Senior Java API Developer

job summary:Role SummaryWe are seeking a Senior Java API Developer with robust experience in designing,building, securing, and optimizing RESTful microservices on AWS. This role requiresdeep expertise in Java, REST API design, application security, OAuth2, and AWS cloudservices, along with a solid understanding of design patterns, exception handling, andtesting frameworks. The ideal candidate will be responsible for delivering highlyperformant, secure, and scalable APIs in a cloud-native environment.Note: Hands on experience on AI tools is a plus.Key ResponsibilitiesAPI Design & DevelopmentDesign, develop, and maintain RESTful APIs using Java and industry bestpractices.Define and implement REST API key features, including proper resourcemodeling, HTTP methods, status codes, pagination, filtering, versioning, andidempotency.Apply object-oriented and application design patterns (e.g., Singleton,Factory, Builder, Adapter, Strategy) to ensure maintainable and extensiblecodebases.Develop cloud-native APIs that integrate with AWS services and serverlessComponents.Performance & ScalabilityIdentify and implement REST API performance improvements, including:Efficient request/response payloads and serializationCaching strategiesConnection pooling and resource optimizationAsynchronous and non-blocking processing where applicableMonitor and analyze application performance metrics and resolve bottlenecks.SecurityImplement application security best practices, including authentication,authorization, encryption, and secure configuration management.Design and implement OAuth2-based security using industry-standard flowsand grant types (Authorization Code, Client Credentials, Refresh Token, etc.).Ensure APIs are protected against common vulnerabilities.Exception Handling & ReliabilityDesign and implement robust exception handling strategies for APIs, ensuringconsistent and meaningful error responses.Implement centralized logging, error tracking, and resiliency patterns (retry,fallback, circuit breaker).Testing & QualityWrite comprehensive unit, integration, and API tests using modern testingframeworks.Ensure high code quality through test coverage, code reviews, and adherence tocoding standards.Support CI/CD pipelines with automated test execution.Cloud & Infrastructure (AWS)Design and deploy cloud resources using AWS CloudFormation.Develop and integrate AWS Lambda functions for serverless use cases.Configure and manage AWS IAM roles and policies following the principle ofleast privilege.Collaborate on cloud architecture decisions for scalability, security, and costoptimization.Collaboration & LeadershipWork closely with product owners, Technical Lead, architects, and DevOps teamsto deliver high-quality solutions.Mentor junior developers and provide technical guidance and best practices.Participate in design reviews, sprint planning, and production support activities.Required Skills & QualificationsRobust hands-on experience with Java and RESTful API developmentDeep understanding of REST API design principles and key featuresSolid knowledge of application design patternsProven experience with REST API performance optimizationrobust background in application security and secure coding practicesExperience implementing exception handling and error management strategiesHands-on experience with testing frameworks (unit, integration, API testing)robust knowledge of OAuth2 and various grant typesExperience with AWS CloudFormation, AWS Lambda, and AWS IAMWorking knowledge of Python (scripting, automation, or Lambda development)Experience working in Agile/Scrum environmentslocation: Malvern, Pennsylvaniajob type: Contractsalary: $55 - 60 per hourwork hours: 8am to 5pmeducation: Bachelorsresponsibilities:Key ResponsibilitiesAPI Design & Development Design, develop, and maintain RESTful APIs using Java and industry best practices. Define and implement REST API key features, including proper resource modeling, HTTP methods, status codes, pagination, filtering, versioning, andidempotency. Apply object-oriented and application design patterns (e.g., Singleton, Factory, Builder, Adapter, Strategy) to ensure maintainable and extensiblecodebases. Develop cloud-native APIs that integrate with AWS services and serverless Components.Performance & ScalabilityIdentify and implement REST API performance improvements, including: Security authorization, encryption, and secure configuration management. and grant types (Authorization Code, Client Credentials, Refresh Token, etc.).Efficient request/response payloads and serializationCaching strategiesConnection pooling and resource optimizationAsynchronous and non-blocking processing where applicable Monitor and analyze application performance metrics and resolve bottlenecks. Implement application security best practices, including authentication, Design and implement OAuth2-based security using industry-standard flows Ensure APIs are protected against common vulnerabilities. Exception Handling & Reliability Design and implement robust exception handling strategies for APIs, ensuring consistent and meaningful error responses. Implement centralized logging, error tracking, and resiliency patterns (retry, fallback, circuit breaker).Testing & Quality Write comprehensive unit, integration, and API tests using modern testing frameworks. Ensure high code quality through test coverage, code reviews, and adherence to coding standards. Support CI/CD pipelines with automated test execution. Cloud & Infrastructure (AWS) Design and deploy cloud resources using AWS CloudFormation. Develop and integrate AWS Lambda functions for serverless use cases. Configure and manage AWS IAM roles and policies following the principle of least privilege. Collaborate on cloud architecture decisions for scalability, security, and cost optimization.Collaboration & Leadership Work closely with product owners, Technical Lead, architects, and DevOps teams to deliver high-quality solutions. Mentor junior developers and provide technical guidance and best practices. Participate in design reviews, sprint planning, and production support activities. qualifications:Required Skills & QualificationsRobust hands-on experience with Java and RESTful API developmentDeep understanding of REST API design principles and key featuresSolid knowledge of application design patternsProven experience with REST API performance optimizationrobust background in application security and secure coding practicesExperience implementing exception handling and error management strategiesHands-on experience with testing frameworks (unit, integration, API testing)robust knowledge of OAuth2 and various grant typesExperience with AWS CloudFormation, AWS Lambda, and AWS IAMWorking knowledge of Python (scripting, automation, or Lambda development)Experience working in Agile/Scrum environmentsPreferred QualificationsExperience with microservices and serverless architecturesFamiliarity with API gateways and service-to-service authenticationExperience with monitoring, logging, and observability tools in AWSExposure to CI/CD pipelines and Infrastructure as Code (IaC) best practicesEqual Opportunity Employer: Race, Color, Religion, Sex, Sexual Orientation, Gender Identity, National Origin, Age, Genetic Information, Disability, Protected Veteran Status, or any other legally protected group status.At Randstad Digital, we welcome people of all abilities and want to ensure that our hiring and interview process meets the needs of all applicants. If you require a reasonable accommodation to make your application or interview experience a great one, please contactPay offered to a successful candidate will be based on several factors including the candidate's education, work experience, work location, specific job duties, certifications, etc. In addition, Randstad Digital offers a comprehensive benefits package, including: medical, prescription, dental, vision, AD&D, and life insurance offerings, short-term disability, and a 401K plan (all benefits are based on eligibility).This posting is open for thirty (30) days.Any consideration of a background check would be an individualized assessment based on the applicant or employee's specific record and the duties and requirements of the specific job.