How would you explain eventual consistency on a Swiggy-like order status?
PICTURE THIS: ASYNC / PROMISE
Simple meaning
The place-order API commits the order as CREATED and returns quickly
WHY — Microservices instead of guessing?
Why interviewers care about Microservices:
question about Microservices.
trade-offs, and what you would actually do on a Backend project - not buzzwords.
Name the idea, why it exists, then one short example.
End with when you use it and one common pitfall.
STEPS — What happens step by step?
Before you speak the answer, walk the interviewer through these steps:
- 1The place-order API commits
the order as CREATED and returns quickly
- 2restaurant accept and rider
assign arrive as later events.
- 3The UI polls or
subscribes until status catches up.
- 4You never promise a
fully assigned rider in the same synchronous transaction across three services.
- 5Common mistake
What juniors usually get wrong.
- 6Close
When you pick this over the alternative.
EXAMPLE — See it in action
Here's a short line you can speak, broken into clear beats:
Note: Adapt this scaffold to your own project — keep it under 60–90 seconds.
Key takeaway
The place-order API commits the order as CREATED and returns quickly restaurant accept and rider assign arrive as later events.