Imagine you are entrusted to expand the working zone in a given city. What data would you look at to decide where its best to expand to?

If you were to decide what country to expand Glovo into, what criteria would you use to do it? Consider unit economics, potential for growth, competition… Choose one country.

Build one SQL query to create a cohort of Signup to First Order and show the result. The objective of this cohort is to see, out of the users that signed up in Week N, how many did their first order in Week N+1, N+2, N+3... As an input, you have 2 tables : - one with user_id, signup_timestamp - and a second one with user_id, order_timestamp Make it scalable.

The Wall Street in New York is known for its breathtaking skyscrapers. But the raining season is approaching, and the amount of water that will fall over the buildings is going to be huge this year. Since every building is stuck to the buildings to its left and to its right (except for the first and the last one), the water can leak from a building only if the height of the building is higher than the height of the building to its left or to its right (the height of the edges of Wall Street is 0). All the buildings have the width of 1 meter. You are given the heights (in meters) of the buildings on Wall Street from left to right, and your task is to print to the standard output (stdout) the total amount of water (in cubic meters) held over the buildings on Wall Street. Example input: heights: [9 8 7 8 9 5 6] Example output: 5