(Senior) Java Developer - Freelance

<p>We are looking for a highly experienced <strong>Senior Backend Engineer</strong> to join our <strong>client’s engineering team</strong>. The role focuses on building scalable, secure, and high-performance systems using Java and AWS cloud technologies. You will work in a cross-functional Agile environment, closely collaborating with architects, DevOps engineers, and business stakeholders.</p><p><strong>This is a fully remote position.<br/><br/>Planned start: October<br/>Salary ranges: up to 45EUR/h<br/>Contract: B2B<br/><br/><br/>Responsibilities</strong></p><ul> <li>Design, develop, and maintain backend systems using Java, Spring Boot, and AWS</li> <li>Build RESTful APIs, define and maintain OpenAPI specifications</li> <li>Package and deploy applications using Docker, manage deployments in AWS</li> <li>Develop and optimize data models using JPA/Hibernate and PostgreSQL</li> <li>Work with AWS services including IAM, Lambda, ECS, S3, AuroraDB, Cognito, API Gateway, ECR, CloudWatch</li> <li>Implement secure authentication/authorization using protocols such as OAuth2, OpenID Connect, JWT, SAML, and integrate with Azure AD</li> <li>Collaborate with Salesforce.com teams for API integration and auth flows</li> <li>Apply Domain-Driven Design (DDD) principles to model complex business domains</li> <li>Ensure best practices in code quality, security, and cloud architecture</li> <li>Contribute to Agile ceremonies, planning, code reviews, and architecture discussions</li> </ul><p><strong>Requirements</strong></p><ul> <li><strong>Technical Experience</strong></li> <ul> <li>8+ years of hands-on experience with Java, JUnit, Spring Boot, JPA/Hibernate, SQL, PostgreSQL, REST, OpenAPI</li> <li>8+ years of experience working with Amazon Web Services, especially IAM, VPC, Cognito, API Gateway, Lambda, ECS, S3, ECR, AuroraDB, CloudWatch, AWS CLI</li> <li>Strong experience with containerization and deploying applications using Docker in AWS environments</li> <li>Good knowledge of Domain-Driven Design (DDD)</li> <li>Experience with authentication and authorization standards (AD, Azure AD, SAML, JWT, OAuth2, OpenID Connect)</li> <li>Experience with Salesforce.com (authentication, APIs, authorization)</li> <li>Familiarity with LLMs, AI agents, and Model Context Protocol (MCP)</li> <li>Solid understanding of data structures and application security principles</li> <li>Experience with GitHub, GitHub Actions, JFrog Artifactory</li> <li>Experience in Agile environments, ideally Scrum or SAFe</li> </ul> <li><strong>Certifications</strong></li> <ul> <li>AWS Cloud Practitioner certification required</li> <li>AWS Solutions Architect certification preferred</li> </ul> <li><strong>Soft Skills</strong></li> <ul> <li>Strong communication skills and a proactive, team-oriented mindset</li> <li>Fluent English (spoken and written); additional language skills are a plus</li> </ul> </ul><p><strong>Benefits</strong></p><h3><strong>In return, we offer:</strong></h3><ul> <li>100% remote, flexible work;</li> <li>work with an experienced team of developers and continuous development of your hard and soft skills;</li> <li>dev-friendly processes such as Continuous Integration, Continuous Delivery, Code Review and bug bashes;</li> <li>long-term collaboration on challenging products (FinTech, B2B software, E-commerce and more).</li> </ul><strong>What will happen next?</strong><ul> <li>We would like to know you better, so we will invite you for a meeting with our recruiter.</li> <li>Next, you'll be asked to solve the task or invited to an interview and pair programming with one of our iOS Developers.</li> </ul><p><br/></p><p>Looking for a full-time job? Check out our <a href="https://www.netguru.com/career" rel="nofollow noreferrer noopener">Career Page</a> and find out more about our open recruitment processes.</p><p>If you need any disability-related adaptation at any step of the recruitment process – simply let the recruiter know! We'd be happy to help.</p>