Although to be fair most simulation code I've come across was written by Physics majors who really shouldn't be writing code. Most of those implementations are a crime against engineering and humanity alike.
They do the job, though, and I suppose crimes against engineering are better than crimes against physics, if one had to choose.
Software engineers*. Computer scientists are concerned with the math behind computing and are mostly found in academia. Software engineers generally have a foundational knowledge of computer science they combine with software engineering principles to create robust software. Generally software engineers do have computer science degrees though.
They share a similar relationship as engineers and physicists.