janestreet | Other | Interview Experience
Interview Date: Not specified
Result: Not specified
Difficulty: Not specified
Interview Process
I interviewed for a Fullstack/Frontend position.
The first interview was a phone interview where I was asked to create a calculator, trying to mimic the functionality and style of a specific website. I found this task straightforward because a friend had previously encountered the exact same question, and I had practiced beforehand. The next day, the recruiter informed me that I performed well and passed this round. To my surprise, there was a second phone interview before the virtual onsite, which focused on backend algorithms, and I unfortunately did not pass this round.
The second phone interview involved the following question:
I was given an object defined as a set of fields, where each field occupies a certain number of bytes. For example, (foo, 3), (bar, 6), (baz, 2) indicates that during initialization, foo occupies index [0, 3], bar occupies [3, 9], and baz occupies [9, 11].
I could call the function getOffset(field) to return the starting offset of the specified field. For instance, getOffset(bar) would return 3. Additionally, I could call insert(field, length, index) to insert a new field at the specified index (note that this index refers to the order of fields, not the offset) and shift the subsequent fields accordingly. For example, insert(qux, 2, 1) would modify the object to become: foo[0, 3], qux[3, 5], bar[5, 11], and so forth.
The question itself was not particularly difficult, and I completed it, but I struggled with some minor details such as variable naming and edge cases. The interviewer was mainly assessing code cleanliness, communication skills, debugging abilities without running the code, and handling of boundary cases.
Unfortunately, I made repeated mistakes on minor issues due to nerves, and the interviewer had to provide me with hints, which I believe contributed to my not passing.
Technical Questions
- Data Structure: Field Management Problem (Data Structure, Boundary Case Handling)
Tips & Insights
My advice is to remain calm, communicate effectively, and slow down your speaking pace. The questions are not difficult at all.