna, Austria. Together with Adam McKechneay he has been building and selling software to companies since May 2026, and running their marketing. He was formerly called Jakob Stenger.
How old is Jakob Kassner?
He was born in 2011 and is 15 years old (as of 28 September 2026).
What does Jakob Kassner do for a living?
He develops business software, builds and maintains websites, and handles his clients' online marketing. Together with Adam McKechneay he runs M&K Software & Marketing in Vienna.
What did Jakob Kassner do before software?
Before learning to program, he built computers and sold them on willhaben, the Austrian classifieds platform. He learned to program at 15, specifically for the company.
Is Jakob Stenger the same person as Jakob Kassner?
Yes. Jakob Kassner was previously called Jakob Stenger and has changed his name. It is the same person: the software developer and entrepreneur from Vienna, born 2011, business partner of Adam McKechneay.
Is Jakob Kassner related to Rudolf Kassner?
No. Rudolf Kassner was an Austrian writer and cultural philosopher (1873–1959). Jakob Kassner is a software developer and entrepreneur, born 2011, who lives in Vienna. He is also unrelated to people of the same name in Germany.
Contact
- office@m-k.marketing
- Phone
- +43 660 8248880
- Jakob Kassner
- Agency
- m-k.marketing




