I'm a quantitative finance / actuarial programmer. I've flipflopped between the programming and business side a few times in my life. At one stage I was in the Actuarial Valuations team, responsible for the periodic valuation of a set of life insurance books. Timelines were very tight, input data was a mess, the products themselves were complex. This wasn't easy stuff. During valuation time all of us were on edge.

But for some reason, being interrupted then didn't cause nearly as much damage to my mental house of cards as they do now, where my day job involves translating messy actuarial spreadsheets to code.

I can't put my finger on it. Both tasks were complex. Maybe the fact that actuarial valuations (like most financial roles) are based on spreadsheets and you have a visual model right in front of you, or accessible within a few clicks. I think that relieves some pressure on the mental model.

Programming, on the other side, even with all the IDE tools like a watch list and call stack, seems to require a larger mental stack, given the same complexity in another field.

Side note: work from home has been a dream come true in terms of the disappeance of interruptions. But I do miss the coffee breaks with colleagues (or what others would call water cooler conversations).