I applied for a Data Engineer position at the beginning of March. The process took over three months to conclude, as I went through the full cycle to the end.

1. Logic test with pattern recognition puzzles that took about 15 minutes to complete.
2. Typical screening interview with an HR representative.
3. I was then sent a link for an online skills-based test. In my case, this was a set of three SQL problems involving basic and advanced join techniques, CTEs, and the use of analytical functions and methods, such as windowing. Overall, the problems weren't too difficult if you have a solid grasp of SQL. While they don't give you a time limit for the problems, there is an estimate of how long it will take, and they definitely do take that into account. How much weight is put on that, I'm not sure.
4. For some reason, I had to do the same logic test that I had completed initially, only this time with a person from HR watching me on camera.
5. Technical interview with a member of the engineering team. This was a two-part interview: firstly, to discuss possible improvements to my SQL code from the skills test. Up next was an "onboarding" exercise where I was tasked to take a project I had worked on and explain the design and architecture choices to the interviewer. Additionally, I had to explain various issues encountered and my solutions for them.
6. This was supposed to be a behavioral interview with the head of the data domain but ended up being more of a chat around the teams within the domain and where I would possibly fit in.

After this process, I was told I would be flown out to Stockholm for the second round of interviews. The process takes a whole day.

1. Whiteboard session with a team lead based on two case studies to architect a data pipeline and create a data model for each case.
2. Interview with the head of the data domain again, pretty much the same as number 6.
3. Tour of offices and lunch with some team members.
4. Two wrap-up interviews with HR personnel.

Overall, the experience was good. The interviews were fairly relaxed but at the same time designed to test your knowledge and skills while avoiding gotchas and tricks designed to throw you off. The process is super lengthy, though. After each step, I would usually have to wait at least a week for someone to get back to me to set up the next interview for the following week. Be prepared should you decide to invest your time and emotions into the process.

Build a data pipeline using open-source technologies to produce a report for Exco. You are limited in terms of budget (i.e., no expensive on-premise or cloud solutions).

Scale the pipeline to include streaming of real-time events, increased frequency of report generation, and using more advanced data storage and warehousing/data lake solutions.

Create a star schema data model to produce the minimum data required for a report.