Recommendations to others considering Express.js:
If it solves your problem and your problem doesn't require too much security, just go with it! I do not recommend ExpressJS which requires heavy-lifting like machine learning. You are better off using Django or Flask with python instead.
ExpressJS can also be used with GraphQL. It also works flawlessly with MongoDB with mongoose.
With new frameworks like AdonisJS and Fastify, it could really be hard for ExpressJS to continue being what it is today. Review collected by and hosted on G2.com.
What problems is Express.js solving and how is that benefiting you?
I have made several APIs with it, the most prominent one being a Food Recipe search engine. Since there are a plethora of NodeJS libs available, they can be easily integrated with ExpressJS to solve almost any problem! I've also used it for very large projects and critical projects. Some of the APIs I am selling on an API marketplace are made with ExpressJS. I have used ExpressJS mostly with MongoDB with mongoose and the integration was smooth. Review collected by and hosted on G2.com.