Applied Intuition Software Engineer Interview Experience — Phone Screen, Then an Onsite With a Transactional Key-Value Store

Phone screen

Coding round 1

1. Evaluate variable expressions using + and -.

I was asked to evaluate variables from a list of expressions. Each expression assigns a variable an integer value or an expression containing other variables. Only addition and subtraction need to be supported.

Example input:

a = b + c
d = d + 5
c = 5
d = 10

The task is to calculate the values of variables that can be resolved and identify those that cannot.

Onsite:

Coding round 1

1. Implement a Transactional Key-Value Store

Implement an in-memory key-value store supporting these commands:

• SET key value: assign a value to a key. Overwrite its existing value if present.
• GET key: return the key's current value, or NULL if it does not exist.
• BEGIN: start a transaction.
• COMMIT: permanently save the transaction's changes.
• ROLLBACK: discard the transaction's changes and restore the state before BEGIN.

SET x 10
GET x           → 10
BEGIN
SET x 20
SET y 30
GET x           → 20
GET y           → 30
ROLLBACK
GET x           → 10
GET y           → NULL
BEGIN
SET x 50
COMMIT
GET x           → 50

2. Coding round 2

Implement a hash map like unordered_map in C++. Talked about collision handling with chaining. Discussed multithreading, and how this could be converted to a distributed system.

3. System design:

Design a simulation / job scheduling platform based on hardware requirements.

4. Lead chat (mostly behavioural, from school up to the current date)