Role - Backend developer
Location - Gurugram
Experience - 3 years 9 months

Round 0 - Online Assessment
4 questions on Code signal platform - all 4 had to be solved correctly. 2 were easy, 1 was medium, 1 was hard

Round 1 - Technical Round 1

• How did you optimize the running time of your projects?
• Which database did you use in your project and why? Why not NoSQL Database? Difference between SQL and NoSQL.
• How does NoSQL support horizontal scalability? Tell about ACID and CAP theorem. Are consistency and availability both possible simultaneously?
• Tell about isolation levels and indices in SQL database. Advantages and disadvantages of indices.
• What is idempotency in API and how can it be achieved? Difference between Put and Patch.
• Difference between optimistic and pessimistic locking.
• Time complexity of insertion/ accessing an element in a BST.
• DSA question - https://leetcode.com/problems/max-consecutive-ones-iii/description/
  Verdict - Positive

Round 2- Technical Round 2

• Find maximum path sum in any tree on a downward path (full working code), follow-up question - what if the path can be in any direction, not necessarily downwards
• How will you avoid double payment by a user while designing the APIs in a payment system?
• Suppose a user is performing an action from multiple devices, for eg. ticket booking, but that action should be reflected only once- how will you handle this?
• What would you do if redis cache memory is exhausted?
  Verdict - Positive

Round 3 - Technical Round 3

• Project Discussion, Follow Up Questions
• Discussion of LLD of Ticket Master Website - requirements specification, entities, database schema design, APIs design
• Discussion on HLD of the system
• How to handle concurrent bookings?
• In which tables is it advisable to introduce indexing?
• How to make searching of any meta data faster? How does Elastic Search sync with the database?
  Verdict - Positive

Round 4- HR Round - This round consisted of background check and basic HR questions.

Round 5 - Techno-Managerial Round
This round was a mix of technical and managerial questions.

• Discussion on resume and past projects with follow up questions
• Tell a situation when you got a critical negative feedback
• Tell about a situation when you pushed your limits
• Tell a situation when you had disagreement with teammates
• Reason of switch and expectations with the new role
  Verdict - Positive

Overall - Selected.