Sr Java Developer
Job Title: Sr Java DeveloperLocation: Walnut Creek, CA (Hybrid)Duration: Long term contractExperience: 10+ yearsIn-person interview with the clientRate : 55 on C2CClient : SonataAbout the roleWe are hiring a Lead Software Engineer to own technical direction for a large multi-module Java enterprise platform with a modern React UI, batch processing, partner integrations, and AWS-hosted containerized deployments.You will lead design and delivery across a mature codebase while modernizing architecture, cloud operations, and developer experience. Experience building AI agents / LLM-powered workflows is a strong plus.What you'll doLead end-to-end delivery of features across backend services, APIs, UI, and integrationsArchitect and review solutions in a large Maven multi-module Java/Spring applicationGuide evolution of the platform: legacy server-rendered UI alongside modern React, APIs, and batch jobsOwn or partner on AWS deployment and reliability for containerized Tomcat services (ECS, CDK pipelines, secrets, observability)Mentor engineers, set coding standards, drive design reviews, and improve CI/CD and release qualityPartner with product and stakeholders on external integrations.Diagnose production issues across application, database, and infrastructure layers; strengthen monitoring and runbooksOptionally lead or contribute to AI-agent initiatives that automate workflows, data handling, or developer productivityRequired qualifications8+ years professional software engineering experience; 2+ years in a lead / staff / tech-lead capacityDeep expertise in Java (Java 8+; comfort with large enterprise codebases)Strong hands-on experience with Spring (MVC, Security, Batch, SOAP/REST), Hibernate/JPA, and relational data modelingSolid SQL / MySQL skills: schema design, query tuning, transactional integrityExperience with Maven, multi-module builds, and Tomcat (or similar Java app servers)Proven AWS experience in production: ideally ECS/Fargate, ECR, ALB, Secrets Manager / SSM, S3, CloudWatch, and IaC (CDK, CloudFormation, or Terraform)Experience modernizing or maintaining legacy enterprise systems while delivering incremental improvements safelyStrong design, debugging, and communication skills; ability to lead without blocking the teamPreferred qualificationsReact (or similar SPA) experience - Vite, Redux/RTK, Material UI a plusObservability: Datadog, structured logging, APM, on-call practicesDocker, CI/CD (Jenkins, CodePipeline/CodeBuild), artifact registries (CodeArtifact/Nexus)AI agent building experience (plus): Tool-calling agents, MCP, or workflow automation agents applied to enterprise systems