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Middleware Developer

Location Durham
Contract Type Permanent
Hours Full time

About us

As the UK’s most innovative fintech, we’re taking a mobile-first approach and redefining what a bank should be. Using technology, we’re making things easier, transparent and better value for people and businesses.

Based in Durham, we’re committed to bringing world-class career opportunities and developing a strong tech culture in the North East. Our team currently has 350 brilliant people and is still growing; could you be the next innovator to join us?

We’re looking for mindful, empathetic and self-aware people to join our teams in Durham and London, and help us innovate and disrupt the market with our cutting-edge, digital banking solution.

Here’s some of tech we use...

  • React
  • Swift5
  • Kotlin
  • Python
  • GoLang
  • Kafka
  • Google Cloud Platform (GCP)
  • Kubernetes

Our tech journey

We’re investing millions in building the best banking machine in the world on Google’s Cloud Platform. Read more about our move to GCP.

What else should you know…

Platform: We’ve taken the very best cloud native technologies and partnered them with contemporary data architecture to create a platform that we believe is the envy of the world. Read more about our partnership with Thought Machine and our use of hashed ledgers and smart contracts to change banking tech forever.

Agile principles: Our move to GCP means we can fully embrace agile principles with autonomous teams, rapid release cycles and automated testing.

Innovation: Named by KPMG as one of the top ten Global FinTech innovators for four consecutive years, and with multiple projects funded by the UK science budget to bring great analytics and tech to banking, you can expect to be working on cutting-edge projects utilising machine learning and artificial intelligence to transform the way people and businesses do banking.

Role description

You may have heard of us, we are Atom, a completely digital bank with no branches on the high street and no traditional banking website.

We are developing a mobile app that allows you to do your banking wherever you are, whenever you want.

As part of our technology we are developing a middleware layer which services our mobile app and will extend to be the foundation for our bank. We have an opportunity for a permanent developer to join our growing middleware team, were you will work alongside the Architecture, App Dev and Testing teams as well as third parties, playing an important role in building and supporting our middleware.

Key accountabilities/responsibilities

  • You will be responsible for developing various APIs/Services integrating with a number of internal/external backend systems using Mulesoft and appropriate SW languages/tools
  • You will design and develop data models/structures and API contracts, data transforms, algorithms using appropriate SW languages/tools
  • You will be responsible for maintaining all associated design and document artefacts
  • You will ensure that and developed components have the appropriate level of quality and governance (version control, documentation, unit testing
  • You will be responsible for resolving QA defects by working closely with the App Dev and Test teams
  • You will work closely with third parties to facilitate integration and smoke testing
  • You will play an active role in the Middleware support rota and ensure appropriate handling and resolution of any live defects
  • You will take part in daily stand-ups to report your progress, current focus, and any blockers


  • A Bachelor’s degree in computer science or a related field with a minimum of 3 years relevant experience, OR relevance vocational qualification(s) with a minimum of 3 years relevant experience

Key performance indicators

  • Accurate development estimates
  • Quality and ideally defect-free development output
  • Production of accurate documentation and design artefacts
  • Effective triage and resolution of QA defects and Production issues
  • Effective collaboration with all internal and external teams
  • Contribution to technical standards and design decisions
  • Effective time management, good resilience and drive

Essential capabilities/experience

  • 3 years C-like language development experience in an Agile development environment
  • Hands-on ESB/Integration development experience using Mulesoft or similar platform, RESTful APIs with consideration of Unit Testing and Security principles
  • Hands-on integration experience using SOAP/REST/XML/related technologies
  • Experience of securing APIs and developing to secured endpoints using a variety of methods including but not limited to credentials, certificates, tokens
  • Experience of working closely with third parties and external systems
  • Clear communicator both written and verbally

Desired capabilities/experience

  • Mule certification
  • Middleware/ESB/Integration best practice
  • TDD/BDD experience
  • Technical Solution Design, and Technical Documentation experience
  • Improvisation and thinking outside the box to solve complex technical challenges
  • Working in a complex multi-vendor solution environment
  • Financial Services or regulated industry experience
  • Experience of functioning in the capacity of 3rd line support
  • REST API modelling language experience (RAML, JAML, other)
  • Experience in ESB service integration
  • JAVA/C# .NET programming language experience

How do I apply?

Email your application to

with the job title you’re applying for in the subject heading and attach your CV. This is your chance to be you.

The legal bit.

If you send us your CV we'll use your details when we’re looking at your application for this job. We'll also store your CV for six months in case any roles that we think you'd be a great fit for become available.

If you don’t want us to use your details for this, or if you'd like any information at all about how we use your data, then just let us know at