5 of 5 Contract OpenAPI Jobs in England

Senior Full Stack Engineer

Hiring Organisation
MarkIT Placements
Location
Didcot, Oxfordshire, South East, United Kingdom
Employment Type
Contract
Contract Rate
From £500 to £700 per day
focus) Design and evolve scalable backend services in Python using FastAPI for high-availability, high-throughput workloads. Build well-versioned RESTful APIs aligned to OpenAPI/Swagger, with strong conventions for consistency, idempotency, and backward compatibility. Implement authentication and authorization using OAuth2/OIDC, session management, and fine-grained … engineering, with a strong focus on backend development in Python and with event-driven architectures. Proven experience designing and operating production REST APIs with OpenAPI/Swagger. Comfortable working in a React/TypeScript codebase. Deep understanding of relational database design, indexing, performance tuning, and migrations (PostgreSQL). Proficiency ...

Open Banking Solution Architect

Hiring Organisation
Stackstudio Digital Ltd
Location
Milton Keynes, Buckinghamshire, South East, United Kingdom
Employment Type
Contract
Contract Rate
From £550 to £600 per day
Deep understanding of OAuth 2.0, OpenID Connect, mutual TLS, certificates, token management, and consent-driven access control. Experience interpreting and applying standards such as OpenAPI, FAPI, and relevant regulatory technical standards. Architecture, Strategy, and Solution Design Significant experience operating as a Solution Architect in complex financial services environments. Proven ...

Contract) Boomi Integration Engineer

Hiring Organisation
Lynko
Location
Manchester, United Kingdom
Employment Type
Contract
strong Boomi hands-on capability). Strong knowledge of integration patterns: synchronous vs async, pub/sub, idempotency, batching, pagination. API fundamentals: REST, SOAP, OpenAPI basics, webhooks, status codes, versioning. Data formats & transformation: JSON, XML, CSV; mapping and validation; basic XSLT helpful. Operational discipline: logging, monitoring, alerting, incident response. ...

Full Stack Developer (ReactJS & Java)

Hiring Organisation
KBC Technologies UK LTD
Location
Leeds, West Yorkshire, England, United Kingdom
Employment Type
Contractor
Contract Rate
Salary negotiable
ReactJS Designing and developing high-performance backend services with Java & Spring Boot Creating scalable REST APIs and microservices Writing clear and maintainable Swagger/OpenAPI documentation Producing Low-Level Designs (LLD) and shaping technical solutions Reviewing code and promoting engineering best practices Mentoring developers and contributing to a strong … hands-on experience with ReactJS Solid backend expertise in Java, Spring Boot, and Microservices Experience designing and consuming RESTful APIs Comfortable creating Swagger/OpenAPI specs Strong understanding of software design and clean code Experience with testing frameworks and automation Practical exposure to Azure and/or GCP Experience ...

QA Test Engineer

Hiring Organisation
Experis
Location
Northampton, Northamptonshire, United Kingdom
Employment Type
Contract
Contract Rate
£400 - £401/day
decisioning components, and integration workflows. Conduct JSON schema validation, payload structure checks, and API contract verification. Review and validate API documentation using Swagger/OpenAPI specifications. Develop Python scripts for simulation, automation, and data validation. Prepare and maintain test plans, test cases, and use cases. Validate decision strategy outputs … Agile ceremonies and support performance/monitoring activities where required. Core Skills Testing: Manual, REST API, Automation Technologies: JSON, JSON Schema, Swagger/OpenAPI Tools: Python, Karate, Excel, LoadRunner, Insomnia/Bruno CI/CD: GitLab, Jenkins Monitoring: Kibana, AppDynamics Concepts: SDLC, TDD, OAuth, Authentication/Authorization, Tokenization/ ...