End user performance concerns - another contribution to a LinkedIn collaborative article:
I just finished writing a contribution to this article:
It's a common problem, but it can also be a real bugger to track down the real source of the issue. I covered some of them in the limited space I was provided in my contribution, plus a bit more I took advantage of by replying to it. But honestly, this a really deep subject which the article didn't allow nearly enough space to make the kind of contribution I'd have liked to. I can tell you from having been involved in tracking down the source of more than one of these, it's not a trivial task! Check your logs, looking for user patterns, filing a case with Salesforce so they will look at org data you don't have access to, and a whole lot of other things, are very important things to do before you spin your wheels by altering code or changing your org configuration!
These things typically will have a pattern that may not be obvious at the outset. I cover some of them in my contribution. With pages being compiled locally when using using Lightning pages, the machine being used can have a LOT to do with these kinds of problems. There's also a huge difference for users that leverage the console vs those that use a standard layout and open multiple tabs! The console is far more efficient at managing hooks back to Salesforce and will use far less memory to have the same number of records open. Try it and compare memory usage if you're skeptical.