[trevi]

Look at hotels.com, which in many ways is comparable. It has around 1000 employees (one thousand). From wikipedia:

Hotels.com has 85 websites in 34 languages, and lists over 325,000 hotels in approximately 19,000 locations.

Going back to your comments, you could rephrase some of the earlier comments as: why on earth would you need millisecond performance improvements for a website/product listing rentals?

[dmode]

Hotels.com is part of Expedia group. Expedia has 25k employees.

Millisecond improvement is needed because travel is commodity and bounce rate is very high. If website doesn't load in time, visitors bounce off to other providers