Tech Interview Preparation
Preparing for your interview
We have different types of interview formats: live coding, system design, case studies and a background interview. Depending on the role you're applying for, you may be assigned a different combination of each interview format. The case study format is typically only for data science roles. Each interview section is usually 1 hour long. For all interview types, we try to assess the following skills.
- Accuracy. Your implementation should be correct and working. Being able to understand the big picture is just as important as being able to implement it.
- Timeliness. Even if it's possible to make something work end-to-end, we want to make sure you can complete features in a timely manner. Rushing and making mistakes isn't good, but neither is taking too long to finish a problem.
- Design. Designing a good system may require you to zoom-out and think of how a system works end-to-end before starting a problem. A comprehensible and simple implementation is always preferred over a system that's hard to maintain and explain.
- Communication. Our tech team works often with non-technical people, it's important to keep your communication brief and simple.
For your interview, ensure that you are in a quiet place with reliable internet connection. Do not record any parts of the interview and do not divulge interview questions to others.
Live Coding Interview
During this interview you will build a small system based on some requirements given in the interview.
You will be expected to demonstrate that your code is tested and working end-to-end by writing and executing code inside coderpad. You’re free to use the internet to search for language or runtime specific information. You can not use a service which writes code for you. You can not write code in an IDE and then copy and paste it into CoderPad. During this interview we will be using a video call and a CoderPad link which will be shared with you at the beginning of the interview. You are free to use any programming language supported in CoderPad. Choose the programming language that you are most comfortable with. Before the interview read the For Candidiates section on Coderpad. Please prepare for the interview by using the coderpad sandbox by writing, executing and testing code.
An example prompt might be the following
Implement a class or system which represents a digital book. We would like to implement the following methods
- Go back one page
- Go forward one page
- Get the current page number
- Get current page text
- Determine if the current page contains a case-insensitive string
- Implement a library system or class which can store many books
- Given text as an input, return an array of books where the author name matches the argument text
System Design Interview
During this interview we will be using a shared google doc which will be sent to you at the start of the interview. Please use the google doc to communicate and diagram your ideas. You may be asked to write pseudo-code, clarify your ideas, or be asked about specific implementation details. In this section you will be designing the primary components for a software system. You are free to design the system as you like. You may be asked questions related to the following concepts: Entities, how to persist them, APIs, HTTP, in-memory storage, on disk storage (SQL / noSQL), mobile, web clients, caches, devops, design tradeoffs. The system will be described to you during the interview.
Case Study
The case study interview is usually only for Data Science candidates. You will be given a take home assignment which outlines a problem statement. A follow-up interview will be scheduled to present your results. You will usually be presenting to both a technical and non-technical audience. Good presentation and communication skills are key to succeeding in this interview. Candidates may tools like google sheets, python libraries via a jupyter notebook or other tools to examine the data and create visualizations in their presentation.
Background Interview
The background interview is a less formal interview type which allow interviewers to learn more about your background. You may be interviewed by 1 more than interviewer who may work in a non-technical role. While other interview types are highly technical, this interview focuses heavily on communication skills.
