Staff Backend Engineer

About the role

Monzo is looking for a Staff Backend Engineer to help build and evolve its in‑house banking platform. You will join a product squad in Barcelona, collaborating with product managers, designers, data analysts and other engineers to deliver high‑impact features for millions of customers.

Key responsibilities

• Design, develop and maintain backend services that power Monzo’s core banking products.
• Collaborate with cross‑functional squads to define requirements, test hypotheses and ship reliable features.
• Contribute to the architecture and scalability of services using Go, Kafka, Cassandra and other modern technologies.
• Participate in code reviews, mentoring, and the continuous improvement of engineering practices.
• Help ensure security, performance and observability of production systems.

Required profile

• Proven experience building large‑scale backend systems in a fast‑moving environment.
• Strong problem‑solving skills and ability to work across disciplines.
• Comfortable with agile product development and delivering end‑to‑end solutions.

Required skills

• Go
• Cassandra
• Kafka
• Envoy Proxy
• Kubernetes
• Docker
• AWS
• React (for internal dashboards)

What we offer

• Competitive base salary plus benefits.
• Hybrid work model – three days a week in the Barcelona office.
• Opportunity to work on a mission‑driven product with a large engineering team.