ByteByteGo on YouTube · Open on YouTube
System design and architecture · Proficient · Lesson 61 of 98 · 9 min video, then about 3 hours of practice
Back-of-the-envelope estimation
After this you can estimate requests per second, storage and bandwidth for a system from a few stated assumptions, to within an order of magnitude.
Why it matters
Before designing anything, size it. How many users, how many requests per second at peak, how much data per year. These numbers decide whether you need one database or twenty, and whether a design discussion is about real problems or imaginary ones. Learn the handful of latency numbers and powers of ten worth memorising, and practise stating assumptions explicitly. Trap: false precision. You want the order of magnitude, quickly.
How to use this resource
The method and the numbers worth knowing, in under ten minutes.