Black Rock

Role: Associate (Java Developer)

College: Not Specified

Interview Date: April 2024

Interview Type: Full-Time

Result: Selected (Offer)

Difficulty: Medium

Rounds: 3 rounds

Topics Asked: Coding (simple logic, multithreading), Data Structures (Linked List Cycle, HashMap), OOPs (Singleton pattern, immutable class), Java Concurrency (wait(), notify(), notifyAll(), synchronized keyword, fail-fast/fail-safe iterators), Spring Boot Profiling, REST API (GET vs POST), Techno-managerial, Resume discussion

Experience:

A recruiter from BlackRock reached out for a Java developer position. All rounds were scheduled on the same day.

Round 1: Coding Round

• An easy-level coding question (simple if-else based) was given. The candidate solved it within 5 minutes and explained multiple approaches.
• Discussion on how to load files/indexes during application startup and using multithreading for it.

Round 2: Technical Round

Duration: 1 hour.

• Coding Problem: LeetCode problem "Linked List Cycle" (https://leetcode.com/problems/linked-list-cycle/description/). Coded within 5 minutes and explained multiple approaches.
• Internal HashMap working: Discussion on its implementation.
• Difference between Concurrent HashMap and HashMap.
• Singleton pattern: Asked to write code.
• Profiling in Spring Boot.
• Difference between wait(), notify(), and notifyAll().
• Difference between fail-fast and fail-safe iterators.
• Difference between GET and POST in REST API.
• Synchronized keyword: What it is and its uses, asked to write code with multiple follow-up questions.

Round 3: Techno-Managerial Round

• Questions were asked from the resume.
• Behavioral questions like "Why are you looking for a change?" and "Why BlackRock?".

Result: Received confirmation from the recruiter after 3 days.