Canva Backend Engineer Interview

The first round of the Canva Backend Engineering interview process is the Recruiter Phone Screen. It’s a pretty straightforward 30-minute conversation with a Canva recruiter, mostly focused on your background and experience. After some quick introductions, they’ll ask about your past work, what attracted you to Canva, and what you’re looking for in your next role. Expect a few behavioural questions as well—nothing too intense, just trying to get a sense of your motivations and fit for the company.

They’ll also take this time to explain the rest of the interview process, walking you through what each stage looks like and what to expect in terms of technical assessments and team interviews.

• Tell me about yourself and your background.
• Why do you want to work at Canva?
• What attracted you to the Backend Engineer role specifically?
• What are you looking for in your next position?
• Can you walk me through one of your past projects?
• How do you approach collaboration with other teams (e.g., product, frontend, etc.)?
• What’s your experience with backend technologies (Java, AWS, microservices)?
• How do you handle tight deadlines or high-pressure situations?

The second round of the interview process is the HR Video Screening, which lasts about 30 minutes. This round is more of a mix between technical and background-related questions. They’ll dive into some Java fundamentals, so be prepared to talk about core concepts like object-oriented programming, data structures, and concurrency. It’s not super in-depth, but they want to ensure you have a solid grasp of the basics.

Alongside the technical questions, they’ll also dig into your past experience—what you’ve worked on, the roles you’ve held, and how your background aligns with the responsibilities at Canva. It’s still a high-level conversation, but you should be ready to explain your key projects and contributions.

• What is the difference between an interface and an abstract class?
• How does garbage collection work in Java?
• Can you explain the concept of multithreading and how Java handles concurrency?
• What is the difference between HashMap and ConcurrentHashMap?
• What’s been your most challenging technical project, and how did you handle it?
• What are some common design patterns you’ve used in Java development?
• Can you walk me through your previous experience and key projects?
• Why are you interested in joining Canva?
• How do you approach solving performance or scalability issues?
• Why do you think Canva is the right fit for your skill set?

The third round of the interview is the *CS Fundamentals round. It’s a 60-minute session that focuses on data structures and algorithms—similar to what you’d find on LeetCode. You’ll be solving coding challenges that test your understanding of algorithms, time and space complexity, and various data structures like arrays, trees, and graphs.

Since Canva’s backend is built primarily on AWS and Java, you should also be prepared for technical questions that dive into distributed systems, microservices architecture, and cloud service optimization. They may touch on concepts like load balancing, scaling, and data consistency across services. It’s a pretty technical round, so make sure you’ve brushed up on both your coding skills and your knowledge of backend systems architecture.

It's best to practise these rounds with a Canva Backend Engineer to get an accurate picture of what these interviews are really like. Book a 1:1 mock session with a Canva Backend Engineer directly here.

• Find the longest substring without repeating characters.
• Rotate an array by k elements.
• Detect a cycle in a linked list.
• Merge two sorted linked lists.
• Implement BFS/DFS on a graph.
• How would you design a highly available URL shortening service like bit.ly?
• How do you handle thread safety in Java?
• Explain the difference between synchronised and Lock.
• How would you scale a Java-based microservices system on AWS?

The Onsite Round for Canva Backend Engineering consists of: 

• 2 Coding interviews 
• 2 System Design Interviews, one with a DS/Algo Focus, and a 
• 1 Behavioural Interview

Coding

The Coding Round of the Canva onsite interview consists of two 60-minute sessions, quite similar to the technical screen. 

Here are 3 tips for this round:

• You’ll want to be solid on core concepts like Graphs, Stacks, Queues, Lists, Sets, Arrays, Hash Maps, and Heaps. Additionally, brush up on Linked Lists, Recursion, and Search and Sort algorithms, as these often come up. Also, expect questions around race conditions, deadlocks, thread synchronisation, or how to implement thread-safe classes. Be ready to talk about Java's concurrency tools like synchronised, volatile, Lock, and thread pools.
• Hit up LeetCode or similar platforms to practise medium to hard-level questions, especially focusing on algorithms, data structures, and object-oriented concepts. Make sure to time yourself so you get used to solving problems within the 60-minute window.
• Effective communication is crucial. While it can be tough to code and talk at the same time, it's important to keep the interviewer in the loop about your thought process. Ask clarifying questions, outline your plan before you start coding, and be willing to adjust your approach based on their feedback. You can also practise this round with a Canva Software Engineer on Prepfully to get a real sense of what to expect and how to navigate the challenges.

DS/Algorithms round with a System Design Element

The third round in Canva's Backend Engineer interview process is a Data Structures/Algorithms round with a System Design twist. You’ll typically be given a problem that requires efficient use of data structures and algorithms such as arrays, hashmaps, graphs, dynamic programming, and sorting algorithms. What sets this round apart is the system design element. After you solve the algorithmic problem, the interviewer may ask you to extend your solution to fit into a larger system or apply it within the context of a scalable, real-world application. For example, after solving a problem involving data storage, they might ask how you would handle the solution at scale, dealing with millions of users or requests.

Be prepared to discuss things like:

• Scalability: How does your solution adapt when the data set grows significantly?
• Efficiency: Can you optimize your algorithm to meet performance constraints?
• Reliability: What happens when failures occur? How does your system recover?
• Trade-offs: Be ready to explain the trade-offs between different approaches, especially when considering space vs. time complexity.
• As you might have guessed it, this round can get tricky. Which is why it's best to partner with a Canva Backend Engineer to get some much needed practice. It would help you brace yourself for what you're up against— what is expected of you, what buzzwords you should hit, etc.
  

This brings us to the final round, the Behavioral Interview. Here, you typically talk with a hiring manager or someone from your intended team about your work experience and how it fits with the job. They might ask about your achievements, challenges you've faced, and how you work with others. It's a fairly standard “behavioural” style interview and you should do fine with just a bit of practice

• What is the difference between Inheritance and Composition in OOP? 
• What is the difference between checked and unchecked exceptions in Java?
• What is the difference between synchronised, volatile, and Lock in Java?
• How would you use Java thread pools in a high-load application?
• How would you design a rate-limiting service for an API?
• Design a system to store and retrieve files at a massive scale (e.g., image storage for Canva).
• How would you design a notification service that can send millions of notifications (email, SMS, push)?
• How would you design a system to allow multiple users to collaborate on a document in real-time?
• How would you design a CDN to serve media assets at Canva globally?
• How would you handle sudden spikes in traffic (e.g., Black Friday sale or viral content)?