On my first day as a programmer at American TelNet, I was taken to Norm's cubicle, and told that this would be my desk. Norm's Sun workstation was still sitting there. I asked where Norm moved, and I was told that he had been let go.
The way it was told to me is that Norm's output had gotten too slow. He was capable, but they needed things to be done more quickly. So, the one person who had most helped me become a programmer is the very same person I ended up replacing.
I internalized something from this that maybe wasn't healthy. I looked at the folks who were as old and older than Norm had been, but still worked there. They were all in management. From that point, I realized that I would strive to get into management before I became too old and slow to be able to work at the required pace.
Norm had been in charge of a multi-user, dial-in BBS. Various small companies would buy blocks of phone numbers from American TelNet, and use the BBS to download the connection minutes, number of calls, etc.
My main role was to field calls from these customer-companies and fix problems when something went wrong. The secondary part of my role was to stablize, and (if I could) speed-up the processing back-end for the system. The overall call volume had nearly doubled since the system was first built, and it was taking more than 12 hours to process all of the call logs, parse them into customer downloadable files, and add call origination details to the data.
The first thing that surprised me was that very little of this had been written in C. Most of it was written in a scripting language called C-shell (which has nothing to do with the C language). The good thing about something written in a scripting language is that each step is easy to isolate and replace separately.
It took me a few months, but I eventually got enough of the back-end replaced with small C language utility programs that I wrote, that it was able to do the nightly processing in under 6 hours. A month after that, and the whole thing was stable enough that nobody called with problems anymore.
My first boss was the person who hired me, the CTO. He was pretty hands off, which for the BBS rewrite (and my skill level) was fine, but as the programmer group grew, I was soon put into one of the UNIX Systems programming groups.