Senior Staff Backend Engineer

Senior Staff Backend Engineer

Cardiff, London or Remote (UK)

We're on a mission to make money work for everyone.

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

London / UK Remote | £155,000 - £200,000 + Equity | Benefits | Technology

Senior Staff Engineer: L70 on our Engineering Progression Framework

About our Engineering Teams:

We have around 650 engineers out of roughly 5,500 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.

Senior Staff Engineer Responsibilities:

A Senior Staff Engineer at Monzo is a hands on engineering leadership (IC) position. As a Senior Staff Engineer you'll:

• Partner with Engineering Directors to shape the technical and product direction of a collective, providing leadership across multiple squads (30–70+ engineers) and ensuring alignment with company-wide priorities.
• Be hands on in both coding and architecture, leading from the front.
• Partner closely with Product and Design leadership to define strategy, shape roadmaps, and make high-quality trade-offs that maximise business and customer impact across the collective.
• Mobilise teams across your collective around high-impact problems, creating clarity, alignment and momentum, injecting urgency when needed, or slowing things down to ensure safety and long-term sustainability.
• Lead and influence architectural direction for the most complex systems, ensuring cohesive, scalable designs across multiple teams and aligning local decisions with the broader system strategy.
• Set and uphold a high bar for technical excellence across the collective, 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.

What you'll be using/ What you'll be working on:

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.

We'd love to hear from you if…

• You have a track record of leading complex, high-impact systems and driving technical direction across multiple teams
• You combine strong technical judgment with product and business awareness, making pragmatic trade-offs
• You've worked on scalable backend, distributed or data-intensive systems
• You're comfortable operating in ambiguous problem spaces, helping teams define direction and execute
• You influence and align senior stakeholders across engineering, product and beyond
• You care about outcomes and impact, using data to guide decisions
• You enjoy mentoring and raising the bar for other engineers

How we work

Locations & Flexible Working:

Our main tech hub is in London, but our engineers live everywhere in the UK— from Brighton to the Western Isles.

We value meeting in person but we don't have a mandated requirement on office attendance, even if you're nearby. We believe you'll do your best work if you are where you want to be. If you live outside of London and we ask you to come into the office, Monzo will support you with the costs.

Our offices are naturally social, especially Tuesdays, Wednesdays and Thursdays, which happen to line up with our twice-weekly Monzo lunches & treat Thursdays. Teams also schedule time together often for work and play – in or around the office, or online.

Set up a work schedule that delivers impact and fits your life:

At Monzo, we value connections, flexibility, and wellbeing. We keep our meetings during core hours to stay connected and believe in maintaining work/life balance.

You'll be empowered to manage your work in a way that suits you and your team, giving you the freedom for children drop-offs and pick-ups, walking your dog or adventurous cat, avoiding peak commuting times or gym slots, appointments, or supporting your family in an emergency.

If you prefer to work part-time, we'll make this happen whenever we can - whether this is to help you meet other commitments or strike a great work-life balance.

Work the way that works for you with Monzo!

What's in it for you

Base salary £155,000 - £200,000 + Equity

We'll help you relocate to the UK.

We can sponsor your visa.

This role can be based in our London office, but we're open to distributed working within the UK (with ad hoc meetings in London)

⏰We offer flexible working hours and trust you to work enough hours to do your job well, and at times that suit you and your team.

£1,000 learning budget each year to use on books, training courses and conferences.

We will set you up to work from home; all employees are given Macbooks and for fully remote workers we will provide extra support for your work-from-home setup.

Plus lots more! Read our full list of benefits.

The application journey has 4 key steps

Our interview process involves four main stages after an informal recruiter call:

1. Recruiter Call
2. Initial Call
3. System Design Interview
4. Take home task or pair coding exercise
5. Final interview including a behavioural and a leadership interview

This process should take around 3-4 weeks - your schedule is really important to us, so we promise to be as flexible as possible!

One of our staff engineers has written a detailed blog on their experience through this process, for extra details, hints and tips please see here.

Equal opportunities for everyone

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, 2026 Diversity and Inclusion Report and 2025 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