Senior Java Developer – Freelance (Remote, B2B)

Filled
February 23, 2026
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Job Description

Position: Senior Backend Engineer
Location: Remote (Europe)
Start Date: October 2026
Rate: Up to €45/h (B2B contract)

Overview:
We are seeking a highly experienced Senior Backend Engineer to join our client’s engineering team. This fully remote role focuses on building scalable, secure, and high-performance systems using Java and AWS cloud technologies. You will collaborate with architects, DevOps engineers, and business stakeholders in a cross-functional Agile environment.

Responsibilities:

  • Design, develop, and maintain backend systems using Java, Spring Boot, and AWS.
  • Build RESTful APIs and maintain OpenAPI specifications.
  • Package and deploy applications using Docker and manage AWS deployments.
  • Develop and optimize data models with JPA/Hibernate and PostgreSQL.
  • Work with AWS services: IAM, Lambda, ECS, S3, AuroraDB, Cognito, API Gateway, ECR, CloudWatch.
  • Implement secure authentication/authorization (OAuth2, OpenID Connect, JWT, SAML) and integrate with Azure AD.
  • Collaborate with Salesforce.com teams for API integration and auth flows.
  • Apply Domain-Driven Design (DDD) principles to model complex business domains.
  • Ensure code quality, security, and best practices in cloud architecture.
  • Participate in Agile ceremonies, planning, code reviews, and architecture discussions.

Requirements:

  • Proven experience as a Senior Java Backend Engineer.
  • Strong knowledge of Spring Boot, AWS services, REST APIs, and microservices architecture.
  • Experience with Docker, PostgreSQL, and JPA/Hibernate.
  • Familiarity with authentication/authorization protocols (OAuth2, JWT, SAML).
  • Solid understanding of cloud architecture, security, and best practices.
  • Excellent communication skills in English; able to work independently in a remote setup.

Why Join:

  • Fully remote, flexible work environment.
  • Work on high-impact backend systems for international clients.
  • Competitive hourly rate with B2B contract.