Questions You’ll Be Asked In The Start-Up Interview

After my second layoff from my second start-up earlier this year, I was looking for yet another startup opportunity. Luckily, I received a lot of responses from start-ups that I applied to on AngelList, and thus had a considerable amount of interviews; enough that the idea of documenting some of my interview questions came to mind.

With that being said, I’ll get straight to the point.

Below is a list of many of the interview questions that I was asked, as a job candidate, during my start-up interviews. The reason I documented these interview questions is because I was hoping that it would be helpful to fellow software engineers like me who are looking for work in the start-up space or the corporate space, or even any type of tech job. At least, I knew it would be helpful for me to read this kind of thing, because this is the kind of stuff I search for on the web to improve as a developer! So, if others feel the same way, it may be helpful for them to see it too.

To be clear and transparent: 
- I’m a software engineer; someone who builds apps. So most of the questions below would be most useful to software engineers.
- I don’t remember every single question I was asked. This is just a list of the ones I remembered enough to document after each of my interviews. 
- Some questions were asked specifically because of the skills and work that I emphasized in my resume and LinkedIn profile.
- Many (if not all) of the questions below are paraphrased and shortened so that it’s applicable for any startup interview.
- I did not interview for a single corporate job, so you will be seeing only questions in here that start-ups asked me.
- I interviewed with CEOs, junior software engineers, senior software engineers, product managers, DevOps engineers, internal recruiters, external recruiters, and other types of co-founders. Thus, these types of questions can come in any stage of the job interview; at least, for the start-up interview.

Feel free to study these questions, because you’ll probably come across a lot of the same ones, or very similar ones. The one tip that I’d like to share, that seems to have helped me, is that you want to structure each of your answers in such a way that your interviewer(s) sees the value that you can bring to their team, their product, and their culture. Because remember, if a company is hiring, they need help. How would you be the most helpful and valuable, compared to other candidates applying for the same job?

General Questions

- Tell me about yourself (variations)?
- What was your biggest challenge and how did you overcome it?
- Have you ever had a disagreement with a co-worker or a boss? If so, how did you handle it? If not, how would you handle it?
- What was the best project you’ve worked on? 
- Where do you see yourself in 5–10 years? 
- Where do you see yourself in 10–15 years? 
- You currently work for ______, so why are you looking for a new opportunity? 
- Would you be open to learning how to ________? 
- What are you looking for in terms of salary? What about equity? 
- Describe your experience working at _______. 
- What are you looking for in your next opportunity? What would your ideal opportunity look like? 
- What interests you about our company? 
- Did you get the chance to look at our app?
- Why do you prefer start-ups over larger, more established companies? 
- What are your hobbies? What do you like to do in your free time? 
- Where do you currently live? 
- Describe the work you did on some of your GitHub projects.

Technical Questions

- What languages and frameworks are you most proficient in? 
- Have you used any JavaScript frameworks? If so, what have you worked on? 
- What was the process for building and deploying new features at your current job? 
- Do you have experience using __________? 
- Have you worked on any side projects? If so, could you describe them? 
- How was the testing of features handled at your current job? 
- How did you handle the process of image uploading at your current job? 
- Do you have experience writing raw SQL? 
- What kinds of reserved keywords could be used in a SQL SELECT statement
- What is the difference between VARCHAR and TEXT? 
- What is the difference between INT, TINYINT, MEDIUMINT, and BIGINT? 
- What column types did you use for your primary and foreign keys at your current job? 
- I have a random number between 1–100,000. How would you go about guessing what number I have in mind? 
- Why is the 32 in (2 ^ 32) such a relevant number? 
- What is the run time of the code you just wrote? 
- What is the memory complexity of the code you just wrote? 
- For the code you wrote, how would you improve the run time? 
- What kind of logic would you put inside a Ruby on Rails model? 
- How did you design the Ruby on Rails API at your current job? 
- What 3rd Party Services did you integrate into your current job? What others have you used for other purposes? 
- What Amazon Web Services products have you used, and what for? 
- How is it that many products of Amazon Web Services are scalable? How do they handle scaling? 
- What types of scaling problems are there? 
- What is a regex? 
- What memory or caching techniques do you have experience with? How and why did you use them? 
- Did you use webhooks at your current job? If so, describe what they were used for and why. 
- In what situations would you use AJAX, and not use it at all?

Skype/Whiteboard Questions, Take Home Projects

- Given the following situation, how would you design the database schema and relationships? 
- How would you implement a File System that contains Files and Folders, that have similar properties and perform similar procedures? 
- Write a program that performs the functionality of the Bucket tool from Paint. 
- Write a spell checker program using that reads a large file of dictionary words, takes input from the user, and spits out the correct auto-correct suggestion (or no suggestion if applicable). 
- A user can have one profile picture and a product can have many pictures. How would you design the database schema for this situation?

Computer Science Concepts

- Run Time Complexity 
- Memory Complexity 
- Hash Tables 
- Arrays 
- 2D Arrays 
- Singly Linked Lists 
- Doubly Linked Lists 
- Binary Search 
- Caching 
- Memory 
- Object Oriented Programming (Interfaces, Inheritance, Abstract Classes) 
- Regexes 
- Powers of 2 
- Background Processing 
- Amazon Web Services 
- Heroku 
- Continuous Integration (CircleCI, TravisCI) 
- Creating Database Schemas 
- Relational Databases (many-to-many/one-to-many/one-to-one relationships) 
- 3rd Party API Integrations (ex. Twilio, Stripe)

As a software engineer, what other questions have you been asked in your interviews that would be helpful for other software engineers to study? Feel free to post them in the comments below!

P.S. I’m currently a Co-Founder / CTO for Jobox, and want to connect with other fellow technical co-founders by creating a Facebook group. If you’re interested in meeting other technical co-founders, learning from each other and helping each other through the struggles of building a great technical product and company, please feel free to respond to me, send me an email (, or tweet me @JourdanB21!