Ask HN: Whats the best internal tool where you work?

I’m extremely guilty of being obsessed with internal tools.

I have worked with internal dashboards written in php which could predict the expected sales of the day, admin servers that could manage jobs and deployed software fleets across all servers and chatbots that could run software maintenances end-to-end.

Some software was so good that I felt the pain of it when leaving.

Does anyone have any tools like that?