The bar you gotta clear to work on an internal application with 100,000 events/month
Interviewed a Senior Backend Engineer today.
Knew Redis, SQL, caching, all of it.
Then I asked:
A post goes viral.
100,000 likes per second.
Every like runs:
UPDATE posts SET likes = likes + 1
WHERE id = 42
The engineer said: add a cache.
Every write still lands on that one