THE slack INTERVIEW

Looking to land a job at Slack but don’t know what the process looks like?
Well, you’ve come to the right place. Detailed in this post is a look at the timeline of the interview process, preparation guidelines, and what's different or unique about Slack's interview process as opposed to other tech companies.
THE slack INTERVIEW explained




BACKGROUND
In the Slack interview you will face around 8 interviews testing you on: programming ability, technical and architectural knowledge as well as determining how the values Slack cares about fit with your own.
BEFORE THE INTERVIEW




update your RESUME
Make sure you’ve updated your resume and in particular your LinkedIn profile; use deliverables and metrics when you can as they are concrete examples of what you’ve accomplished. Make sure to be as specific as possible.

PREPARATION
Here is our guide on how to prepare for the coding interview with a 12-week plan.
CHOOSING YOUR LANGUAGE

Slack does not require that you know any specific programming language before interviewing for a tech position. However, you should be familiar with the syntax of your preferred language such as Java, Python, C#, C/C++. You should also know some of the languages’ nuances, such as how memory management works, or the most commonly used collections, libraries, etc. Choose one you’re most comfortable with and stick to it.
screen with technical recruiter
After reviewing your resume, you’ll be paired with a recruiter who will be your guide through the interview process at Slack. This will be a 30 minute conversation.
technical exercise - code review
The technical exercise will feature an API design exercise and a code review exercise. This should take around two hours to complete. In this technical exercise, you should put a lot of emphasis on:
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code correctness and code style
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an attention to detail and design
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an understanding of the importance of testing
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security concerns and performance issues
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code maintainability and documentation
screen with Hiring manager
This usually takes 1 hour and is an in-depth conversation about your background, current technical challenges you face and what you’re looking for in your next role. It's best to come prepared with a list of things you'd like to know about Slack.
ON-site interview


In the onsite interview, you will meet with about 4-5 individuals for about 45 minutes each. The onsite interview focuses on technical and architectural discussions as well as Slack's values.
You won't be asked to solve algorithm questions or write code on the whiteboard (although Slack may use the whiteboard to have you draw out how you envision a system being built).
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There is no need to bring a computer to the interview, nor are there any specific subjects you should study up on. Slack wants to get a good idea of how you think about building and debugging complex systems at a high level, which is not something you can necessarily study for.
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Be prepared for system design and a lot of behavioral and technical questions mixed in. Don't expect a lot of LeetCode style. You'll want to draw a lot on your past experiences and work to do well in this interview.
THE OFFER / NO offer

From on-site to offer will take about another week or two. This is so management can either evaluate other candidates or to draft up your offer letter along with other logistics.
In the event that you don’t receive an offer, you’ll most likely have to wait six months to a year to re-apply. Don’t expect any feedback after your interview, but you can conclude that you either didn’t have enough experience or that it just wasn’t a fit culturally.
If you do receive a job offer, the hiring manager will call you to discuss salary, start date, etc.
what's different
Code review exercise
Here you will be given a section of code and asked to comment and debug. You will have around two hours to complete this section and is one of the most important sections in the interview loop. Slack says, "We cannot emphasize enough that the coding exercise is the most important way for us to evaluate your technical skills."
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No whiteboarding
Whereas a lot of companies use whiteboarding as an effective way to judge your programming skills, Slack feels like it doesn't accurately depict how you face everyday challenges. Yes, you may be asked to do some whiteboarding for drawing out a system, but you won't have to reverse a binary tree and questions of that nature.
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No LeetCode
Again, a lot of the FAANG companies out there will test you on LeetCode style questions. At Slack, they want to give you questions that you'd most likely face on a day-to-day basis. You may be asked to implement a feature or tradeoffs and drawbacks to certain approaches.
Need help preparing for the interview?
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Check out the Definitive Interview Prep Roadmap,
written and reviewed by real hiring managers.