Grubhub Staff Software Engineer - Backend Interview Guide

The Staff Software Engineer - Backend position at Grubhub is a technical role focused on building scalable, high-performance backend systems. The interview process for this role is comprehensive and evaluates a candidate’s technical skills, problem-solving ability, and fit within the team and company culture. Based on interviews from recent candidates, here’s an in-depth look at what to expect when applying for this position.

Interview Process Overview

1. Recruiter Screening:

Initial Call:

The first step is typically a call with a recruiter. During this conversation, the recruiter will discuss your background, the role’s expectations, and your interest in Grubhub. This is often more of a cultural fit check, and the recruiter may ask some technical questions, but it’s mainly to confirm your experience and to assess your general interest in the company.

• Example Question: “Can you walk me through your experience with backend development, particularly around scaling systems?“

2. Technical Screening (Coding Interview):

If you pass the recruiter screening, you’ll likely be invited to a technical screening. This usually involves coding exercises or questions that assess your understanding of data structures, algorithms, and system design. You may be asked to solve problems on a platform like HackerRank or LeetCode.

• Example Coding Question: “Given a large dataset, how would you design a system that can efficiently process and store this data?”
• Example Algorithm Question: “Write a function to find the shortest path between two nodes in a graph using Dijkstra’s algorithm.”

Expect to demonstrate your problem-solving process, explain your approach to optimization, and show how you handle edge cases and write efficient code.

3. System Design Interview:

For the Staff Engineer role, Grubhub places a heavy emphasis on system design. In this round, you’ll be tasked with designing complex backend systems that scale well. You’ll be asked to design systems that handle large volumes of data or user requests while ensuring reliability and performance.

• Example System Design Question: “Design a real-time food delivery tracking system that can handle millions of users and provide real-time updates on their orders.”

Key Concepts:

Prepare to discuss concepts like load balancing, caching, database partitioning, high availability, and fault tolerance. You’ll need to explain the architecture and justify your technology choices.

4. Technical Deep Dive:

This round focuses on a deeper dive into your technical expertise. You may be asked to discuss past projects, particularly those that involved building distributed systems, managing backend APIs, or working with technologies like AWS, Docker, Kubernetes, NoSQL databases (e.g., Cassandra), and CI/CD pipelines.

• Example Question: “Tell us about a time when you designed a highly available system. What challenges did you face, and how did you overcome them?”

Expect questions on how you handle system resource management, how you ensure scalability under heavy load, and how you approach performance tuning in large systems.

5. Behavioral Interview:

The final round typically involves a behavioral interview to assess cultural fit and leadership skills. You may be asked to explain how you work in teams, manage conflicts, and approach decision-making. Since this is a Staff Engineer position, the company wants to assess your leadership potential and how you handle complex situations.

• Example Behavioral Question: “Tell me about a challenging situation where you had to collaborate with a cross-functional team. How did you ensure the success of the project?”
• Example Leadership Question: “Describe a time when you had to take ownership of a project with little guidance. How did you manage the project and ensure its success?“

6. Final Round with Senior Leadership:

In the final round, you might meet with senior leadership or VPs to discuss your alignment with Grubhub’s long-term goals and your potential to drive the company’s technical initiatives. This is also a chance to demonstrate your communication skills, as you will likely present your system design or a project you’ve worked on.

• Example Question: “How do you prioritize engineering tasks when working on high-impact projects? How do you ensure alignment with business goals?”

Key Skills Grubhub Looks For

1. Strong Technical Fundamentals:

A solid understanding of data structures, algorithms, and design patterns is crucial. You’ll need to demonstrate your ability to write efficient and scalable code. Grubhub values candidates who can solve complex problems, optimize systems for performance, and write code that’s maintainable and easy to scale.

2. Distributed Systems and Scalability:

Experience in building distributed systems is key. The company expects you to understand how to manage high availability, fault tolerance, and distributed data storage across services.

• Example: Knowledge of Cassandra, Kafka, AWS, and Docker will help you succeed in these discussions.

3. Backend Technologies:

Expertise in backend technologies is essential. You’ll likely be working with technologies like Java, Python, Node.js, or Go. Grubhub is also looking for experience with containerization (e.g., Docker, Kubernetes) and microservices architectures.

• Example Question: “How would you optimize the performance of a backend API handling thousands of requests per second?“

4. Cloud Infrastructure:

Experience with cloud platforms such as AWS or Google Cloud Platform (GCP) is crucial. You should be familiar with cloud-native architectures and managing backend systems in the cloud.

• Example Question: “Explain how you would design a highly scalable backend system using AWS services like EC2, Lambda, and RDS.”

5. CI/CD and DevOps Practices:

Familiarity with CI/CD pipelines and tools like Jenkins, Spinnaker, or Gradle is important for automating deployments and managing software delivery.

• Example Question: “How would you automate the deployment of a microservice to production? What tools would you use?“

6. Problem-Solving and Ownership:

Grubhub values candidates who can take ownership of projects, prioritize tasks effectively, and solve technical problems independently. As a Staff Engineer, you are expected to work with minimal supervision and make decisions that impact the entire team.

• Example Question: “Tell me about a time you had to make a critical technical decision under pressure. How did you ensure the decision was the right one?”

Example Interview Questions

Technical Questions:

• “Describe how you would optimize a backend service that processes payments for millions of users.”
• “Design a system for a food delivery app that ensures restaurant orders are processed in real-time with minimal latency.”
• “How would you approach debugging a system experiencing high latency under load?”

System Design:

• “Design a URL shortening service like bit.ly. What components would you use, and how would you ensure scalability and fault tolerance?”
• “How would you design a recommendation system that suggests food to diners based on their past orders?”

Behavioral:

• “How do you handle conflicts within a team? Can you give an example from your past work?”
• “Tell us about a time when you had to balance technical debt and new feature development. How did you make the decision?”

Tips for Preparation

1. Review System Design:

Prepare for system design interviews by practicing with real-world problems. Use platforms like Educative, LeetCode, or Grokking the System Design Interview to get familiar with complex architectures.

2. Master the Basics:

Make sure you have a solid grasp of core backend concepts, data structures, and algorithms. Practice coding problems to ensure your solutions are efficient and scalable.

3. Study Distributed Systems:

Since Grubhub operates at a large scale, review how large distributed systems are built, focusing on consistency vs. availability (CAP theorem), sharding, and replication.

4. Prepare Leadership Examples:

Be ready to discuss how you’ve led teams or taken initiative in projects. Grubhub values ownership and leadership in senior technical roles.