Why should you care?

Sessions, OTPs, password-reset tokens, and temporary uploads should disappear without a custom cron at first.

See it live — copy this example

Open mongosh or MongoDB Compass, select database nosqlverse, then run the example. Change one field and run again.

db.sessions.insertOne({
  userId: ObjectId(),
  token: "abc",
  createdAt: new Date()
})
db.sessions.createIndex({ createdAt: 1 }, { expireAfterSeconds: 3600 })
db.sessions.find()

Run Example »

Edit the code below and click Run to see the result in Toolliyo’s live editor.

What happened?

• createdAt is a real Date.
• The TTL index expires documents 3600 seconds after createdAt.
• The delete is not instant to the second — a background job runs periodically.

Practice next

1. Create sessions with createdAt: new Date().
2. Create TTL index with a short expireAfterSeconds (e.g. 60) for a test.
3. Wait and confirm documents disappear.
4. Use expireAfterSeconds: 0 with a absolute expireAt date field pattern.
5. Partial filter TTL only for type: "otp".

Remember

TTL indexes auto-delete old documents. Need a BSON date field. Perfect for sessions and OTPs.

OTP collection cleanup

Login OTPs expire in 5 minutes via TTL on createdAt.

Outcome: No leftover codes clutter the database.