> Do say: "I optimized a high-throughput distributed system to prioritize user retention metrics, reducing latency by 150ms through a custom caching layer."

Ugh. Pain. I'm hiring, and I've been filtering out resumes that are heavy on these kinds of metrics.

Because I literally get thousands of entries with these kinds of wording. Often with excessively precise numbers, like "by 23.5%".

My problem is that it's hard to tell the amount of real work it took to do that. It might have been as stupid as creating an additional index in the database, or it might have involved a deep refactoring across multiple systems with a zero-downtime gradual rollout.

I would prefer something like: "I worked as the hands-on leading developer to do a large-scale refactor on the highly loaded front-end network routing system, resulting in user-visible latency decrease on the Youtube front page".

For me the key words are: "hands-on" (and not just writing a product brief and getting resources for it), "large-scale refactor" (so likely not just creating an additional database index), "highly loaded".

FWIW, I agree that less ink on a resume is usually a higher signal, and I also find that indicators for “ownership”, social trust, autonomy, and proxies thereof are more valuable than number go up narratives.

But sometimes people feel like they must play this game to get past the pre-interview loop screen; I’ve interviewed plenty of people with number go up narratives who’ve done exceptionally well. It’s challenging to make hard and fast rules!

There's no such thing as a "hands-on leading developer" on a "large-scale refactor" at Google, it'd be like saying you were the hands-on leading mechanic on building the 787 dreamliner.