Give me 2 minutes, and I'll teach you how Uber computes ETA (not joking): • They represent the physical map as a graph • They compute ETA by finding the shortest path in a directed weighted graph • They don't use Dijkstra’s algorithm because it won't scale with O(n*logn) time complexity • They partition the graph and then precompute the best path within each partition • They reduce the time complexity from O(n^2) to O(n) by partitioning graph • They populate the edge weights of the graph with traffic information • They do map matching to find accurate ETA • They use the Kalman filter and Viterbi algorithm for map matching —— 👋 PS - I wrote an article with visuals of this case study in my newsletter: →

RT @systemdesignone: System Design Interview's RED FLAG list. If you’re making these 5 mistakes… WE NEED TO TALK 😂

@_jaydeepkarale probably both? it depends.

@Dhanush_Nehru thanks a lot

@Abh1navv good for us

@petarivanovv9 yes, this is underrated and often overseen

@dmokafa thank you for sharing, Daniel.

@swapnakpanda true; I think rephrasing what the interviewer can make things simpler.

@InterviewsChat exactly, the best approach is to avoid common mistakes and practice more with mocks.

@techyoutbe hey, thank you

👋 PS - Join 100,000 engineers and get the powerful system design template (it's free):

@svpino AI can't still solve Captcha on most sites.

@RaulJuncoV thanks, I like to start every answer with "it depends."

@swapnakpanda As someone who loves python, thank you