MongoDB Roadmap

MongoDB is the database commonly used in MERN apps.

It stores data as documents inside collections, which makes it flexible for JSON-like application data.

Study order

Documents -> CRUD -> Queries -> Schema design -> Embedding vs references -> Indexes -> Aggregation -> Mongoose -> Exercises

Do not treat MongoDB as "SQL but JSON". Document modeling has its own tradeoffs.

What matters most

• Design around how the app reads and writes data.
• Embed data when it is owned and usually read together.
• Reference data when it is independent or reused.
• Use indexes for frequent queries.
• Aggregation is for reporting and transformations.
• Mongoose adds schemas and validation at the application layer.

Interview angle

If asked about MongoDB, explain documents, collections, schema design, embedding vs referencing, indexes, aggregation, and how Mongoose helps in Node apps.