Free open pleasant conversation where you're asked to tell about yourself and your experience, dug more into practical experience in code and specifically calibration and normalization and machine learning. Said would continue with a home task.

The first step was a 10-15-minute phone call. They asked about my background and experience and talked a bit about the company. It's a small startup with about 10 employees. They work on diverse data projects for their customers. The next step was a home assignment. it took them about a week and a half to get back to me. They were pleasant and polite.