INTERIM Java & API Engineer/Architect

• Renommiertes Unternehmen in Düsseldorf
• java, API, Freelance, freelance, Freiberuflich

FIRMENPROFIL:

Start: asap

Project duration: 6 months + extension

Utilisation: 80-100 %

Location: Remote and onsite every 3 months in Düsseldorf or Wuppertal

Industry: Production

Project language: English/German

AUFGABENGEBIET:

We want to extend the current IT Landscape consisting of data producers and automation tools (f.e. SAP Emarsys) and develop a solution how to best integrate the systems with an existing SaaS application Ecosystem to establish a secure, resiliant and robust connection for the systems to interact with each other. The ideal candidate will have excellent all-round skills in the design, development, implementation, and testing of robust APIs, ensuring high standards of quality, security, and maintainability throughout the API lifecycle.Tasks:

• Together with other Architects/Engineers extend and adopt current APIs on the upstream side, Emarsys being the most important one.
• The solution design would need to encompass that the information from the Webhook API of Emarsys will need to be delivered on the existing touchpoints of an ios and android Hybrid App and the Clients device.
• The server side backend of the named touchpoints is deployed in the cloud (Spring Boot App on AWS EKS).
• The service middleware must ensure that the information payload and also the segmented customer data does not break the business continuity of the clients System therefore forsee checking strong sanity and quality of the payload from the Emarsys system to the customer touchpoints.
• The candidate will need to be capable to work together with other developers, architects, security experts, cloud platform engineers to expand on learnings of the prototype and develop a secure production ready solution design that is highly resilient, fault tolerant and maintainable.
• Work together with architects and other specialists on the Architecture Decision Records and document the solution taking Arc42 documentation standard as baseline.
• Report, align and provide status Update with Overall PO, PM and Architect

ANFORDERUNGSPROFIL:

• xcellent programming skills developing software that serves millions of end customers.
• Have to be able to work autonomously and in team with other developers and architects.
• Excellent and demonstratable knowledge of latest Java and Spring Boot versions within containerized environment.
• Hands-on experience with modern API development frameworks and tools (e.g., Swagger/OpenAPI).
• Track record of successful API implementations in complex technical environments.
• Strong proficiency in designing RESTful and/or GraphQL APIs, including schema design, versioning, and documentation best practices.
• Proven ability to architect API solutions that are secure, maintainable, and performant.
• Experience with API security standards and protocols (e.g., OAuth2, JWT, CORS).
• Ability to translate business requirements into well-structured API designs; experience with schema modeling and API documentation.
• Skilled in developing and executing comprehensive test plans for APIs; experience with automated testing frameworks.
• Advanced debugging and troubleshooting skills for API integration and deployment issues.
• Knowledge of mobile application development (iOS/Android) is a plus.
• Experience with development in embedded environments (Yocto Linux, QT Framework) is highly desirable.
• Familiarity with payment gateways and payment processing is a plus.
• Experience with eCommerce systems is also a plus.
VERGÜTUNGSPAKET:


Does the project sound interesting?I look forward to hearing from you with the following information:Your current project availability (earliest start date)

Your maximum workload/week in total
Can you offer this workload on a regular basis?
Your hourly rate (on-site / remote)
Your current profile
A brief feedback on the fit (please address the points listed above)