Scaling a social network on a whiteboard

One of the worst interview questions is “how would you design and scale Instagram from scratch on a whiteboard?” This is a very complicated question and typically used to gauge your knowledge of how things scale. This is also something that is limited to folk knowledge, so in this talk I will show you how you get from “humble beginnings” to “globe spanning monstrosity”.

The goal of this talk is to make knowledge of how things scale in the real world accessible to everyone. Knowing how things happen means you can build systems that can scale for tomorrow without being caught in the “what if"s or the “how about"s that this interview question forces you into. This is aimed at people of all skill levels to help them skill up and pass these kinds of interviews with knowledge they’d certainly learn on the job anyways. The talk will be light-hearted with jokes aplenty.

This talk will start from the humble beginnings of a single app on a single server with sqlite and slowly build up through layers of abstraction until it becomes a giant globe-spanning monster like Twitter is today. Each stage will be explained and the tradeoffs that are usually made will be shown off.

Hopefully this will make that interview question that I really hate not viable for the mainstream tech interview circle. I hate this question because it takes an hour and usually feels like you’re being trolled every time the interviewer throws a new reality circumstance at you for you to handle.

This question is a shibboleth that is used to filter out people that have already seen horrors beyond mortal comprehension and it actively excludes people who could have otherwise done the job and learned the infrastructure history as needed. I’d love to see it no longer be viable.



Xe Iaso

I’m Xe Iaso, I’m a technical educator, conference speaker, twitch streamer, vtuber, and philosopher that focuses on ways to help make technology easier to understand and do cursed things ...