As an espresso drinker with a good machine and grinder, and lots of variety with mostly Italian beans, it depends, as the OP already indicated. I only buy low or at most middle caffein content beans to begin with, but you can get high caffeine beans for espresso easily. Easiest method: Increase the amount of Robusta.

Good vendors should have things like caffein content in their product description. I mostly buy from an online vendor that lists the exact roast date and also shows caffein content for each product (https://www.espresso-international.com/ - their only disadvantage is the use of some pretty light GRAY for most text, another topic, too many websites do this for reasons I cannot understand).

Many years ago, when I still lived in the Bay Area, the Cappuccino I got at a certain Berkeley coffee shop always made my heart go BOOM BOOM BOOM. Whatever concoction they brewed certainly had very high caffein (and I hated it, but the place was great). The ones I make myself now I can drink at 10 pm and be completely fine (I only drink 2-4 max espresso per day, and can easily drink zero if I'm away and have no access to good espresso, so I'm not addicted and just "used to it").

Sometimes I compromise and buy medium caffein beans when it's something good, but those I can feel just a little.

All of that just means you have to exert some control over which beans you consume, if you want to keep caffein low. On the plus side, if you stick to 80%-100% Arabica (the rest Robusta) it's not hard at all. If you like mixes with high Robusta ratio it gets much harder. Caffein free roasts exist though (examples: https://www.espresso-international.com/decaffeinated-coffee), but that choice severely limits your options.