1. Cracking the Coding Interview Advice and Strategies for Software Engineering and PM Interviews McDowell | CareerCup.com | Palantir Oct 2012 Gayle Laakmann McDowell Founder / CEO, CareerCup.com Author of The Google Resume and Cracking the Coding Interview

2. Technical Skills Behavioral Applying Process My Background Software Engineer @ Google, Microsoft & Apple – 3 Years on Google Hiring Committee – Interviewed 150+ candidates Founder of CareerCup.com Author – Cracking the Coding Interview – The Google Resume McDowell | CareerCup.com

3. Technical Skills Behavioral Applying Process Slides Posted Online posted at: www.technologywoman.com Click “Speaking Engagements” McDowell | CareerCup.com

4. Technical Skills Behavioral Applying Process EvaluationStructureApplyingExperienceResumeSoft SkillsPreparationInterviewTech SkillsPreparationInterview McDowell | CareerCup.com

5. Interview Process McDowell | CareerCup.com

6. Technical Skills Behavioral Applying Process Big Company Evaluation (Devs) McDowell | CareerCup.com Testing aptitude, not knowledge

7. Technical Skills Behavioral Applying Process Start-Ups (Devs) “Hit the ground running” – Do you know “their” technologies? Entrepreneurial – Have you started things? – How much direction do you need? Personality – Will you fit with the team? McDowell | CareerCup.com but… it varies! but… it varies!

8. Technical Skills Behavioral Applying Process PMs (Microsoft) & APMs (Google) Communication Skills User-Focused Thinking Passion for Technology Analytical Skills Technical Skills (position dependent) McDowell | CareerCup.com

9. Technical Skills Behavioral Applying Process How You Are Judged McDowell | CareerCup.com How did you do RELATIVE to other candidates on the SAME question? How did you do RELATIVE to other candidates on the SAME question? … it’s about how quickly you solved it relative to other candidates. It’s not about how quickly you solved the problem…

10. Resumes & Application Process McDowell | CareerCup.com

11. Technical Skills Behavioral Applying Process How to Get an Interview Build something! Make a kick-ass resume McDowell | CareerCup.com Got a weekend free? It’s really not that hard.

12. Technical Skills Behavioral Applying Process How We Review Resumes 1.Pull resume out of giant stack 2.Spot-check: company names, positions, projects, schools. 3.Skim bullets for coding / impact McDowell | CareerCup.com Interview Reject 4.Go to next resume & whine about how many more you have left. “Glanced at,” not read. 15 – 30 seconds

13. How CS Resume Should Look Short (1 – 2 line bullets) 3 – 4 Projects Courses & independent Finished or unfinished 3 – 4 Projects Courses & independent Finished or unfinished List of Technical Skills Short! Cut the “fluff.” List of Technical Skills Short! Cut the “fluff.” GPA if at least 3.0 max (in-major, overall) GPA if at least 3.0 max (in-major, overall) One Page Only! Unless > 10 years exp. One Page Only! Unless > 10 years exp. A Real Resume Format with organized columns A Real Resume Format with organized columns Focus on Accomplishments not responsibilities Focus on Accomplishments not responsibilities Observe: No Objective! Objectives / summaries are almost always useless. Observe: No Objective! Objectives / summaries are almost always useless.

14. Behavioral Questions McDowell | CareerCup.com

15. Technical Skills Behavioral Applying Process Goals of Your Answer Answer the question. Deliver a good answer. Communicate well. – Nugget First – S.A.R.: Situation, Action, Result McDowell | CareerCup.com

16. Technical Skills Behavioral Applying Process Preparing for Behavioral Qs Create Preparation Grid for Projects McDowell | CareerCup.com OS ProjectAmazon Intern. Enjoyed Hated Most Challenging Hardest Bug + Behavioral Grid [for PM & less tech. roles]

17. Technical Skills Interview Prep McDowell | CareerCup.com

18. Technical Skills Behavioral Applying Process How to study Study the basics – Complex algorithms generally unnecessary. Practice solving questions – Don’t memorize! – See: CtCI & CareerCup.com Push yourself! Write code on paper McDowell | CareerCup.com

19. Technical Skills Behavioral Applying Process Data Structures How to implement When to use (pros / cons) McDowell | CareerCup.com Linked ListsStacksQueues TreesTriesGraphs VectorsHeapsHashtables

