The backend has to handle all of the scale. That's where the real difficult engineering comes in and if you're using JS there, you're going to pay a huge price.

The backend has to handle all of the scale. That's where the real difficult engineering comes in and if you're using JS there, you're going to pay a huge price. It doesn't seem like many front-end JS developers understand that pulling data from different places isn't actually a hard problem but instead correctly storing and managing that data at scale is where the actual engineering happens.