Add design interview prep discussion

README.md

@@ -32,3 +32,35 @@ Topics for learning system design:
 This is an **early draft** of a **continually updated, open source** project.
 
 [Contributions](#contributin) are welcome!
+
+### Prep for the system design interview
+
+In addition to coding interviews, system design is a **required component** of the **technical interview process** at many tech companies.
+
+**Practice common system design interview questions** and **compare** your results with sample **discussions, code, and diagrams**.
+
+Additional topics for interview prep:
+
+* [Study guide](#study-guide)
+* [How to approach a system design interview question](#how-to-approach-a-system-design-interview-question)
+* [System design interview questions, **with solutions**](#system-design-interview-questions-with-solutions)
+* [Object-oriented design interview questions, **with solutions**](#object-oriented-design-interview-questions-with-solutions)
+* [Additional system design interview questions](#additional-system-design-interview-questions)
+
+#### For interviews, do I need to know everything here?
+
+**No, you don't need to know everything here to prepare for the interview**.
+
+What you are asked in an interview depends on variables such as:
+
+* How much experience you have
+* What your technical background is
+* What positions you are interviewing for
+* Which companies you are interviewing with
+* Luck
+
+More experienced candidates are generally expected to know more about system design.  Architects or team leads might be expected to know more than individual contributors.  Top tech companies are likely to have one or more design interview rounds.
+
+#### Any resources to prep for coding interviews?
+
+Check out the sister repo [**interactive-coding-challenges**](https://github.com/donnemartin/interactive-coding-challenges) for coding interview resources.