Design a News Feed (Twitter Timeline)/Playground
A home timeline at 300,000 reads a second
Click a part to change it, put something in front of it, or kill it. Turn the traffic up. Every number moves as you go; nothing is graded. 300,000 timeline reads a second and 12,000 posts a second at peak; about 200 followers per post is assumed.
Running
- Requests failing
- 0%
- Backlog growing
- none
- Instances running
- 895
What goes through it
| Operation | Offered | Outcome | Wait | Up |
|---|---|---|---|---|
| Timeline reads | 300k/s | All served | 63 ms | 99.999% |
| Post lookups | 300k/s | All served | 40 ms | 99.999% |
| New posts | 12k/s | All served | 118 ms | 99.999% |
| Timeline insertsbackground | 2.4M/s | Keeping up | – | – |
| Follower lookupsbackground | 12k/s | Keeping up | – | – |
Wait is the expected time a caller waits; Up is the share of time every part it waits on is running.
What your changes did
Nothing yet. This is the reference design: change something to see what it buys and costs.
At this traffic
Everything is running within capacity.
Ask AI what your design does
AIThe numbers above come from a simple model. The AI reads your design, what you changed and these numbers, and explains where it holds and where it fails, citing how the engineers who built it did it. It can be wrong.