How to Use This Course

Most people open a course like this and start reading at the top. That works if you have a month. It does not work if your onsite is on Thursday.

This lesson gives you three plans. Pick the one that matches the time you have.

Read a case study the hard way

Before the plans, one habit matters more than any of them.

When you open a case study, read only the problem statement. Then close the page. Spend ten minutes designing the system yourself, on paper, badly. Write down your requirements, a rough size estimate, and a first diagram.

Then read the lesson and compare.

The gap between your version and the lesson is the actual lesson. Reading first and agreeing as you go feels productive. It teaches very little. You will remember a design you attempted far better than one you read.

This takes longer per case study. Three case studies done this way beat all twelve read passively.

If your interview is in a week

Do not try to cover everything. Pick four case studies and do them properly.

A good set is Notification Service, Reddit, Payment System, and Flash Sale. The first two cover fan-out and read-heavy traffic. The last two cover money, correctness, and extreme contention. Together they cover most of what gets asked.

For each one: attempt it yourself first, read it, then take the chapter quiz.

Then read the requirements and estimation steps of three more case studies. Skip their detailed design. You are practicing the opening ten minutes of an interview, which is the part most candidates handle badly.

If you have a month

Work through all twelve case studies in order. They are arranged from medium to hard, so the difficulty increases steadily.

Two per week is a comfortable pace with a full-time job. Attempt each one first, as described above.

When a case study uses a pattern you do not know, stop and read that pattern. Do not read the whole patterns chapter up front. A pattern you read because a design needed it tends to stay with you. One read in advance usually does not.

In the final week, take the final assessment. Treat a wrong answer as a pointer to the lesson you should re-read, not as a score.

If you are studying without a deadline

Do the twelve case studies first anyway. They give you the context for everything else.

Then read the seven architecture studies. Dynamo, Cassandra, Kafka, Chubby, HDFS, GFS, and BigTable are the systems that most modern designs borrow from. Once you have seen how Dynamo handles conflicting writes, you will recognize the same idea in a dozen other places.

This is also the right time to read the patterns chapter end to end.

What the quizzes are for

Each case study chapter ends with a quiz. It asks a subset of a larger bank, so taking it twice does not give you the same questions.

Use it as a check, not as a grade. If you miss a question, the explanation names the idea you should go back to.

A note on the architecture studies

The seven architecture studies are long and dense. They are the most detailed material in the course, and they need slow reading.

If you open one before you are ready and it feels heavy, that is not a reason to keep going. Go back to the case studies and return to it later.

Key Takeaways

• Attempt a case study yourself before reading it. This is the single habit that matters most.
• With a week, do four case studies properly instead of twelve badly.
• With a month, do all twelve at two per week, in the order given.
• Read a pattern when a case study needs it, not in advance.
• The architecture studies come last, once the case studies feel comfortable.
• Quizzes are a check on understanding, not a score to chase.

The next lesson shows the structure that every case study follows, so you know what is coming before you open the first one.