Facebook @DataEngineer
How prepare for facebook Data Engineer interview. What are the topics to cover
It actually is very straight forward so don’t overthink it, both phone and on-site. The code part can be solved with basic structures and controls like has tables, loops, arrays, lists. The SQL as well just keep it straight forward. Think about what your execution plan would be like and minimize the number of times you’d hit a table. I’m not sure what SQL dialects you’re used to but for prep make sure you focus on ANSI standard code and not a specific language implementation. The nice thing about the on-site is that it feels like solving real problems albeit simple ones. E.g. you’ll talk about a company or a new product/feature, design a theoretical data model for it, define some useful metrics to answer business questions, write SQL to get said metrics, write a code based streaming version of those same metrics.
What do you mean by write a code based streaming version of those same metrics?
So let’s say you had a sample table and the metric you had was calculate the average duration of each step by unique ID. So you write some SQL to do that. Then it’d be like ok now instead of a table you had a stream of events with an ID, step, and time stamp. Write a method that calculates that same metric in your code of choice like python or scala.
All questions they ask are already on Glassdoor. Make sure your basics are clear especially data structure and SQL.