=> TODO -next in middlewares
- why miiddleswares are used
- express.json( middleware)
- model methods
- find and findOne
- diff btwn patch and update
- schema checks and types
- validator
- deeper understanding of bcrypt
- deeper understanding of jwt npm and tokens....
- express.Router (deep understandign)
- password patch have to do own
- pre method in mongoose error handling from docs
- indexes in MDB.
- why creating lot of indexes in not recommended?
- $or query in mongoose (operator query logical)
- ref and populate
- $nin and $ne
- pagination