Edit 1: Got the offer from Meta for E4. Will be joining next month. All the best everyone.
Hi Everyone, last week, I had my virtual onsite with Facebook/Meta for the Software Engineer (E4) position.
I'll try to give back to community as much as I can while honoring the NDA.
Phone Interview (45 min):
Virtual Onsite:
Coding Round 1(45 min):
2 LC medium questions. 1st question is not on leetcode. Discussed the approach with interviewer first. Did the dry run on the given examples. Got the go a head from the interviewer to code. Coded the solutions. Discussed the space and time complexity. And discussed the edge cases as well to test the code. Interviewer seemed satisfied.
First question expectation - TC - O(n), SC - O(k)
Second question expectation - TC - O(logn), SC - O(1)
Coding Round 2(45 min):
2 LC medium questions. 1st one is not present in the leetcode FB tagged questions. Discussed the approaches with the interviewer, got the go a head to write the code. dry run on the given examples. Added a few test cases to test the solution. At the end, discussed runtime and space time complexity.
First question expectation - TC - O(n), SC - O(1)
Second question expectation - TC - O(n), SC - O(1)
We finished this round 5 -10 min early, so interviewer asked some follow up questions.
Q: Optimizing the solutions in memory constrained environment. How would it impact your algorithms?
Behavioral Round(45 min):
This round was mainly focusing on the leadership, cultural fit, team collaboration, conflicts with Manager, Going above and beyond to understand the consumer/customer needs. This round was pretty standard.
Product/System Design Round (45 min + 15 min of buffer):
Since in the beginning, I asked the recuiter to put me forward for the product design. Hence this round was focused on understanding my ability to build products from scratch with little to no help.
Question was not difficult, but I had not seen this question before in any of the product/system design interviews not even in G r o k k i n g the design interview. So I followed the basic framework to build any system.
- Functional Requirements (Understanding about the users, system, constraints, security, data privacy etc) (5 - 7 min)
- Non-Functional Requirements (2 - 3)
- Estimations (2 - 3mins)
- Data model (LLD) (5 -7 mins)
- Choice of Database (2 - 3 mins)
- Public APIs exposed (2 - 3 Mins)
- HLD (10 -12 mins)
- Detailed Component discussion on 1 - 2 components where interviewer was interested (5 - 7 mins)
- Improvments in the existing system (5 - 7mins)
Drive the product/system design interivew and stop only when interviewer wants to understand any specifics of the system.
Overall, it was a great interview experience. I am yet to hear from the recruiter.
Best of luck everyone with your upcoming interviews :)
update 1:
@bazzinga2700's question - What's the difference between a product design and a system design interview at Facebook?
Product design is more focused on your understanding of users, optimising the user experience, truly understanding data privacy, geography, age group of consumers etc while system design is focused more on providing the infra. to product engineers where they don't have to worry about the availability, fault tolerance, scalability, performance of their products.