Story time! I Worked with not just a "rockstar" but what I suspect was a "superstar" for about three years at my last gig. It was a small company with about 3-4 developers at any given time and we worked on an embedded Linux product in a moderately safety-critical industry that had a messy ~25 y/o codebase and a custom, roll-your-own Linux distro on custom hardware. Our "superstar" had been with the company for ~10 years and due to really high turnover I was the most senior of the rest of the staff with 3 years. The manager of the software team claimed to have 10+ years of software development experience on his resume and LinkedIn, but would ask CS 101 questions in our software planning meetings.

The basic workflow adopted by our manager was thus:

  1. Discover a bug or get a feature request
  2. Pass the task to the development team verbally
  3. Developers prioritize tasks based on which ones are more likely to be forgotten by management
  4. Approx 20% of tasks get completed
  5. Repeat step 1

Basically our superstar developer absolutely allowed our non-technical management to commit software development seppuku. His successes were highly visible, but his failures were not:

  1. Clobbering other developer's commits because he didn't know how to use git to rebase or merge changes
  2. Copy pasting (not forking) entire codebases to work on a new feature that then got so bloated they were impossible to merge
  3. Absolutely no documentation of any sort, not even comments.
  4. No automated testing of any sort on any of his code even though there was an effort by the rest of the team to do better testing.
  5. Refusal to use the common Docker development platform everyone else had standardized on, many times his code only worked on his machine.
  6. He wouldn't fix bugs, he would just re-write the core logic of the feature that had the bug and then he wouldn't bother to remove the old logic.
  7. Regular, daily code dumps of 1000-2000 LOC that contained new features that were not discussed by the team, sometimes from casual conversations with a sales person, sometimes completely made up by him out of boredom I guess.
  8. Our Linux BSP was stuck in Amber because the only copy of it was on his local machine (allegedly). When asked many many times by the rest of the team to get it in our company repo he would check in something that did not compile and was not even remotely close to what was being used on our boards.
  9. Instead of adding dependencies where needed he would take a 3rd party library, chop it up and copy-paste it into our code directly (see point 8).
  10. Last but not least just general slop code with 15-20 levels of indentation, no modularity, dirty hacks everywhere.