I went through several steps: First a take home case test, it required several hours - maybe 5-10hours. The test was not difficult, it was composed of open questions where you could develop a lot. I interviewed with the "chief of data science?" and CTO. It was somewhat disorganized but at least the HR person apologized for the disorganization when they told me I would not be selected. Interview questions were pretty standard: How to train models, talk a bit about the different models, how to avoid over-fitting...

Call with human resources to understand culture fit, align salary expectations, and describe the company and position. Technical Assessment focused on data exploration, visualization, machine learning, natural language processing, and error analysis.