MongoDB Data Modeling Patterns

MongoDB schema design often uses repeatable patterns.

Patterns help solve common document modeling problems.

Embedded document pattern

Use when child data is owned by parent and read together.

Example:

{
  "user": "Asha",
  "address": {
    "city": "Pune"
  }
}

Reference pattern

Use when related data is independent or reused.

{
  "postTitle": "MongoDB",
  "authorId": "user_123"
}

Subset pattern

Store frequently needed child data inside parent, and full data separately.

Example: product page stores latest 3 reviews embedded, all reviews in another collection.

Computed pattern

Store precomputed values when calculating them every time is expensive.

Example:

{
  "productId": "p1",
  "reviewCount": 128,
  "averageRating": 4.6
}

Interview answer

MongoDB data modeling patterns include embedding, referencing, subset pattern, and computed fields. These patterns are chosen based on read/write access patterns, data growth, and consistency needs. Good MongoDB design avoids blindly normalizing everything or embedding everything.