A very short overview of what it takes to design High scale systems. I remember one of my first interviews at a tech company where the interviewer asked me a question to the tune of “Today I have a 100 users if I had 100,000 users tomorrow how would my system architecture be different?”. The answer to that question is what you would learn in the following sections. 

This covers most of the concepts of building a system at scale like Scalability, Reliability, Availability, Efficiency, and Manageability. And goes into good depth on each of the topics. In addition to this I would really recommend reading “Art of Scalability” this would give you a clear picture of why System design and building systems that scale are so critical. This foundation would help you as you progress through the course as it will help in understanding the complexities of WHY each piece is important. 

I would also recommend doing the below Youtube videos that are free:-

Four Distributed Systems Architectural Patterns by Tim Berglund

System Design Basics: Horizontal vs. Vertical Scaling

Lecture 9 Scalability Harvard Web Development David Malan

Load balancing is one of the most critical pieces of building a system at scale. This section has some neat diagrams explaining how load balancers work and benefits and the various types of load balancing are made crystal clear to the user. Interestingly the author also provides some good links to further reading. 

Really well written and likely a less familiar topic for many. This is a very common interview question so I am glad that this topic is covered. Here we primarily learn about why one would need to do data partitioning and the how-to partition your data and then move on to the considerations while partitioning your data. 

This is another topic interviewers look for form candidates. This also is one of those topics that is used to gauge the seniority of the candidates. The information provided here though accurate could have been more elaborate in my opinion. But you should be able to find some good articles on the internet on this topic. I really do not fault the author here as I believe you could probably write a book on this topic alone.

For that coming from an orgs that are primarily using RDMBS this is a good primer. The authors have done a good job giving you a neat overview. They go over the difference between the two and then dive into which type of DB to use and why.
However, since this is one of those hot topics everyone talks about I would really recommend reading No SQL distilled by Martin Fowler. It’s a pretty easy read, you could finish this in a couple of hours.

One more of the complex topics covered nicely using a diagram that the user can click through. It goes over the reason why hashing is so important in a distributed caching system.

This gives the reader an overview of Ajax Polling, HTTP Long-Polling, WebSockets, Server-Sent Events (SSEs), This chapter could have been more detailed into the reasons why these are important.

1. Functional requirements
2. Non-Functional requirements
3. Extended requirements.

There are three sub-topics covered under this:-

1. Traffic Estimates 
2. Storage Estimates
3. Bandwidth Estimates

Depending on the size of your storage how do you partition your data when using a traditional DB. This in some solutions is more detailed and others. The author in some cases talks more about the principles rather than how it would actually impact this solution we are designing. 

How to use a cache, is the system write-heavy or read-heavy and correspondingly who would you design your application. Some good examples of using CDN here as well.

Neat stuff like is this open to all users, does the user need to be authenticated? Is the URL private of public etc. This is a good interview discussion point and it’s nice that the author has covered this topic.