Tuesday, August 02, 2022

Stack Overflow: simple, fast, monolith, no-cloud

interesting podcast about engineering of Stack Overflow app/site

Hanselminutes Technology Podcast - Fresh Air and Fresh Perspectives for Developers - Engineering Stack Overflow with Roberta Arcoverde


It is still a “monolith” .net app, running on total of only 9 servers (!!!)
All 200 related web sites are on same servers, with same code, "multi-tenant"
Deployment time: 4 minutes

No cloud, they manage they own servers, as they have started.
And the utilization of those servers is less than 5% (!!).
So, in theory, it could run on a single web server.

And they are NOT using caching anymore. No Redis.
Apparently the “hit rate” was not sufficient to justify complexity.
Average response time, without caching: 20 ms (!!!).
9000 requests per second, billions of requests per month.

The database is quite large, with 1.5 TB RAM (!!!).
As far as I know, no “cloud” provider have such large servers yet.

And no “microservices” either…
Some Kubernetes for side projects, maybe.

The (open source) ORM (Dapper) used is custom-build, using mostly “raw sql” for efficiency.
https://github.com/DapperLib/Dapper

Simplicity is underrated!

Total of 50 developers
serving 50 million monthly users (!!) (edited)