Coding Interview University

Forked from John Washam. 1
This is my journey towards feeling less like an impostor.

Some resources are continuously updated, for others I will “finish” and mark my progress.

Progress Tracking

Don’t feel you aren’t smart enough

Interview Process

Languages I will study

  • Python
  • JavaScript

Before you Get Started

You Won’t Remember it All

Use Flashcards

I made a couple of changes to the original project to be able to write Markdown in flashcards. For the original repository checkout in the repo above.

Note on flashcards: The first time you recognize you know the answer, don’t mark it as known. You have to see the same card and answer it several times correctly before you really know it. Repetition will put that knowledge deeper in your brain.

Cheatsheets and review, review, review

Study cheatsheets when you have spare time. Take a break from programming problems for a half hour and go through your flashcards.

Prerequisite Knowledge

The Daily Plan

Some subjects take one day, and some will take multiple days. Some are just learning with nothing to implement.

Each day;

  • Solve at least 3 Daily Coding Problem questions.
  • Solving about 10 - 15 Leetcode2 per day would put me about 700 questions total.
  • Take one subject from the list below, watch videos about that subject, and write an implementation in:
    • Python - with and without using built-in types
    • Javascript - with and without using built-in types
    • and write tests to ensure I’m doing it right, sometimes just using simple assert() statements
  • Exercism for Python and Javascript

John Washam’s practice repo: Python

Why code in all of these?

  • Practice, practice, practice, until I’m sick of it, and can do it with no problem (some have many edge cases and bookkeeping details to remember)
  • Make use of built-in types so I have experience using the built-in tools for real-world use (not going to write my own linked list implementation in production)

I may not have time to do all of these for every subject, but I’ll try.

Write code on a whiteboard or paper, not a computer. Test with some sample inputs. Then test it out on a computer.

Algorithmic Complexity

Book List

Interview Prep

Language Specific



  • YDKJS [2019-06-26]
    • YDKJS: Up & Going [2019-04-20]
    • YDKJS: Scope & Closures [2019-04-25]
    • YDKJS: this & Object Prototypes [2019-05-10]
    • YDKJS: Types & Grammar [2019-05-15]
    • YDKJS: Async & Performance [2019-05-20]
    • YDKJS: ES6 & Beyond [2019-06-26]
  • Effective Javascript [2019-07-08]
  • JS for impatient programmars

Tool Specific

GNU Make

Software Engineering

  • The Mythical Man-Month
  • Design Patterns
  • Algorithm Design Manual (Skiena)
    • As a review and problem recognition
    • The algorithm catalog portion is well beyond the scope of difficulty you’ll get in an interview.
    • This book has 2 parts:
      • class textbook on data structures and algorithms
        • pros:
          • is a good review as any algorithms textbook would be
          • nice stories from his experiences solving problems in industry and academia
          • code examples in C
        • cons:
          • can be as dense or impenetrable as CLRS, and in some cases, CLRS may be a better alternative for some subjects
          • chapters 7, 8, 9 can be painful to try to follow, as some items are not explained well or require more brain than I have
          • don’t get me wrong: I like Skiena, his teaching style, and mannerisms, but I may not be Stony Brook material.
      • algorithm catalog:
        • this is the real reason you buy this book.
        • about to get to this part. Will update here once I’ve made my way through it.
    • Can rent it on kindle
    • Answers:
    • Errata

Data Structures

More Knowledge


As a summary, here is a visual representation of 15 sorting algorithms.
If you need more detail on this subject, see “Sorting” section in Additional Detail on Some Subjects


Graphs can be used to represent many problems in computer science, so this section is long, like trees and sorting were.

Even More Knowledge

Final Review

This section will have shorter videos that you can watch pretty quickly to review most of the important concepts.
It’s nice if you want a refresher often.

Coding Challenges

Coding challenge practice is not about memorizing answers to programming problems.

Why you need to practice doing programming problems:

  • Problem recognition, and where the right data structures and algorithms fit in
  • Gathering requirements for the problem
  • Talking your way through the problem like you will in the interview
  • Coding on a whiteboard or paper, not a computer
  • Coming up with time and space complexity for your solutions
  • Testing your solutions

Before Starting:

Interview Handbook:

This resource contains related coding challenges for each topic mentioned here.

Coding Challenge Videos Resource Dump:

Coding Sites:

Mock Interviews:

System Design

Main resources


Your Resume

Get reviewed by:

Networking and Job Applications

Close to Interview

Be thinking of for when the interview comes

Think of about 20 interview questions you’ll get, along with the lines of the items below. Have 2-3 answers for each.
Have a story, not just data, about something you accomplished.

  • Behavioral Questions
  • Why do you want this job?
  • What’s a tough problem you’ve solved?
  • Biggest challenges faced?
  • Best/worst designs seen?
  • Ideas for improving an existing product.
  • How do you work best, as an individual and as part of a team?
  • Which of your skills or experiences would be assets in the role and why?
  • What did you most enjoy at [job x / project y]?
  • What was the biggest challenge you faced at [job x / project y]?
  • What was the hardest bug you faced at [job x / project y]?
  • What did you learn at [job x / project y]?
  • What would you have done better at [job x / project y]?

Have questions for the interviewer

Some of mine (I already may know answer to but want their opinion or team perspective):

  • How large is your team?
  • What does your dev cycle look like? Do you do waterfall/sprints/agile?
  • Are rushes to deadlines common? Or is there flexibility?
  • How are decisions made in your team?
  • How many meetings do you have per week?
  • Do you feel your work environment helps you concentrate?
  • What are you working on?
  • What do you like about it?
  • What is the work life like?

Additional Learning

Keep track of your progress on Programmer Competency Matrix.

These topics will likely not come up in an interview, but I added them to help you become a well-rounded
software engineer, and to be aware of certain technologies and algorithms, so you’ll have a bigger toolbox.

Additional Detail on Some Subjects

I added these to reinforce some ideas already presented above, but didn’t want to include them above because it’s just too much. It’s easy to overdo it on a subject. You want to get hired in this century, right?

Video Series

Sit back and enjoy. “Netflix and skill” :P


Best resource is The Morning Paper, a short summary every weekday of an important, influential, topical or otherwise interesting paper in the field of computer science. Some of the papers may be hard to follow. But the writer is an expert in none of them as well.4


  1. See Coding Interview University on GitHub ↩︎

  2. Leetcode ↩︎ ↩︎

  3. CS Career Hackers Discord Channel ↩︎ ↩︎

  4. The Morning Paper About Page ↩︎