Layer 3 · Go deeper · 8 min
Go deeper
Size it, build it, then make the calls an interviewer will push you on.
Back of the envelope
Size it up
Tap through each step of the arithmetic.
How many Temporal Cloud actions a second does that sale bill?
How many loop iterations before a workflow’s history is terminated?
Build-up · 6 steps
Crash a worker, replay the order
One order, two workers. Watch the history fill up, Worker A die, and Worker B rebuild the run by replay without repeating a finished step.
Step 1 of 6
Start order-42
The order service starts workflow order-42. Worker A long-polls, runs the code until it blocks and returns commands; Temporal appends each as an event in the history.
4 interview moments
You’re the candidate
The interviewer pushes on the hard parts. Pick an approach and see how it holds up.
Deep dive 1 of 4
Interviewer
“A worker dies right after the gateway charged the card, before it reports back. How do you prevent a double charge?”
Your move. Pick an approach:
Deep dive 2 of 4
Interviewer
“You must add a fraud check before charging. Two million orders are in flight, some asleep on timers. How do you ship it?”
Your move. Pick an approach:
Deep dive 3 of 4
Interviewer
“Book a Goa trip: flight, hotel, then charge the card. The card is declined. How does your workflow clean up?”
Your move. Pick an approach:
Deep dive 4 of 4
Interviewer
“Each food order is a Temporal workflow. Riders’ phones also stream GPS pings throughout delivery. Where do the pings go?”
Your move. Pick an approach: