📗 Notes

Notes on a talk by: Marcelo Cortes at Indigo Fair

This talk will be focused on full-time interview rather than coop interviews

The Interview Basics

Different Interview Types
Coding (Solving some basic problem, efficiently and w/ good communication)
Algorithms (won't need to code directly (most times), white-boarding, done by Google and FB)
System Design (Example Google asks: how would you design the backend of Gmail)
Selling (trying to get you to work at the company, a final step)
This talk will be focusing on the coding interview
Different Coding Interview Environments
Phone (rare but difficult, relies on verbal explanation)
Video Conference (0.5-1h, using a code-share, watching you live)
Onsite with a remote interviewer
Onsite with a whiteboard (conventional, requires good explaining skills)
Onsite pair programming interview (most common, dedicated computer for you)

The Interviewer's POV

What they look for?

Can you communicate your ideas effectively?
How well do you know the language (syntax, methods, basics)
Are you coach-able? Are you listening to feedback, are you receptive?
How familiar are you with the tools? Do you know the IDE? Editor?
Are you practicing and putting effort to better yourself?
Do you know algorithms?
Are you thinking about the long-term (runtime, memory, etc.)?
Can you code? Recursion? Iteration? Data structures?
Do you care about code style? Naming? Strategy and approach? Do you keep patching edge cases or do you think ahead?

Coding Interview Structure (60 minute example)

00..02: Quick intro and get setup
02..05: Describing the coding problem
05..15: Discussing the algorithm and possible solutions
You don't want to jump into code, this is where you ask questions, and understand the problem you want to solve
15..55: Coding the actual solution
55..60: Candidate's turn to ask questions
This is where you show that you care about the company and the work they do

A Simple Problem

Given a list of words, find the maximum common prefix between any two words on the list.

 words = [
   'electronics',
   'compact disc',
   'alphabet',
   'compass',
   'giraffe',
   'electricity'
 ]
 prefix = 'elect'

Questions to Ask

Other Points

Mention it and quickly explain how the algorithm solution works to show you know it.
ex: "Compare each word to each other, and store the longest prefix as a variable. Once all words have been compared, return the variable"
Can We do Better?
Almost always there is a better solution
Best way to get good at algorithms is practicing (Check out TopCoder)
Always ask questions such as;
- Does sorting input help?
- What data structures could help? Set? Hash map? Tree?
- Can I collect data to help in a first pass?
Define the Interface
- Method, Variable Names, Process, Comments
- Validation Framework (5 min)
- Write simple test cases (including an All Tests Passed! message)

Note: A trie/tree is usually the ideal solution for most 'prefix' questions

Your Time to Interview

Don't Ask
- how did you do in the interview, your solution, other Solutions
- better ways to solve the Problem
- salary, bonus, options, etc.
Do Ask
- About the company, team, the culture, the product, the job
- The tools, the work environment, the mission, the vision
- How the team prioritizes tasks, etc.

Conclusion

Practice a lot! Be prepared, stay calm and perform well.
Arrive early, have your environment ready. (Don't waste time on setup or updates)
Communicate well and often. Ask questions. Keep talking.
Talk about your code while you write it.
Let the interviewer in your head, communicate properly with them
Have a strategy. Discuss options, If stuck, ask for advice. (They want to help you, write pseudo code, explain why you're stuck, let them assist you)
Make sure you understand the problem. Write a simple test framework. Start with a test case.
Try to have fun!

Q/A