Hack Reactor Interview Process and Prep Tips

Update (12/6/2016) - After 2 years of working in software engineering, I decided to start a podcast called Breaking Into Startups where we interview top bootcamp founder and alumni who broke into software engineering. Check it out http://breakingintostartups.com!

My Hack Reactor Interview Process

After weeks of researching coding bootcamps, I was convinced that I wanted to attend Hack Reactor except for a “minor” problem – the admission challenge. From everything I gathered to that point, the technical interview would consist of a 45-minute session over Skype where I would be asked to solve a series of coding challenges using my knowledge of JavaScript. For those less familiar with programming, an example of a coding problem would be something like building a function that checks to see if a number is prime. For starters, you have to know enough basic math to know what constitutes a prime number. Secondly, you have to quickly come up with the rules to determine if the number is prime. Lastly, you have to apply your knowledge of JavaScript to build these conditions into a function. If this doesn’t sound scary to you yet, remember that you have to do it in a relatively short period of time while somebody is watching your every move! I was terrified, to say the least.

That night I ended up reading as many Hack Reactor student blogs as I could find in search for any insight about the interview process. After reading about a dozen of them, I noticed a reoccurring theme – every applicant thought they absolutely BOMBED it when they took it! This wasn’t particularly reassuring considering a lot of the applicants were coming from some sort of coding background. All of a sudden, getting into Hack Reactor started to seem like a distant reality. The only sort of good news for me was that a lot of the same people who thought they BOMBED it, ended up getting in. Could it be that the interviewers intentionally pushed the boundaries in order to see how much the candidates actually knew? If that was the case, I had to REALLY start studying in hope that the little knowledge I can accumulate before I apply can shine through in my interview.

What you’ll find below are the steps that I took to prep for the technical interview with Hack Reactor. A lot of the study tips I borrowed from other students' blogs (Forrest, Amira Anuar, Austen Talbot). In order to maintain ethicacy, this blog is NOT intended to provide you with the answers to the problems that Hack Reactor asks during its interview. Instead, I’m sharing what I did to prep in order to help you should you decide to apply to Hack Reactor too.

Hack Reactor’s Website

The interview tips on Hack Reactor’s website were a great starting point. The courses on Codecademy and Eloquent JavaScript provided a great introduction to the JavaScript synthax. However, after finishing everything Hack Reactor recommended, I still had a feeling that I was missing the broader picture. I had a general understanding of the main concepts but if you had asked me to explain the difference between a “variable assignment” and a “variable declaration”, I would not have been able to answer. According to Hack Reactor, it should take a “great” applicant between 10-15 hours to prep for the admission challenge. This may be right, but since I was starting from a relatively low base, I knew I needed to get more practice.

Additional Prep

The JavaScript Road Trip Parts 1-3 on CodeSchool do an amazing job reinforcing the crucial JavaScript concepts with many examples and little practice problems. This gave me a more in-depth look into how to work with functions, objects, closures, hoisting and callbacks. Once I completed these three courses, I went on to take the Try jQuery and jQuery: The Return Flight course which were fun little courses that gave me a glimpse into what you can actually build with JavaScript. I then went to JavaScript-is-Sexy and read every article on there. Make sure you really understand the concepts of variable scope, closures, hoisting, and callbacks.

I then returned to Eloquent JavaScript and re-read Chapters 1-6. I would say, the exercises in Chapters 5-6 are a good assessment whether you are ready to take the admission challenge.

Game Time

Once I felt confident in my ability to write JavaScript functions and solve the “Easy” Coderbyte problems, I went to the Hack Reactor website and applied. The interesting part about the their application was that you filled it out using JavaScript. You got to apply your newly learned JavaScript knowledge to maneuver through the application and finally submit it! Right away, it was apparent that a lot of thought went into the application process, which provided me with a strange sense of relief.

I then received an email asking to schedule my technical interview and an optional “take-home” project. I’m not going to go into great detail about the project because I want to preserve the surprise, but I found it rather challenging and intellectually rewarding at the same time. I was asked to create a simple application using Ajax, which I wasn’t totally unfamiliar with because I have already taken the jQuery: The Return Flight on CodeSchool. Nevertheless, you should expect to spend a good amount of time on StackOverflow asking for help.

Finally, about a week later I had my technical interview. Again I’m not going to discuss the contents of the interview, but I will say that it was not what I had expected. My interviewer, John, was extremely nice and even went out of his way to make me feel comfortable. After a little bit of small talk, he asked me a few questions about some JavaScript concepts and then asked to see how I would apply them. Although I was a bit nervous, I answered the first question correctly and with a little bit of help, I was able to solve the rest of the problems too. I have to say that although the questions were definitely challenging and not something I had done before, the additional prep had paid off.

Final Thoughts

The unique interviewing style at Hack Reactor is telling of their overall approach to teaching. From the beginning of the application process until the final interview, I felt that Hack Reactor placed a great deal of emphasis on applying what you learn! To no surprise, it seems that it’s also the quality they look for in candidates – the ability to pick up new concepts quickly and apply them with little help from the instructors. Ultimately, the format of a 12-week crash course isn’t for everybody and that’s what the interview process is for. However, if you can demonstrate you’re eagerness to learn and the ability to be resourceful, you will undoubtedly get in!


For those of you learning how to code, I put together a curated list of resources that I used to learn how to code which can be found at breakingintostartups.com

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