Freelance Backend Engineer

SENIOR BACKEND JAVA ENGINEER (FREELANCE CONTRACT) – HUNGARY

Contract Length: 6+ Months Start Date: ASAP Day Rate: 120,000 HUF – 180,000 HUF per day Location: Hungary

ABOUT THE ROLE

Beyond Sports is looking for an experienced Senior Backend Java Engineer to support a large-scale cloud migration project, moving critical backend services and infrastructure from AWS to Azure.

This is a hands-on freelance contract opportunity for a senior engineer with deep Java expertise, strong cloud migration experience, and a passion for building scalable, high-performance backend systems. You’ll work closely with cross-functional engineering teams to modernise services, improve architecture, and ensure smooth integration across cloud environments.

KEY RESPONSIBILITIES

• Design, refactor, and migrate scalable backend systems and REST APIs using Java and Spring Boot
• Support AWS to Azure migration activities across applications and infrastructure
• Re-architect and modularise services to improve scalability, maintainability, and performance
• Implement secure identity, secrets management, and key vault solutions
• Integrate third-party services including sports data, video, and commentary providers
• Build and maintain APIs supporting web and mobile applications
• Deliver infrastructure changes using Infrastructure as Code tools such as Terraform and Bicep
• Manage deployments and automation through CI/CD pipelines
• Monitor, troubleshoot, and optimise cloud services and application performance
• Collaborate in sprint planning, technical discussions, and code reviews
• Produce clear technical documentation for systems, APIs, and migration processes

REQUIRED SKILLS & EXPERIENCE

Essential

• Strong commercial experience with Java and Spring Boot
• Proven experience delivering AWS → Azure migration projects
• Strong understanding of cloud security, IAM, secrets management, and key vaults
• Experience designing and integrating RESTful APIs
• Docker containerisation experience
• Kubernetes experience across EKS and/or AKS
• Strong knowledge of AWS services including S3, DynamoDB, and RDS
• Experience with Azure services including Cosmos DB, Blob Storage, and Azure Database for MySQL
• Cloud networking knowledge including VPCs, VNets, API Gateway, and API Management
• Infrastructure as Code experience with Terraform
• CI/CD pipeline automation using tools such as GitLab, Bitbucket Pipelines, or ArgoCD

Desirable

• Cloud cost optimisation and performance tuning experience
• Strong testing and QA practices including automation and regression testing
• Kafka or other event-driven architecture experience
• SQL database experience including PostgreSQL, MySQL, or Azure SQL

If you're an experienced backend engineer looking for your next freelance contract within a modern sports technology environment, we’d love to hear from you.