Inkwell is launching Groups, shared spaces where writers swap drafts. The product team's numbers:
- about 2.4 million people will use Groups each day,
- each makes about 50 requests a day, 9 reads for every write,
- the busiest hour carries about 3 times the average.
The founders want Groups fast at its busiest, and they don't want to pay for machines that sit idle.
What it does
- Read: a writer opens a group or a draft.
- Write: a writer posts a draft or a comment.
Workload
The busiest hour: a steady 4 000 rps, 90% reads / 10% writes, for 20 seconds, against 10 000 drafts.
How to build it
- Build client, load balancer, app server, database.
- Pick tiers and replica counts from your estimate: what can one app server and one database node take?
- Run it, then check the cost in the results header. Can you get the same speed for less?