Coding Interviews

Ques: I’m just learning. Do I need to pass those data structures and algorithms questions to get my first job in tech?

Answer: Yes, most likely.

It’s OK to be scared of data structures and algorithms questions. When you first get exposed to them, they are definitely overwhelming. However, if you take the time to study them, they get easier.

So, why do you need to know them?

For most jobs, you will have to show coding proficiency. Every company defines proficiency differently Tests will vary. While some companies may test you on something you may actually do on the job, others may want to test an arcane algorithm that is rarely used in production code (think Google and Meta interviews here). Nevertheless, having a basic understanding of data structures and some algorithms will help you to be a better programmer. Being able to pass coding interviews will help you get a job.

So how do you approach learning data structures and algorithms?

You have options, but first think about your goals, your time, and your money. Make the best decision for you:

  • The most absolute TLDR of Data Structures and Algos I’ve seen so far is Patterns to Master Leetcode.

  • InterviewCake takes common coding challenges and teaches you how to think about the problems. It is really good if you want to take the time to slowly work through everything and build mastery. However, it is not cheap.

  • Some people go hardcore and decide to watch the famous Harvard CS50 course to understand data structures. David Malan is the nearest thing we have to a computer science teaching god. He’s enjoyable to watch and can explain hard concepts easily. David provides an entirely free option via multiple platforms, including YouTube.

  • Udacity Data Structures and Algorithms Nanodegree is great for learning data strucs, algos and how to think about coding problems. However, not only is this a more expensive program than Interview Cake, it also takes way longer.

  • Youtube is a great free option. It may take you a while to find a data structures video that is easily understandable, but they exist and are supremely helpful.

  • Google search, as always, is a coder’s best friend. When you google “data structures and algorithms”, you’ll find a ton of blogs that explain what they are. It may take you some time to find a good blog, but they exist!

  • Neetcode.io. My brother-in-law, Ed, swears by this dude.

Now that you have a basic understanding of data structures and algorithms, you have to practice using them. Some of the aforementioned sites also enable you to practice. Here are some more awesome places to practice:

  • Leetcode has more problems than you or I can hope to get ever get through. Many problems are free! However, I highly recommend getting a monthly plan so that you can:

    • Access all problems

    • Submit your answer as many times as you want

    • See solutions

    • Use the debugger

    • Sort problems by data structure type, algorithm or (BIG ONE) company!

  • Grind 75 is curated Leetcode problems at the pace you set. I wish I could buy this person a steak.

  • Meta’s Careers website, specifically Preparation Hub put together by Gayle Laakmann McDowell herself and Coding Puzzles are particularly helpful. You do not need to be interviewing with Meta to use them. You can

  • Hackerrank is decent.

  • Some people LOVE Codewars with a passion I have not yet come to understand. Maybe I will one day.

  • New sites pop up every day. If you find a good one, let me know. I can add it!

Two last things: While you need to understand data structures and algorithms AND be able to code them, you also need to be able to:

  1. Code answers to questions within a specific time frame (a.k.a. eventually practice your speed)

  2. Explain what you’re coding while you’re coding (a.k.a. practice as if you’re in a real coding interview, find a friend who interviews to mock interview you, or as a last resort pay someone who is an interviewer to mock interview you)