Mid Backend Engineer

Selina Finance

Backend Engineer developing high-class back-end code for Selina's FinTech product. Working in a microservice architecture to improve customer financial experiences.

Posted 6/10/2026full-timeRemote • 🇬🇧 United KingdomMid-LevelSenior💰 £70,000 - £80,000 per yearWebsite

Tech Stack

Tools & technologies

ApacheDockerGrafanaJavaJUnitKafkaKotlinKubernetesMockitoMongoDBNoSQLPrometheusPythonSpringSpring BootSpringBoot

About the role

Key responsibilities & impact

Help design, shape and deliver a leading FinTech product and engineering team
Contribute to the team’s work with high-quality, well-tested and scalable code
Develop high-class back-end code in a microservice architecture that builds the foundation of all Selina’s tech products
Support the development of the software stack (e.g. code reviews, unit tests, CI) and documentation
Work closely with our team to understand our customers’ needs

Requirements

What you’ll need

Strong knowledge of Java Core, including collections, generics, streams, concurrency basics, and modern Java features.
Good understanding of object-oriented design principles and clean code practices.
Commercial experience with Spring Boot and the Spring ecosystem
Experience building REST APIs, including an understanding of HTTP fundamentals
Experience with service-to-service communication and event-driven architecture, including messaging/streaming with Apache Kafka
Experience with unit and integration testing using tools such as JUnit and Mockito (Testcontainers or WireMock is a plus).
Understanding of web application security basics, including authentication, authorization, and OAuth 2.0 concepts.
Experience working with MongoDB or other NoSQL databases, including basic data modelling and indexing.
Experience with Git and standard collaborative workflows (pull requests, code reviews, resolving conflicts).
Ability to work independently on tasks, collaborate in a team, and deliver features from design to production.
Nice to have/Bonus points
Experience with Kotlin for backend development.
Experience with Keycloak or other Identity and Access Management solutions.
Experience with observability tools such as Grafana, Loki, Prometheus, and logging/monitoring systems.
Experience with Docker and Kubernetes.
Experience with Python and FastAPI for building backend services.

Benefits

Comp & perks

25 days' annual leave, plus bank holidays
30 days’ work-from-anywhere allowance
Bi-annual Bonus (discretionary)
Volunteering allowance
Growth Shares
Annual L&D budget
Cycle to work scheme
3% pension contribution
Monthly socials
Free access to mental health support via ‘Spill’
A choice of benefits that work for you, courtesy of our benefits platform, ‘Thanks Ben’
Annual £60 cycle allowance for Santander cycles or Evans (via ‘Thanks Ben’)
Workplace Nursery Benefit, allowing eligible nursery costs to be paid via salary sacrifice

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Hard Skills & Tools

Java CoreSpring BootREST APIsApache KafkaJUnitMockitoMongoDBGitKotlinDocker

Soft Skills

collaborationindependenceproblem-solvingcommunicationteamwork