The application was submitted online. The entire process took three weeks, and they were extremely efficient and professional throughout.

First-round was an online programming test, including dynamic programming questions and a sorting algorithm.

The second and third rounds were technical interviews including stats, math, ML, and programming questions.

Stats:

1. There are 25 mechanical horses and a single racetrack. Each horse completes the track in a pre-programmed time, and the horses all have different finishing times, unknown to you. You can race 5 horses at a time. After a race is over, you get a printout with the order the horses finished, but not the finishing times of the horses. What is the minimum number of races you need to identify the fastest 3 horses?

2. What is the probability of passing through a node in a directed graph?

Math questions:

1. Given the correlation C(A,B) and C(B,C), what is C(A,C)?

ML questions:

1. Explain how neural networks work.

2. Three solutions to solve the high variance, low bias problem.

3. Explain backpropagation and the mathematical explanation of it.

4. Why CNNs work well for computer vision.

5. Random forest.

6. The difference between KNN and K-means.