Performance Testing Engineer

Performance Testing Engineer

About the role

Tax season is seasonal in the extreme: a large share of our customers file in the final days, and on Tax Day they arrive at once. The Performance Testing Engineer is how we know, before that day, that the system will hold. You will build and run tests that push our applications, services, databases and network past their limits on purpose, find where they break, and turn what you learn into concrete fixes, capacity numbers and early-warning signals for the teams that run production.

This is not a scripting-only role. The load test team owns a full-scale environment of its own: load generators, application servers, container platforms, databases, load balancers and mock external services. You will administer it, deploy code to it, break it, tune it and rebuild it. You will work daily with developers, IT and QA, and your findings will change how systems are configured and how code ships.

What you will do

• Design tests. Build and maintain load scripts and replay journeys that reproduce real customer behavior, using AI coding assistants as a daily tool to write, refactor and analyze them.
• Run tests. Drive simulated demand from a normal day to several times peak. Isolate a single component or hit the whole stack end to end.
• Find the limit and explain it. Read dashboards, logs and traces across the application, runtime, database, container and network layers to identify the bottleneck and the metric that would have warned us first.
• Recommend and validate fixes. Propose tuning and configuration changes, apply them in the load test environment, and re-test to prove the effect. Partner with developers when the fix is in code.
• Own the environment. Deploy application and service builds, maintain the load generator fleet, stand up mocks for external dependencies, keep monitoring and alerting healthy, and automate the repetitive parts.
• Report clearly. Document each test run, its configuration and its outcome so results are reproducible and comparable across the season. Give leadership capacity and readiness numbers they can act on.

What we are looking for

• Experience testing or operating server-side web applications, including reading runtime behavior under load (garbage collection, thread pools, connection pools).
• Experience with Linux administration and with containers and orchestration such as Kubernetes.
• Working knowledge of monitoring and observability tools such as Prometheus, Grafana, Elastic and Kibana, and the ability to build dashboards and alerts.
• Strong scripting in at least one language and comfort with Git.
• Daily use of AI coding assistants such as Claude Code or Codex to write, debug and analyze code.
• Experience with automation testing and with browser developer tools for inspecting HTTP traffic.
• Systematic troubleshooting: you form a hypothesis, isolate variables, and let the data decide.
• A real interest in performance: how systems behave at their limits and why.

Nice to have

• Load testing tools such as JMeter, Gatling, k6 or Locust.
• Relational database administration or tuning, including replicated or clustered deployments.
• Configuration management and infrastructure automation tools.
• Cloud infrastructure experience, including running or costing test environments there.
• Network diagnostics with Wireshark, Fiddler or similar, and familiarity with load balancers.
• Software development experience in a compiled backend language.
• Data analysis in SQL against large datasets.