Deliveroo Interviews

Sharing my full interview loop for Deliveroo. The process was structured across DSA, system design, and behavioral rounds, with a noticeable emphasis on ownership and open-ended thinking.

Online Assessment (90 mins - Hackerrank)

Section 1:

• 15 multiple choice questions on data structures, algorithms, and system design fundamentals.

Section 2 - Coding Problem:

• Implement a simple Rate Limiter with per-user and per-time constraints.

Section 3 - REST API Problem:

• Build a function to fetch and return the finest hotel based on ratings from a provided API. Required pagination handling and efficient filtering.

Architecture / HLD Round

Topic:

Design a system to handle a flash sale of 6 million burgers in 10 minutes.

Focus Areas:

• Traffic throttling
• Inventory locking
• Order queuing
• Eventual consistency and failure handling
• No over selling

Behavioral Round

Discussion:

Went over five behavioral stories, covering leadership principles like:

• Ownership
• Dealing with failure
• Driving cross-functional decisions

Coding Round

Problem:

Implement a session-based authentication system with support for three types of queries:"generate","renew","count"

It was open-ended, with no fixed solution. Emphasis was on clean API design, data structures, boundary conditions, test cases and performance.

VP / Country Head Round

Discussion Topics:

• Leadership experiences: mentoring juniors, handling disagreement, and complex project delivery
• Strategic thinking around leveraging AI for team productivity
• Vision and product-aligned engineering contributions

I recently went through the interview process for an iOS Engineer role at Deliveroo in India. I decided to share my experience as I found very little information available during my preparation. The process involved several distinct rounds, each testing different aspects of my skills.

Problem Solving Round

This round focused on fundamental data structures. I was presented with a dictionary and an array and asked to filter items from the dictionary based on the array to construct a restaurant menu. It wasn't a complex algorithmic problem, unlike many typical problem-solving rounds I've encountered.

Loop Interviews

After successfully clearing the problem-solving round, I proceeded to a series of "loop interviews."

1. Take-home Task and Code Review

For this segment, I was given a Pull Request (PR) and tasked with reviewing it, providing comments and feedback. Additionally, there was a simple extension task: to create a list of similar movies.

2. Behavioural Round

This round delved into my past experiences and how I handled various professional situations. The questions included:

• "Tell me a time when you faced a lacking colleague? What did you do?"
• "Tell me a time you worked on something complex? How did you do it?"
• "Tell me a time you added something new to your organization? What were the pros and cons?"

I found this round to require a bit of luck, as the interviewer's judgment can significantly influence the outcome, and some aspects are hard to prepare for directly.

3. Architecture Round

The architecture round involved a system design challenge. I was asked to design a delivery architecture specifically for a rider. Screens were provided as context, and I was expected to design the entire end-to-end flow, including UI components, API endpoints and responses, and appropriate design patterns.

4. Extended Take-home Task Discussion

In this final round, I had to explain my initial take-home task. I was asked what I would add or remove from the current project and why. Following that, I was given a block of code from the same project and asked to identify and fix a subtle bug. My specific bug involved multiple search requests being fired simultaneously, leading to data that might not correspond to the latest query; I had to propose a fix for this data inconsistency issue.

Overall, while the behavioral round felt somewhat dependent on the interviewer, the other rounds were a clear test of my knowledge and practical experience.