Yeah, I’m sure my Claude generated email client could be even faster if I wrote it by hand. Modern computers can retire billions of instructions per second per core. All operations that aren’t downloading or processing gigabytes of data should be instant on modern computers.

Claude’s toy email client gets closer to the speed limit than Gmail does. Why is Gmail so slow? I have no idea.

you have to ask it to profile and optimize the code for you. Then have it document the changes and run it in a loop. It’ll do wonders.

I asked a cursor agent to do the same for a geotiff to pmtiles converter. It managed to optimize the performance from tens of days to half a day for the case I wanted to solve.

Look, it's an RSS reader, not a numeric solver for PDEs. What I clearly meant was: Every interaction is instant, no noticable delay at all, except the reader view, which makes a network request to an external site.

Given parent and GP are both using Claude... have you tried Claude? (I say this as someone who has not tried Claude recently. I did try Claude Code when it first came out, though.)