What are databases in mongoDB?

0-2 years experience

1. 1You need to add a new feature that stores user profiles separately from logs. How would you decide whether to put them in the same MongoDB database or create a second database?
2. 2If a developer runs `db.dropDatabase()` by mistake in a development environment, what immediate steps would you take to recover the data?

2-5 years experience

1. 1During a rollout, you notice that reads from the 'analytics' database are slower than expected while the 'app' database is fine. What could cause this discrepancy and how would you troubleshoot it?
2. 2Your team wants to enforce different read/write permissions for two databases on the same cluster. How would you configure roles and what trade‑offs should you consider?

5-8 years experience

1. 1You are designing a multi‑tenant SaaS platform on MongoDB. Explain how you would use databases versus collections to isolate tenant data, and discuss the performance and operational implications of each approach.
2. 2A sudden spike in traffic causes one database to hit its storage quota while others remain underutilized. How would you redesign the deployment to handle uneven growth without downtime?

8+ years experience

1. 1Your organization plans to migrate from a monolithic MongoDB deployment with many databases to a sharded cluster. Outline the migration strategy, focusing on database‑level considerations, data consistency, and impact on existing applications.
2. 2When evaluating long‑term governance, how would you decide on a naming convention and lifecycle policy for databases across multiple product lines to balance security, cost, and operational simplicity?