How to Prepare for the Hack Reactor Technical Interview

Because I realize how many people I am indebted to on the web for all their help regarding Hack Reactor admissions, I thought it would be nice for me to do the same. Also, most of the resources online seem to be a bit outdated so maybe this will give a clearer picture of what it means to get from “0 to 20.”

Where I Started From:

I had literally 0 programming experience when I started. Z-e-r-o. I had taken an AP Computer Science class back in high school where I believe I learned some Java, but all of that went down the gutter years ago and I also did so horribly in that class I was scarred. On top of that, I was a business / liberal arts major at Cornell so I hadn’t even touched anything remotely technical. Once I had to open up my terminal shell for some program I was installing and was getting anxious because I thought you could blow up your computer using it (which definitely can happen... DON’T TYPE RM -RF).

So then you might be asking, “How in the world did you get interested in something you used to hate?”

Programming was so foreign to me I often exoticized it. I was always jealous of the software engineers who got to work on the product and make it cooler. I thought it was never a possibility for me to until I saw a couple connections on Facebook writing about their amazing experiences at coding bootcamps and how they had turned their lives around. My curiosity was piqued.

What Resources I Used:

  • I started off with Codecademy and Code School. These are great resources to hold your hand and learn Javascript if you’ve had very littler or no experience programming.
  • I bought a subscription to CoderByte and started doing all the easy coding challenges. The easy were not so easy after all and there were many moments of despair. Some of the easy challenges are still not very easy today… Also go ahead and make an account to Codewars, Codefights, and LeetCodes.
  • Hack Reactor suggests you know Eloquent Javascript chapters 1–5. I previously used the much expanded annotated version, but that has since been shut down and Gordon has decided to start his own programming course called Watch and Code instead.
Give yourself several months of getting familiar with these concepts. Try to code everyday or at least once every couple days. It was really difficult for me with a full time job and an active social life plus being involved at church. But don’t give up! If a guy who has basically never touched programming before in his life can do it, you most definitely can!

The Admissions Challenge and Technical Interview:

Hack Reactor tells you that you must master callbacks to be able to pass their admissions test. These two articles from Javascript.isSexy are good to know conceptually:

  1. Callbacks —
  2. Closures —

At a certain point I knew I should just go ahead and try the admissions challenge. The challenge itself is very easy and anyone with basic knowledge of Javascript syntax can get through it. I then signed up for the technical interview. The technical interview though is a different beast.

The Suspense:

I waited about a week and a half for a letter from admissions. As suspected, I didn’t get in. The technical interview was very difficult for me. I just didn’t have enough experience with Javascript syntax or callbacks at that point. I was pretty disappointed, but I knew I the experience would be helpful.

At that point, I was given what was called a “conditional acceptance” with the option to wait a couple months to retake the interview or take the Hack Reactor Remote Prep Course. I chose the later as I knew this would be a helpful course and also you can put all your admission cost for the prep course towards the actual bootcamp tuition if you get in. It seemed like a no-brainer to me.

The course was 8 weeks long and very helpful. I’ll save the writeup for Remote Prep for another Medium post. As soon as the course ended, I signed up for another technical interview slot.

Here We Go Again:

And this time I was cruising and doing so well until the very end where I got stumped on this one callback problem (know your callbacks!). I was so upset because after the interview was over I retried the problem and was able to solve it. The combination of nerves and seeing something unfamiliar completely unsettled me. My interviewer told me I had done so well until the last problem and he seemed genuinely upset for me.

I knew I didn’t get in… And a couple days later, I was offered another “conditional acceptance,” but this time with access to a Hack Reactor mentorship program. This is basically like office hours and one-on-one coaching with a Hack Reactor mentor. I was amazed by the amount of resources Hack Reactor poured into trying to help people to learn to code better. I actually ended up just reapplying one last time after another week of study. I couldn’t even take advantage of the mentorship program because none of the hours worked for me.

I knew was all or nothing at this point. If I didn’t pass this time, I wasn’t meant to become a cool nerdy programmer working on innovative products. I would give up on my pursuit.


But this time was different — I was much more confident going in. I had worked on a bunch of different resources to get me ready for callbacks and closures. I had reread and done the exercises in Eloquent Javascript like a billion times at this point. Rewriting different Javascript libraries like Underscore.js were very helpful as well. And of course, I crushed the interview my third time. I got my acceptance letter a couple days later.

If I can do it, then you can too! Programming requires perseverance and drive to learn as much as you can. I’m actually drowning in all the pre-course homework and lectures that were given to our cohort as I am typing this out. In fact, I should probably go do homework now. Until next time…

What are you waiting for? Go ahead and apply: