Section checkpoint

Caching and Delivery

6 questions drawn from the 2 chapters in this section. If most land on the first try, you are ready for the next section. If not, the explanation after each answer says which idea to revisit.

Checkpoint

6 questions · first-try answers earn the most XP

1. Your team wants to delete a cache key the instant a product price changes. What is the most reliable approach?

2. Which layer should sit in front of your database for a read-heavy page?

3. A cache hit rate of 95% still leaves your database handling 5% of a large request volume. Is that a problem?

4. Which of these payloads belongs on a CDN according to the chapter's rule?

5. Why does putting a CDN in front of assets help a user in Mumbai when the origin is in Virginia?

6. What does the `immutable` cache directive actually tell a browser?

What this checkpoint covers

Caching Basics
Cache-aside, TTL, CDN, stampede in one story.
CDN & Edge Caching
Hot assets at the edge, TTLs that save your DB.

Put it to work in a drill

The product cache outgrows its memory
Beginner
A price cache with no eviction
Beginner
Customers see yesterday's price
Beginner
The database spikes every minute
Intermediate
An old name comes back for a day
Senior

Next section: Messaging and Realtime