Senior Rust / Java Performance Engineer

Job Title: Senior Rust / Java Performance EngineerLocation: Seattle, Washington, 98109 - 100% OnsiteDuration: 6 monthsExperience:6+ YearsCompetencies:Digital : Amazon Web Service(AWS) Cloud ComputingAdvanced Java ConceptsMicrosoft SQL Server 2019Java Performance Tools (Jprobe, Jensor, OptimizeIT)Must Have Technical/Functional Skills:Rust DevelopmentMemory & Performance OptimizationJava/JVM InternalsDistributed Systems & AWSAI Agent-driven Development & TestingRoles & Responsibilities:Drive Java-to-Rust migrations as a DRAM-reduction lever: apply the decision framework to identify genuinely memory/latency-bound services (JVM overhead as a structural ceiling), rank APIs by traffic, and own each migration end-to-end from analysis through cutover.Bring deep system expertise to the agent-driven workflow: define type hierarchies, module boundaries, and API contracts; drive and unblock the Rustify agents rather than merely operating them; and contribute improvements back to the framework when you hit friction.Establish oracle-based correctness and prove functional equivalence: capture production request/response pairs as the source of truth and validate the Rust implementation via progressive zero-diff testing (RustifyComparator) from small samples to full 1000+ scale, distinguishing real bugs from acceptable non-determinism.Implement on the target stack and optimize for memory: build on Smithy Rust Server SDK, ECS Fargate (ARM64/Graviton), CargoBrazil, CDK with @amzn/pipelines, and CloudAuth; then profile hotspots, stress test, and quantify DRAM/latency savings with no functional regression.Execute safe rollout and operations: shadow deploy in Gamma and Prod to prove equivalence on live traffic, drive gradual cutover (canary to 100%) with rollback at each stage, stand up observability (dashboards, alarms, runbooks), and align API compatibility with upstream/downstream teams.Codify reusable learnings: migration guides, runbooks, and friction logs