While a PDF will give you the theory of distributed systems, remember that the real learning happens when you practice on a whiteboard with a timer. Download the primer, print the section on load balancing, memorize the CAP theorem, and practice the URL shortener until you can do it in your sleep.
If you cannot estimate that a Twitter user generates roughly 1.2KB of data per day, the PDF won't save you. Practice the numbers. the system design primer pdf
The PDF teaches you what to build, but you need to learn how to communicate it. While a PDF will give you the theory
“I stopped guessing,” he said. “And I started designing.” Practice the numbers
He flipped to “Caching.” The PDF showed a chef’s kitchen. The database was the deep freezer in the basement—cold, reliable, but slow. The cache was the stainless-steel countertop right next to the stove, holding the most popular ingredients at the chef’s fingertips. Alex realized his app was sending the chef to the basement for every single salt request.