20. Technical Skills Behavioral Applying Process Algorithms Implementation Space vs. Time Complexity McDowell | CareerCup.com Quick SortMerge Sort Tree Insert / FindBinary Search Breadth-First Search Depth-First Search

21. Technical Skills Behavioral Applying Process Concepts Not just a concept – know how to code! McDowell | CareerCup.com Threading Big-O Time / Space Memory Management Recursion Probability + Combinatorics Bit Manipulation

22. Technical Skills Mastering the Interview McDowell | CareerCup.com

23. Technical Estimation Product Design Types of “Serious” Questions 1.Product Design Questions 2.Estimation Questions 3.Software Engineering Questions – Coding & Algorithms – Object Oriented Design – Scalability McDowell | CareerCup.com

24. Technical Estimation Product Design Product Design Questions How would you design an calculator for the blind? How would you design an calculator for the blind? Design an elevator for a building. Pick a Google product. How would you improve it? Pick a Google product. How would you improve it?

25. Technical Estimation Product Design Product Design Questions: Why? Communication & Structured Thinking Ability to understand the user Creativity Business instincts / skills

26. Technical Estimation Product Design Product Design Qs: Approach 1.Ask questions to resolve ambiguity 2.Understand the user 3.Structure the problem 4.Solve piece by piece

27. Technical Estimation Product Design Estimation Questions How many tennis balls can fit in an SUV? How many tennis balls can fit in an SUV? How much money does Gmail make from ads every year? How much do New Yorkers spend on electricity each year? How much do New Yorkers spend on electricity each year?

28. Technical Estimation Product Design Estimation Qs: Why? Problem Solving Basic Quantitative Skills

29. Technical Estimation Product Design Estimation Qs: How to Approach 1.Ask questions to resolve ambiguity – Don’t make assumptions (yet) 2.Outline / Structure Your Approach 3.Break down the components – Assume numbers when necessary – State assumptions explicitly – Round numbers to make your math easier 4.Sanity Check – Do your numbers make sense?

30. Technical Estimation Product Design Technical Questions 1.Ask Questions! – Questions are more ambiguous than they appear 2.Talk out loud – Show us how you think 3.Think critically – Does your algorithm really work? What’s the space and time complexity? 4.Code slowly and methodically – It’s not a race 5.Test your code – And make CAREFUL fixes. McDowell | CareerCup.com If you’ve heard a question before, admit it.

31. Technical Estimation Product Design What does a “good coder” do? Be methodical. Don’t try to rush. Reasonably Bug Free – Thorough testing (and careful fixing) – Check for error conditions Clean coding – Use other functions – Good use of data structures (define own if useful) – Concise and readable McDowell | CareerCup.com

32. Technical Estimation Product Design Types of Interview Questions McDowell | CareerCup.com Coding & AlgorithmsObject Oriented DesignSystem Design “Reverse a Linked List” “Design a Parking Lot” “Design a Web Crawler”

33. Technical Estimation Product Design Types of Interview Questions McDowell | CareerCup.com Coding & AlgorithmsPattern MatchingSimplify & GeneralizeBase Case & Build Data Structure Brainstorm Object Oriented DesignSystem Design

34. Technical Estimation Product Design Algorithm Qs: Pattern Matching McDowell | CareerCup.com Q: Write code to reverse the order of words in a sentence. “dogs are cute” “cute are dogs” Similar to: reverse characters in a string. “dogs are cute” “etuc era sgod” A: Reverse full string, then reverse each word. Coding & AlgorithmsPattern MatchingSimplify & GeneralizeBase Case & Build Data Structure Brainstorm Object Oriented DesignSystem Design

35. Technical Estimation Product Design Algorithm Qs: Simplify & Generalize McDowell | CareerCup.com Coding & AlgorithmsPattern MatchingSimplify & GeneralizeBase Case & Build Data Structure Brainstorm Object Oriented DesignSystem Design Q: Design algorithm to figure out if you can build a ransom note (array of strings) from a magazine (array of strings). Simplify: what if we used characters instead of strings?  Build array of character frequencies. Generalize: how we can extend answer to words? A: Build hashtable from word to frequency.

