@b0rk I can think of :
- the sysadmin/devops : ci, deployment, architecture and deployment of where your code is gonna be deployed, ensures you can access it and that it's usable, etc
- the observability guru : that one person that keeps installing apm, tracer, profiler, centralizing and formatting logs, and removing noisy output from them, etc

They may or may not be the same persona as the tool builder and each other, depending on how you see it :)