I had to look up TK Solver. That didn’t exist in 1969. I designed and wrote a Linear Programming package on a 64K machine using PL/1.
I built a relational database, before the concept was proposed by Codd, wrote my own memory-swapping routines before they became part of the operation systems, and wrote retrieval functions to pull the data, all using cards.
It increased the company’s share of the entire market by 20% and ran for 18 years without an upgrade or any other maintenance. I met someone who was still with the company.
It was called a system, then. Now, they are called apps — different hardware, same thing. I changed the term so modern people would know what it was.