Java Developer

Role: Java Developer ( Performance Tools)

Location: Seattle, WA

Duration: 6 months

Required Skills:

• 6+ years experience required
• Digital : Amazon Web Service(AWS) Cloud Computing
• Advanced Java Concepts
• Microsoft SQL Server 2019
• Java Performance Tools (Jprobe, Jensor, OptimizeIT)

Must Have Technical/Functional Skills:

• JDK Migration & Compatibility Management
• JVM Memory Management & Heap Right-Sizing
• Garbage Collection Tuning (ZGC/G1GC/Shenandoah)
• Java & JVM Internals
• Performance Monitoring & Troubleshooting

Roles & Responsibilities:

• Plan and execute JDK version migrations (JDK 17 to 21, JDK 21 to 25) across service fleets: identifying and resolving blockers including deprecated/removed APIs, module system incompatibilities, reflection access restrictions, security provider changes, and build system (bootstrap/toolchain) compatibility issues.
• Perform heap right-sizing analysis for Java services: profiling heap utilization patterns, analyzing GC logs, identifying over-provisioned heap allocations, and implementing optimal Xms/Xmx/metaspace configurations that minimize DRAM consumption while preserving service performance SLAs.
• Evaluate and implement new GC algorithms and JVM features introduced in target JDK versions (e.g., ZGC generational mode, Shenandoah improvements, compact object headers) to achieve memory efficiency gains beyond simple heap tuning.
• Perform custom operations and iterative experiments using Amazon internal tooling to validate optimization impact: own end-to-end deployment, test execution, metric validation, and derive actionable insights from results.
• Troubleshoot JDK migration issues including class loading changes, serialization incompatibilities, JNI/native library compatibility, and performance regressions introduced by JVM behavioral differences across versions.
• Collaborate with service teams to review service architectures, discuss findings, propose migration plans, and align resolution strategies while communicating effectively across engineering leadership and technical stakeholders.
• Monitor service health metrics and troubleshoot operational issues during and after migration and heap optimization activities, ensuring zero degradation to service latency, throughput, and availability.
• Develop comprehensive operational runbooks, SOPs, documentation, and technical specifications that capture JDK migration patterns and heap optimization strategies, consumable by both human engineers and AI agents to orchestrate workflows at scale.