Module 13 · Application protocols · Drill

Application protocols drill

Scenario prompts that check whether application protocols is usable under pressure. Answer out loud, then compare.

4 prompts25 minNew

0 of 4 graded

Prompt 1
You are migrating api.example.com from an old load balancer to a new one in another provider, with a hard requirement of no more than five minutes of mixed traffic. Today the A record has a TTL of 86,400 seconds. Write the cutover plan around DNS caching, including what can still go wrong.
Say your answer out loud first. Thirty seconds is enough.
Prompt 2
A mobile app on HTTP/2 shows long stalls on poor cellular connections, and the team proposes going back to HTTP/1.1 with six connections. Evaluate that proposal against moving to HTTP/3, explaining what each does when a packet is lost and when the phone switches networks.
Say your answer out loud first. Thirty seconds is enough.
Prompt 3
At 03:00 every client of your public API starts failing TLS handshakes. Ten minutes later, a second team reports that their new subdomain works in Chrome but fails from curl and the Android SDK. Diagnose both from TLS first principles and describe the controls that would have prevented them.
Say your answer out loud first. Thirty seconds is enough.
Prompt 4
Your product sends password resets, receipts and a weekly marketing digest. Users say resets often arrive late or in spam. Design the email sending system end to end, covering DNS records, sending path, separation of streams and failure handling.
Say your answer out loud first. Thirty seconds is enough.