T.T.F.U
There is a metric used for website performance known as Time To First Byte or TTFB:-
Time to first byte (TTFB) is a metric for determining the responsiveness of a web server. It measures the amount of time between creating a connection to the server and downloading the contents of a web page. Stackpath
When it comes to starting a new job the metric that I like to focus on is Time To First Usefulness or TTFU
It's the amount of time between starting a new job and the first time you do something actually useful for your employer. Sadly it will not be measured in milliseconds like TTFB.
The first couple of weeks in a new job is always strange and exciting and maybe a little bit scary. A feeling of "OMG, WTF have I done?" is not uncommon and the thing that I always find calms me down is when I start actually doing something useful in my role.
Let's hope the TTFU is short.