I'll go first.
I love to ask, design: Google docs, Google maps, Spotify Play store/App store True caller Zerodha/Share market terminal
What are some of your favourite questions?
Design a scalable feature flagging system.
It's not that complicated I guess.
All you need is a distributed kv store in backend maybe Dynamo or aerospike and a thin api layer that supports SSE and couple of rest endpoints for polling and pulling.
Since the client SDK will be potentially installed on billions all you need to take is lots of concurrent connections.
Put a haproxy cluster in the front, write the backend in go or rust, use AWS autoscaler.
This covers your Boolean and multivariate flags.
What's missing ?
Doesn't cover all my requirements. You didn't ask for them at all
Bookmyshow
Oh tell me
i really like designing the booking apps, be it a movie or hotel especially the DB designing part, the part where we get many to many cardinality it gets fun.
Why no one designs IRCTC / ADHAAR or Cowin.🤔. Because most of the engineers on the hiring team are afraid to ask the question as they aren't sure either. The fear flows top down in the org- of being wrong and being gossiped around.
When did we become like this 😔
Design an experimentation platform
I've asked this once to a principal architect.
Design a highly concurrent version control system.