Stress when interviewing is similar, but not the same as on the job stress.
One major factor, with a job: you're still getting paid. I think the economic anxiety one faces is pretty stark, if you fail a job interview you're going to be unemployed until you can pass the next one.
Yes, interview stress is completely different. You have to commit a pretty egregious offense on the job to get fired on the spot, but literally anything you do during a job interview can cause you to lose the job.
Also, performing in front of strangers is completely different from performing in front of people you already know (co-workers).
It's extremely common for people to be nervous when meeting strangers but fine among associates. This is such a blatantly obvious empirical fact, it mystifies me how the tech industry can act as if this phenomenon does not or should not exist.
And often you won't have any idea what caused you to lose the job in a particular interview. There's generally no feedback at all so it can be very difficult to try to improve.
One major factor, with a job: you're still getting paid. I think the economic anxiety one faces is pretty stark, if you fail a job interview you're going to be unemployed until you can pass the next one.