Is MongoDB ACID Compliant? — Interview Answer — MongoDB Technical Interview Questions & Answers

Model answer covering single vs multi-document guarantees.

Is MongoDB ACID Compliant? — Interview Answer

  • Model answer: Single-document operations are ACID. Multi-document ACID needs an explicit transaction (replica set).
  • Do not claim Mongo has no ACID at all — that is outdated for modern versions.

Technical Interview Tip: Be precise: document vs multi-document.

Code Examples for Is MongoDB ACID Compliant? — Interview Answer

Is MongoDB ACID Compliant? — Interview Answer — working example

// mongosh / driver-style multi-document transaction (replica set / mongos required)
session = db.getMongo().startSession()
session.startTransaction()
try {
  const users = session.getDatabase("prep_pilot").users
  const accounts = session.getDatabase("prep_pilot").accounts
  users.updateOne({ email: "ada@example.com" }, { $inc: { points: -10 } })
  accounts.updateOne({ email: "ada@example.com" }, { $inc: { balance: 10 } })
  session.commitTransaction()
} catch (e) {
  session.abortTransaction()
  throw e
} finally {
  session.endSession()
}

Is MongoDB ACID Compliant? — Interview Answer — multi-document ACID transactions need a replica set (or sharded cluster) and a session.

How to Explain Is MongoDB ACID Compliant? — Interview Answer to an Interviewer

Is MongoDB ACID?

Yes for a single document Multi-document via transactions