I Cleared the Resume Round, But Got Rejected After This System Design Interview

Company: Broccoli AI

Rounds Covered: 2

Result: Rejected after Round 2

Round 1: Resume Discussion (30 Minutes)

The first round started with a discussion around my resume.

The interviewer asked me to pick one of my projects and explain it in detail. We discussed how I had built it, the technical decisions I made, and the reasoning behind its overall design.

The discussion went beyond just explaining the project's features. I was also asked questions about its implementation and why I had chosen a particular approach.

One thing I'd suggest is to be thoroughly prepared with every project you mention on your resume. You should be comfortable explaining the architecture, implementation details, challenges, and technical decisions.

Round 2: System Design (60 Minutes)

Problem: Design a Feature Flag System

The requirement was to design a system that allows engineering teams to enable or disable features in a live production environment without having to deploy new code.

The interviewer expected the design to cover two major components:

1. Control Plane

This component would allow engineering teams to manage feature flags.

Some of its responsibilities included:

• Creating and managing feature flags.

• Configuring rollout rules.

• Enabling or disabling features.

• Controlling which users or groups get access to a particular feature.

2. Data Plane

This component would handle feature flag evaluations within running applications.

For example, an application should be able to make a simple call like:

flags.isEnabled("checkout_v2", userId)

Based on the configured rules, the system would return whether the particular feature should be enabled for that user.

I worked through the system design and presented my proposed architecture during the discussion.

However, I felt that the interviewer wasn't very engaged throughout the conversation. That was just my personal impression, and I can't say whether it had anything to do with the final decision.

Unfortunately, I was rejected after the second round.