Do you have any issues with your current stack?

Hello Everyone,
My team and I are in the ideation phase for an open source project. We could use a word of advice or insight on currently popular/emerging technologies. What is a software technology/tool/service/framework that you currently use that you feel could be improved: anything from reducing render time, better UI features for the developer, caching, accessibility, or things that seem to be inconvenient. With such a variety of technologies and topics out there, it’s hard to know where to even begin researching, so we would greatly appreciate any help and advice, thank you!