The cost of repetition
A meaningful share of engineering time goes to work that is necessary but not interesting: writing tests, updating documentation, checking assets against conventions, tracking down a regression's origin.
Mercury is an internal platform aimed at that work specifically, on the basis that time recovered from it is time spent on the parts of the product players actually experience.
Analysis and detection
Static analysis tuned to the studio's own conventions catches the mistakes this team actually makes, which generic tooling does not. Bug detection focuses on patterns that have caused production incidents before.
Performance work is the highest-value target, since Roblox performance problems are often architectural and easier to catch as a pattern in code than as a symptom in a profiler.
Keeping humans in the loop
Mercury proposes and does not merge. Automated changes are reviewed like any other contribution, because a tool that quietly rewrites code produces a codebase nobody understands.
Asset validation is the clearest early win: naming, scale, pivot placement and topology conventions are objectively checkable and expensive to catch by eye.