Since the job location is Beijing, HR required to go to the site for an interview after communication.

One side (spot side)

Since most of the principles of the field need to be explained by hand.

  1. Supervised learning unsupervised learning what difference, word2vec belongs to what type

  2. XGB, GBDT what difference

  3. L1, L2 regular principle, difference

  4. How to use L1 regular in XGB

  5. How to implement list in Python

  6. What’s the difference between List dict

  7. Sort dict by hand

  8. Introduce the project, ask some more from the project


Second interview (on-site interview)

The second eldest brother is temporarily called, did not read my resume, on the resume of the project to discuss, discuss the way to achieve.


Three sides (site side)

  1. To introduce myself

  2. Introduce the project

  3. Boosting Bagging Stacking Principle

  4. Stacking blending difference

  5. Analyze why XGB is used (hint, compare from feature dimensions, sample dimensions, etc.)

  6. The judgment method of overfitting

  7. How to solve overfitting

  8. Probability problem X is a random variable that produces 1,1-p and 0 with probability P, and generates 1-n numbers with equal probability X

  9. Handwritten code merges two sort linked lists


Four sides (field side)

  1. To introduce myself

  2. Introduce the project

  3. The KTH largest number in the handwritten code array

  4. Time complexity of constructing heap


Five intersecting surfaces (video surfaces)

  1. To introduce myself

  2. grades

  3. Key-value data structures in Python

  4. How is the dict base implemented

  5. How to resolve hash conflicts

  6. Examples of unsupervised learning

  7. Explain the K-means principle

  8. Distance calculation method

  9. How to choose a supervised learning model

  10. Scenario questions know all the information and recommend restaurants to users

  11. Algorithm problem two 300G large files, find the intersection of two files


Six HR interviews (telephone interview)

  1. To introduce myself

  2. What offers did you get? Why did you choose Ali

  3. What are the pros and cons

  4. What is your personality? What are your weaknesses

  5. What did you learn from the study? What did you learn from the interview

  6. What are the salary requirements


Seven director’s Face (site face)

The director interview was the most difficult in the history, and the whole process was very confusing. Every question was not answered until the interview lasted about 2 hours.


  1. Project introduction
  2. I will introduce the paper in detail. My thesis direction is traffic. I have a brief discussion on the second interview with the interviewer, and the director asked me to introduce the innovation points one by one
  3. The introduction of the competition, the questions are from the competition, the project
  4. Analyze the principle of XGB in detail, how to choose the splitting point, why to use the second order Taylor expansion, how to express the regular term in XGB. L1, L2 regular difference (I used probability and optimization theory analysis, the director asked me to explain why L1 sparse from gradient descent),
  5. How to find the gradient with L1 regular. XGB, GBDT difference, GBDT why gradient, gradient with what benefits. Finally, I asked about the division of labor in the team.
  6. Algorithm problem array and maximum subsequence


Lots of details. That’s about it. Hope you all find your dream job ~~

Meanwhile source | cattle