Booking.Com Software Engineer Interview Questions + Guide in 2025

Booking.com is a leading online travel agency known for its innovative approach to travel bookings and accommodations.

As a Software Engineer at Booking.com, you will be responsible for designing, developing, and maintaining robust software systems that power the platform's core functionalities. This role requires proficiency in various programming languages, with an emphasis on coding best practices and system design principles. You will collaborate with cross-functional teams to implement new features and optimize existing systems while ensuring high performance and scalability.

Key responsibilities include conducting code reviews, participating in architectural discussions, and providing technical guidance to junior engineers. A strong understanding of algorithms, data structures, and software development methodologies is essential. Familiarity with API design and web technologies is important, as you will often work on integrating different components of the booking system.

Traits that make for a great fit include problem-solving skills, attention to detail, and the ability to communicate complex technical concepts clearly. Due to the collaborative environment at Booking.com, being a team player with a positive attitude towards feedback and continuous learning will resonate well with the company's culture.

This guide is designed to help you prepare effectively for your interview at Booking.com by providing insights into the role and expectations, enabling you to showcase your skills confidently.

The interview process for a Software Engineer at Booking.com is structured and consists of several key stages designed to assess both technical skills and cultural fit.

1. Online Assessment

The first step typically involves an online coding assessment conducted through HackerRank. Candidates are given a set of algorithmic problems to solve within a specified time frame, usually around 75 to 90 minutes. The questions often range from easy to medium difficulty and may include topics such as data structures, algorithms, and practical coding challenges relevant to the role.

2. HR Screening

Following the online assessment, candidates usually have a phone interview with a recruiter. This conversation focuses on the candidate's background, motivations for applying, and general fit for the company culture. The recruiter may also provide insights into the role and the team dynamics at Booking.com.

3. Technical Interviews

Candidates who pass the HR screening typically move on to one or more technical interviews. These interviews can include live coding sessions where candidates solve problems in real-time, often with two or more engineers present. The technical interviews may cover a variety of topics, including algorithms, data structures, and system design. Candidates are expected to articulate their thought process and approach to problem-solving during these sessions.

4. System Design Interview

In addition to coding interviews, candidates will likely participate in a system design interview. This stage assesses the candidate's ability to design scalable and efficient systems. Interviewers may ask candidates to design specific components of Booking.com's infrastructure, requiring a deep understanding of system architecture, trade-offs, and best practices.

5. Cultural Fit Interview

The final stage of the interview process often includes a cultural fit interview, where candidates meet with a manager or senior team member. This interview focuses on the candidate's values, work style, and how they align with Booking.com's culture. Questions may revolve around past experiences, teamwork, and how the candidate handles feedback and challenges.

Throughout the process, candidates are encouraged to ask questions and engage with their interviewers to better understand the company and the role.

As you prepare for your interview, it's essential to familiarize yourself with the types of questions that may arise during each stage.

Here are some tips to help you excel in your interview.

Understand the Interview Structure

The interview process at Booking.com typically consists of several stages: an online coding assessment, a recruiter call, a technical coding interview, a system design interview, and a cultural fit interview. Familiarize yourself with this structure and prepare accordingly. Knowing what to expect at each stage will help you manage your time and energy effectively.

Prepare for Coding Challenges

The coding assessments often include algorithmic questions similar to those found on platforms like HackerRank or LeetCode. Focus on practicing problems that involve data structures, algorithms, and real-world scenarios relevant to Booking.com, such as currency conversion or booking systems. Make sure to time yourself during practice to simulate the pressure of the actual interview.

Master System Design Concepts

In the system design interview, you may be asked to design components of Booking.com’s systems, such as payment gateways or booking management systems. Brush up on your knowledge of functional and non-functional requirements, trade-offs, and scalability. Be prepared to discuss your design choices in detail, as interviewers expect a thorough understanding of the systems you propose.

Communicate Clearly and Effectively

Communication is key throughout the interview process. During coding and system design interviews, articulate your thought process clearly. If you encounter a problem, explain how you would approach it rather than just jumping into coding. This will demonstrate your problem-solving skills and ability to collaborate with others, which is highly valued at Booking.com.

Engage with Interviewers

While some candidates have reported a lack of engagement from interviewers, it’s important to actively engage with them. Ask clarifying questions if you don’t understand something, and don’t hesitate to share your reasoning as you work through problems. This can help create a more collaborative atmosphere and may lead to a more positive experience.

Prepare for Cultural Fit Questions

The cultural fit interview is an opportunity for you to showcase your alignment with Booking.com’s values. Be ready to discuss your past experiences, how you handle feedback, and your motivations for wanting to work at Booking.com. Research the company’s culture and values to tailor your responses accordingly.

