Preparing for Mobile Interviews at Monzo

Monzo is a bank on your phone, so iOS and Android engineering is a huge part of what we do. We want you to know exactly what to expect if you’re considering joining us. Our interview process is designed to learn about your strengths and you won’t find any brainteasers or knowledge quizzes. Instead, we look for specific skills and abilities that will make you successful in the role. 

We’re always looking for ways to improve our interview stages and offer a better candidate experience, so our process may change over time, but this is how it looks in September 2024.

The first step is to head over to monzo.com/careers. You’ll find the mobile openings in Engineering with a description of the role and our fantastic benefits. Alongside your CV, the application will ask for written answers to a few questions covering: 

If we think you’re a match for the role, one of our recruiters will schedule a call to learn more about you, answer your questions, and guide you through the process. We’ll always share the outcome or next steps so you’re not left hanging.

In the first interview, you’ll spend 45 minutes on a video call with an engineer in the same role. You won’t be asked to write any code, but you should be prepared to discuss technical topics. 

Format

It should feel more like a conversation than a scripted question set, but we’ll usually cover:

We leave a minimum of 5 minutes for you to ask questions in every interview, so it’s worth making a note of anything you’d like to know about Monzo.

Tips

Be prepared to talk in depth about projects you’ve worked on recently. Your interviewer will want to hear about technology choices, trade-offs, and how you worked as part of a team. There are no “correct” answers. We want to learn about your specific experience building iOS or Android apps.

In general, we hire for problem-solving ability over experience. It’s okay if you haven’t shipped apps in a cross-functional environment before, but we do want to hear how you’d approach the kinds of challenges we face at Monzo.

After a successful initial call, you’ll get the choice between a take-home task or a live pair coding interview. You only have to do one of them, so pick the one that works best for you. If you opt for the take-home exercise, we’ll ask you to make some changes in an existing Android or iOS project. It’s important for us to learn how you work in a mobile codebase. The task is strictly timeboxed to four hours, but there’s no deadline for submission so you can break it up to fit your schedule. 

Format

The sample project has a range of issues, including bugs, code quality issues, missing features, and design inconsistencies. We include a brief describing how it should look and behave. This is an opportunity to demonstrate your coding skills, but we’re also looking closely at how you prioritise and your design instincts.

After you’ve submitted the task, we’ll book a 45 minute video call with one or two engineers in the same role to discuss your solution and approach.

Tips

Stick to the timebox. We’d rather see you make reasoned trade-offs than spend an entire weekend perfecting a solution. In the task review call, you should expect to justify key decisions in your solution and describe what you’d have done differently with more time.

As an alternative to the take-home task, we offer a one hour pair coding interview. You’ll be asked to complete some small tasks in an Android or iOS sample project. 

Format

We send you the project ahead of time so you can get it set up in your IDE. During the interview itself, you’re welcome to use whatever setup and tooling you prefer.

Tips

We aren’t testing your memory or speed - this is a pairing exercise. The interviewer will be paying attention to how you communicate and collaborate, as well as your mastery of the platform and tooling. 

If we’re happy with your task or pairing exercise, we’ll book you in for the final interview. This is made up of two parts: behavioural and mobile systems design.

Format

You’ll have a one hour video call with two interviewers, who might be engineers or engineering managers from any part of the business. They’ll ask four questions exploring your approach to topics like communication, learning, working in a team, and delivering projects. Working at Monzo involves incrementally delivering large scale projects at pace so the collaboration and project delivery skills we explore in this stage are just as important as technical excellence.

Tips

Spend some time reflecting on interesting challenges you’ve faced and projects you’ve worked on in the last few years. We want to hear about specific scenarios drawn from your experience, rather than a discussion in general terms. 

Your interviewers at this stage don’t necessarily have mobile development experience, so be prepared to give an appropriate level of context on any technical details.

We’ll present you with a UI design and some initial requirements and ask how you’d approach building a hypothetical feature. The goal is to produce a blueprint for the end-to-end implementation, with enough detail that we could start implementing something together.

Format

You’ll meet two mobile engineers, and at least one of them will have the same iOS or Android specialisation as you. This is a one hour video call with the help of a virtual whiteboard. 

We don’t write code in this session, except perhaps sketching out some data models and interfaces. The problem focuses on reasoning about the kinds of data flows and abstractions you often encounter as a mobile engineer.

Tips

We’d like you to drive us towards a solution, describing trade-offs and reasoning about technical decisions along the way. We’d rather see a fantastic approach to the problem than a textbook architecture. The key to success in this interview is maintaining a shared understanding of the solution with your interviewers and proactively resolving areas of ambiguity. It’s worth getting familiar with Excalidraw, which is the virtual whiteboarding tool we’ll be using.

We’ll review feedback from all of the interviews, and if we think you’d make a great addition to Monzo, we’ll send over an offer. Of course, interviewing works both ways, so we’ll happily set up chats to answer any further questions that might help with your decision. We hope you’ll join us. 🎉

We’re building a bank for and with our users. A product that’s fair, transparent and a pleasure to use. We're hiring for Android Engineers and iOS Engineers to help us on that journey.