Senior QA Tester

QA Tester- Senior (Hybrid)Location - Denver, CODuration - 4 monthsInterview Type - Virtual / In-PersonNote - Local to Denver; local travel only/none beyond local area. The qualifying questions also indicate the candidate must have the required skills and be okay going into the office.Description - Design and execute test plans for RESTful APIs, Kafka message processors, and Redis-based job schedulers. Build and maintain automated test suites (unit, integration, functional, end-to-end). Design and execute performance and load tests to validate system behavior under peak traffic, sustained load, and stress conditions. Establish performance baselines, define SLAs (throughput, latency, error rates), and track regressions across releases. Conduct soak tests to identify memory leaks, connection pool exhaustion, and resource degradation over time. Validate Node.js library upgrades and dependency changes across the shared library ecosystem (lantern-utils, lantern-nest-utils, lantern-logger, lantern-requester, lantern-scheduler). Test containerized services in Docker and Kubernetes (EKS) environments. Validate CI/CD pipelines (GitLab CI) — ensure builds, tests, and deployments function correctly. Perform regression testing for Node.js runtime upgrades (e.g., Node 18? Node 24 migrations). Collaborate with developers to define acceptance criteria and testability requirements. Monitor and validate application performance using Datadog APM (dd-trace). Test Redis cluster interactions, DynamoDB operations, and Kafka consumer/producer flows. Identify, document, and track defects through resolution.DeliverablesProcess FlowsMentor and Knowledge transfer to client project team membersParticipate as primary, co and/or contributing author on any and all project deliverables associated with their assigned areas of responsibilityParticipate in data conversion and data maintenanceProvide best practice and industry specific solutionsAdvise on and provide alternative (out of the box) solutionsProvide thought leadership as well as hands on technical configuration/development as neededParticipate as a team member of the functional teamPerform other duties as assignedTop SkillsQA Tester5–10 years of QA/testing experience in backend or platform engineeringHands-on experience with performance and load testing toolsAbility to analyze performance metrics such as P50/P95/P99 latencies, throughput, error rates, and CPU/memory utilizationStrong experience with API testing toolsExperience testing event-driven architectures and message queuesFamiliarity with Docker, Docker Compose, and Kubernetes-based deploymentsExperience with CI/CD pipelinesComfortable reading and writing TypeScript/JavaScriptExperience with git workflows and branching strategies