JWT/JSON Developer

JWT / JSON Developer

Location: London – Hybrid / 2 days per week onsite

Contract Length: 6 months

Day Rate: Up to £650 a day (Outside IR35)

We’re supporting a leading UK financial services organisation in the search for an experienced JWT / JSON Developer to join a high-performing engineering team on an initial 6-month contract.

This role will focus on authentication, authorisation and secure service-to-service communication across a large-scale digital platform. You’ll be working on OAuth 2.0 and OpenID Connect (OIDC) implementations, JWT-based authentication, and integrations with identity providers within a modern cloud-native environment.

Key Responsibilities

• Develop and maintain authentication and authorisation services
• Implement OAuth 2.0 and OIDC integrations with identity providers
• Work with JSON Web Tokens (JWTs), including issuance, validation, signing and key management
• Contribute to CI/CD pipelines and trunk-based delivery practices
• Write and review technical documentation
• Collaborate with engineering, security and platform teams on solution design and delivery

Essential Experience

• Strong experience working with Identity Providers (IdPs)
• Solid understanding of OAuth 2.0 and OpenID Connect (OIDC)
• Hands-on experience with JSON Web Tokens (JWTs)
• Knowledge of asymmetric cryptography and secure authentication principles
• Experience with Git, CI/CD and modern software delivery practices
• Advocate of TDD and collaborative engineering approaches

Desirable Experience

• Ability to read and understand Java
• Kubernetes experience
• AWS cloud exposure

Reasonable Adjustments:

Respect and equality are core values to us. We are proud of the diverse and inclusive community we have built, and we welcome applications from people of all backgrounds and perspectives. Our success is driven by our people, united by the spirit of partnership to deliver the best resourcing solutions for our clients.

If you need any help or adjustments during the recruitment process for any reason, please let us know when you apply or talk to the recruiters directly so we can support you.