I applied for Groupon through LinkedIn. Got interview call from recruiter within 2-3 weeks.

Round 1 - Screening

• Started with basic Intro - 2mins
• Created and shared a link to StackBlitz
  • Asked me to open the link and start sharing the screen
• Problem statement explanation and clarifications - 5min
  • Create an SPA performing add, update, delete and list items
  • Framework choice: Angular, Vue and React (I chose Vue)
  • I clarified if :
    • UX should be considered
    • SPA structure related (like if is routing required)
  • A quite basic app was expected
• End of 50mins, he asked me to explain what I did (I'd completed list, add, delete and almost edit)

--3 days later—

Round 2 - Problem solving

• Basic Intro - 2mins

• Shared a google doc link and pasted problem statements.

• Problem 1:
  Given an alphanumeric string, return the list of distinct numbers present in the string.
  Input: "som23era23nd56omstr23ing", output: [23,56]
  Constraint: string length <=10^5

  Gave an approach with two pointers to identify a number in the string a store it in a HashSet of int. (since max length of string <10^5)
  Follow up: Length of string could be long enough to overflow into a practical numeric data type - Used HashSet of string instead of int.

• Problem 2 : https://leetcode.com/problems/group-the-people-given-the-group-size-they-belong-to

• Result - Both the problems were solved with optimal soln

--2 days later—

Round 3 - Design and Arch (FE based)

• Basic Intro - 2mins
• Design a component to drop upload a file on the browser
  • Asked many questions like type of files supported, max size, max count, if there is a rate limiting, resumable upload etc.
  • One tricky question - where will I store the files temporarily during the upload, on the client or on the server - I suggested server, along with a purging/cleanup service approach.

--2 days later—

Round 4 - Hiring Manager

• Questions mostly on handling situations with work load and pressure
• Few of LP related questions - Answered with STAR method

—Recruiter reached out to me with another HM round—

Round 5 - Hiring Manager

• Similar to prev round, this was more of discussion of the work culture followed at Groupon and understanding my style of working etc.

Couple of days later : Got an email with the offer