Principal Backend Engineer

We’re waving goodbye to the complicated and confusing ways of traditional banking.

After starting as a prepaid card, our product offering has grown a lot in the last 10 years in the UK. As well as personal and business bank accounts, we offer joint accounts, accounts for 16-17 year olds, a free kids account and credit cards in the UK, with more exciting things to come beyond. Our UK customers can also save, invest and combine their pensions with us. 

With our hot coral cards and get-paid-early feature, combined with financial education on social media and our award winning customer service, we have a long history of creating magical moments for our customers!

We’re not about selling products - we want to solve problems and change lives through Monzo ❤️

We have around 600 engineers out of roughly 5,000 people in total - and we have big ambitions. There are many interesting challenges ahead, and we're happy for people to move between teams or to specialise, whatever you prefer. As an engineer here you'd be able to work directly with anyone across the company, and we run regular knowledge-sharing sessions so you’ll learn heaps about everything from how banks work to effective communication.

We contribute to open source software as much as possible. Our blog is a good place to learn even more about what we do.

A Principal Engineer at Monzo is a hands on engineering leadership (IC) position. As a Principal Engineer you’ll:

• →Partner with and guide Engineering and Product Leaders to shape the technical and product direction of Monzo, providing company-shaping leadership across collectives (100+ engineers) and driving alignment with company-wide priorities, owning problems that materially impact Monzo’s trajectory over the next 1-5 years.
• →Remain hands-on in both coding and architecture where it adds the most leverage, especially in complex, high-risk or novel areas.
• →Actively identifying high-leverage opportunities for Monzo and setting the direction of Engineering effort towards the most impactful outcomes.
• →Mobilise teams across Monzo around high-impact problems, creating clarity, alignment and momentum, injecting urgency, or slowing things down to ensure safety and long-term sustainability.
• →Lead and influence architectural direction for the most complex systems, driving consistency and reuse across domains, aligning local decisions with the broader system strategy.
• →Set and uphold a high bar for technical excellence across Monzo, identifying and driving improvements in quality, reliability and scalability, and fostering a culture where engineers hold each other to that standard.
• →Proactively mentor, sponsor and develop senior engineers and future leaders, multiplying your impact by enabling others to operate at a higher level.

We rely heavily on the following tools and technologies:

• Go to write our application code (there’s an excellent interactive Go tutorial here)
• Cassandra for most persistent data storage
• Kafka for our asynchronous message queue
• Kubernetes and Docker to schedule and run our services 
• AWS for most of our production infrastructure and GCP for most of our data infrastructure.
• React for internal Web dashboards
• Feast for storing our features along a variety of tools to train and deploy models.

• You have a track record of leading complex, high-impact systems and driving technical direction across multiple teams, domains or business areas
• You think in multi-year horizons to look around corners and build for the future, identifying opportunities before they present themselves
• You combine strong technical judgment with product and business awareness, making pragmatic trade-offs
• You’ve worked on large scale backend, distributed or data-intensive systems
• You’re comfortable operating in ambiguous problem spaces, helping teams define direction and execute
• You influence and align the most senior stakeholders across engineering, product and beyond
• You care about outcomes and impact, using data to guide decisions and to iterate
• You enjoy mentoring and raising the bar for other engineers

Diversity and inclusion are a priority for us and we’re making sure we have lots of support for all of our people to grow at Monzo. At Monzo, we’re embracing diversity by fostering an inclusive environment for all people to do the best work of their lives with us. This is integral to our mission of making money work for everyone. You can read more in our blog, 2024 Diversity and Inclusion Report and 2024 Gender Pay Gap Report.

We’re an equal opportunity employer. All applicants will be considered for employment without attention to age, ethnicity, religion, sex, sexual orientation, gender identity, family or parental status, national origin, or veteran, neurodiversity or disability status.

If you have a preferred name, please use it to apply. We don't need full or birth names at application stage 😊