They used a "working interview" process, they had several candidates overlapping, doing complicated tasks with no follow up. It was paid, but chaotic and seemed to be an ineffective measure, overall.
First, an online interview to get to know each other
Then, an online time limited data science exercise to evaluate knowledge of python, dataframes and data analytics/ML
Then another more interview like meeting with specific questions on the topic of data science
Interview questions [1]
Question 1
Explain to a non-tech customer what F1-measure is ?