36. Technical Estimation Product Design Algorithm Qs: Base Case & Build McDowell | CareerCup.com Coding & AlgorithmsPattern MatchingSimplify & GeneralizeBase Case & Build Data Structure Brainstorm Object Oriented DesignSystem Design Q: Design algorithm to print subsets of set. {a, b, c}  {}, {a}, {b}, {c}, {a, b}, {a, c}, {b, c}, {a, b, c} S({})  {} S({a})  {}, {a} S({a, b})  {}, {a}, {b}, {a, b} S({a, b, c})  ? A: Build S(n) by cloning S(n-1) and adding n to the cloned sets.

37. Technical Estimation Product Design Algorithm Qs: Data Structure Brainstorm McDowell | CareerCup.com Coding & AlgorithmsPattern MatchingSimplify & GeneralizeBase Case & Build Data Structure Brainstorm Object Oriented DesignSystem Design Q: There are 10^10 possible phone #s. Explain how you could efficiently implement assignSpecificNum(num) and assignAnyAvailableNum(). Array (sorted)? Too slow to remove num. Linked list? Too slow to find specific num. Hash table? Can’t iterate through free nums. Tree? Ah-ha! A: Store free #s in BST. Remove when taken.

38. Technical Estimation Product Design Coding & AlgorithmsPattern MatchingSimplify & GeneralizeBase Case & Build Data Structure Brainstorm Object Oriented DesignSystem Design How To Solve Algorithm Questions McDowell | CareerCup.com Compare to similar problems. Solve first for a simplified / tweaked problem. Solve for n = 1, and build solution for n = 2. Try to apply data structure to solve problem.

39. Technical Estimation Product Design Object Oriented Design McDowell | CareerCup.com Handle Ambiguity What about the question is ambiguous? Design the Core Objects What are the main objects in the system? Analyze Relationships How are the objects related to each other? Investigate Actions What are the main operations? Coding & AlgorithmsObject Oriented DesignSystem Design

40. Technical Estimation Product Design Coding & AlgorithmsObject Oriented DesignSystem Design Object Oriented Design McDowell | CareerCup.com Handle Ambiguity Is it a single restaurant, or part of a chain? Design the Core Objects Guest, Party, Table, Server, Host, … Analyze Relationships Server and Host are both Employees… Investigate Actions A Party is seated at a Table by a Host… How would you design the data structures and objects for a restaurant?

41. Technical Estimation Product Design System Design McDowell | CareerCup.com Handle Ambiguity What about the question is ambiguous? Make Believe Pretend there wasn’t so much data & solve Get Real Go back to the real problem. What breaks? Solve Problems Solve the issues you just found. Coding & AlgorithmsObject Oriented DesignSystem Design

42. Technical Estimation Product Design System Design McDowell | CareerCup.com Handle Ambiguity Do the words need to be in a specific order? Make Believe Assume everything can fit on one machine. Get Real Must split up data across machines. Solve Problems Divide hash table by file or by keyword? Given millions of documents, find all documents which contain a list of words. Coding & AlgorithmsObject Oriented DesignSystem Design

43. Technical Estimation Product Design Whew! All Done! McDowell | CareerCup.com This is a lot of stuff. Do I need to get everything right? Coding & AlgorithmsPattern MatchingSimplify & GeneralizeBase Case & Build Data Structure Brainstorm Object Oriented DesignSystem Design

44. Technical Skills Behavioral Applying Process This is a lot of stuff. Do I need to get everything right? McDowell | CareerCup.com Evaluation is RELATIVE, not absolute. Evaluation is RELATIVE, not absolute. … it’s about how quickly you solved it relative to other candidates. It’s not about how quickly you solved the problem…

45. Technical Skills Behavioral Applying Process So RELAX! Interviews are supposed to be hard! So RELAX! Interviews are supposed to be hard! Everyone makes mistakes. Everyone! McDowell | CareerCup.com

46. Final Thoughts McDowell | CareerCup.com

47. Technical Skills Behavioral Applying Process After Your Interview Follow-up with your recruiter – No response != rejection You have no idea how well/poorly you did. – Seriously. I know you think you do. But you don’t. Lots of randomness. – So if you fail, get up and try again. McDowell | CareerCup.com

48. Technical Skills Behavioral Applying Process Other Resources Sold Today Signed! {ask to add your name too} McDowell | CareerCup.com CareerCup.com Interview Videos iPhone App Resume Review Mock Interviews today $15 Or, follow me online at… twitter.com/gayle facebook.com/gayle technologywoman.com gayle@careercup.com today $25 5 stars!