Follow Up Professionally

After your interviews, consider sending a thank-you email to your interviewers or the recruiter. This not only shows your appreciation for their time but also reinforces your interest in the position. If you don’t hear back within the expected timeframe, it’s acceptable to follow up politely for feedback or updates on your application status.

Stay Positive and Resilient

The interview process can be lengthy and sometimes frustrating, especially if you experience delays or lack of communication. Maintain a positive attitude and be resilient. Use any feedback you receive to improve your skills for future opportunities, whether at Booking.com or elsewhere.

By following these tips and preparing thoroughly, you can enhance your chances of success in the interview process at Booking.com. Good luck!

Coding and Algorithms

1. Describe your approach to solving a problem where you need to merge overlapping intervals.

This question assesses your understanding of algorithms and data structures, particularly how you handle collections of data.

How to Answer

Explain your thought process clearly, including how you would iterate through the intervals and merge them as needed. Discuss the time complexity of your solution.

Example

“I would start by sorting the intervals based on their start times. Then, I would iterate through the sorted list, comparing each interval with the last merged interval. If they overlap, I would merge them by updating the end time of the last merged interval. This approach runs in O(n log n) due to the sorting step.”

2. How would you implement a function to convert an integer to its English words representation?

This question tests your ability to handle string manipulation and recursion.

How to Answer

Outline your plan to break down the problem into manageable parts, such as handling different ranges of numbers separately.

Example

“I would create a helper function to handle numbers less than 1000, breaking the number down into hundreds, tens, and units. For example, for 1234, I would convert it to ‘one thousand two hundred thirty-four’ by recursively calling the function for each segment.”

3. Can you explain how you would design a function to find the shortest path in a graph?

This question evaluates your knowledge of graph algorithms, particularly Dijkstra's or BFS.

How to Answer

Discuss the algorithm you would use, the data structures involved, and how you would handle edge cases.

Example

“I would use Dijkstra’s algorithm for this problem. I would maintain a priority queue to explore the shortest paths from the source node, updating the distances to each node as I find shorter paths. This ensures that I efficiently find the shortest path in O(E + V log V) time.”

4. Describe a coding challenge you faced and how you overcame it.

This question allows you to demonstrate your problem-solving skills and resilience.

How to Answer

Choose a specific example, explain the challenge, and detail the steps you took to resolve it.

Example

“I once faced a challenge where I had to optimize a function that processed large datasets. I analyzed the time complexity and identified bottlenecks. By implementing caching and reducing the number of iterations, I improved the performance significantly.”

5. How would you implement a priority queue?

This question tests your understanding of data structures and their applications.

How to Answer

Discuss the underlying data structure you would use and how you would implement the necessary operations.

Example

“I would implement a priority queue using a binary heap. The insert operation would take O(log n) time, and I would ensure that the highest priority element is always at the root. This allows for efficient retrieval and removal of the highest priority element.”

System Design

1. How would you design a booking system for a travel website?

This question assesses your ability to think through system architecture and design.

How to Answer

Outline the key components of the system, including databases, APIs, and user interfaces. Discuss scalability and data consistency.

Example

“I would start by defining the core components: a user interface for searching and booking, a backend service to handle requests, and a database to store user and booking information. I would use RESTful APIs for communication and ensure that the system can scale horizontally to handle increased traffic.”

2. Describe how you would design a payment processing system.

This question evaluates your understanding of financial transactions and security.

How to Answer

Discuss the flow of transactions, security measures, and how you would handle failures.

Example

“I would design the payment processing system to include a secure API for handling transactions, ensuring that sensitive data is encrypted. I would implement a retry mechanism for failed transactions and log all activities for auditing purposes.”

3. What considerations would you take into account when designing a system for high availability?

This question tests your knowledge of system reliability and fault tolerance.

How to Answer

Discuss redundancy, load balancing, and failover strategies.

Example

“I would ensure high availability by implementing load balancers to distribute traffic across multiple servers. I would also use database replication and failover strategies to ensure that the system remains operational even if one component fails.”

4. How would you approach designing a scalable microservices architecture?

This question assesses your understanding of microservices and their benefits.

How to Answer

Discuss the principles of microservices, including independence, scalability, and communication.

Example

“I would design the architecture to allow each service to be independently deployable and scalable. I would use APIs for communication between services and implement service discovery to manage service instances dynamically.”

5. Can you explain how you would handle data consistency in a distributed system?

This question evaluates your understanding of data management in distributed environments.

How to Answer

Discuss strategies like eventual consistency, CAP theorem, and data partitioning.

Example

“I would implement eventual consistency for non-critical data, allowing for temporary discrepancies. For critical data, I would use distributed transactions and consensus algorithms to ensure data integrity across services.”