Should You Buy Interview Cake?
Having completed almost every Interview Cake question, I can definitely say it is worth purchasing.
For many of our clients that haven't interviewed in a few years or taken a data structures or algorithms course many years ago, Interview Cake has proved very helpful. It provides a great refresher on data structures and is a well organzied, efficient way to prep.
Interview Cake is designed for users to pick and choose which topics they want to review, allowing you get a tailored refresher course. When I used Interview Cake, two years had passed since I had taken a formal data structures course, so of course I had forgotten many of the details. By selectively focusing dynamic programming and greedy algorithms - the areas I found most challenging - while skipping fundamentals like Big-O Notation, I was able to condense my interview preparation into a few weeks.
Unfortunately, Interview Cake's readings aren't thorough enough to build a foundation from scratch if you have never learned about Data Structures and Algorithms before. Time permitting, it would make sense to start with a more in-depth course.
Ultimately, the two best features of Interview Cake are the hints and the solutions - those two features alone make it worth purchasing.
Interview Cake Pricing
Interview Cake has two pricing models:
- $149 for 3 weeks
- $249 for 1 year
Interview Cake's refund policy is the best in the industry. Parker - the Interview Cake founder - provides a "no questions asked" refund within in the first 100 days. After testing the refund, Parker indeed honored it.
You can get interview cake for free (if you are a student). To sign up for interview cake for free you just need the Github Student Developer Pack.
Interview Cake Deep Dive
Interview Cake Data Structures and Algorithms Readings
The course readings cover everything from the very basics (Big-O Notation) to more advanced concepts like Dynamic Programming. All of the core material for software engineering interviews are included. In addition, Interview Cake has readings on less frequently seen topics including Bit Manipulation.
Unfortunately, Interview Cake doesn't have readings on advanced algorithms like Dikstra's or Bellman-Ford. Thankfully, both are rarely required in interviews. However, if an interview question does require them, it is generally very challenging to solve the problem without prior knowledge of the algorithms.

Interview Cake Questions
There is just enough questions to build a foundation. With ~50 questions you will be able to learn and practice the fundamentals but there isn't enough content to make you an interviewing master.
If you only have a few weeks for interview preparation then Interview Cake is good fit since the questions are hand selected and cover all of the fundamentals.
All the questions in Interview Cake's main course are valuable. However, there are questions on extended topics such as PHP and QA. For Software Engineering interviews at Google, Facebook, Microsoft, Netflix etc., neither will be needed.
To maximize your learnings on Interview Cake, try starting with questions in a given topic (e.g. graphs) and then progress to the randomized questions.
Interview Cake claims to have questions sorted by company. However, with such a small question bank, they are poorly indexed and not fully relevant.
If Interview. Cake extended their question bank to 100+ there would be enough to do all of your practice solely on Interview Cake but today, there isn't.
Interview Cake Hints
When you are doing a real interview at Facebook or Google every interviewer knows that they are allowed to give you hints. When you get stuck, asking for some guidance can be the difference between failing or passing the interview. On most prep sites if you can't get the answer they just show you the whole solution. Interview Cake will give you hints so that you can continue working on problems instead of just giving up and looking at the solution. Their hints are very good. They start with small nudges and then work up to giving you the brute force solution and prompt you towards the optimal answer.


Interview Cake Solution
Good solutions are ones that are right. Great solutions are well written and easy to understand, allowing you to quickly improve and learn.
Interview Cake solutions are well thought out, visualized and explained. The only thing missing is there are no videos for visual learners.

Often when you read a solution it can be hard to apply the learnings to the next problem you do. Interview Cake helps you do that by sharing a summary of the learnings. I found this to be helpful as I prepped.

Should You Buy Interview Cake?
I did and would recommend it. Interview Cake is a very efficient way to build a good foundation in a short period of time. Purchasing the 3-week course, complete the readings and practice questions and then focusing on LeetCode Medium and Hard problems to get more practice would set you up to ace your interviews.