After submitting my resume, I was contacted by a recruiter. The process consists of two rounds of interviews.

The first round is one technical interview with two engineers. It covers CS basics, a project discussion, and simple coding questions.

Four separate interviews make up the second round. Each one is an hour long. The order of interviews isn't fixed, and you may spread them out over two days. The interviews are:

• Behavioral ("values")
• System design
• Programming
• "Data"

Getting feedback in-between the interviews and booking the next round took a lot of time and emails.

Round 1: Discuss a project related to data engineering. Challenges, conflicts, what to do differently.

Round 1: Technical questions

• Common data structures and algorithms (search in sorted list, search in linked list, red-black-tree)
• How would you implement a priority queue?
• HashMap collision resolution strategies
• Examples of probabilistic data structures, advantages
• Difference between functional and imperative programming.
• How would you represent a graph in-memory?
• Difference between columnar and row-based databases.
• Difference between inner and outer joins.
• Explain MapReduce.

Round 1: Coding Question

• Fibonacci (iterative and recursive)
• Simple SQL on a single table (group by and accumulate)

Round 2: Coding

• Calculate the median of a window of values over an infinite data stream.
• And a second data question I don't remember.

Round 2: Data

• You are given a dataset of song "plays" and metadata (song, artists, etc.).
• Design a data solution to calculate the top artists per country.

Round 2: System Design

• Similar to data, design a "weekly wrapped" feature (top 50 songs per country per week).

Round 2: Values

• Standard behavioral with hiring manager.