Ask HN: Question from self-taugh developer, my app is slow. What do I do now?

I built a web app. To be precise, it is a web app inside Wechat ( I am in China).

Every day there is around 200 users, and it generates me some ramen profit.

Users report that my web app is sometimes slow.

I know that there are many plausible causes. But before I jump into the rabbit hole, I want to ask for your kind advice.

What is your mental framework to deal with such a problem?

FYI, my app:

- is built with NodeJS

- ran on a cloud server with 2 core CPU, 2G Ram, and 1M bandwidth

- is a CRUD app

I have learned about building apps from the web, mostly from Udemy and Youtube. Someone has told me to not worry about performance. `Make it work, then make it better`.

Now that I have learned how to make it work, how can I learn how to make it better? Do you have any links or materials to share?

Thanks a lot.