Performance Test Specialist

Peak traffic on Orbit Orchard's high-volume marketplace platform exposed a bottleneck last quarter that no test caught until customers started noticing slow checkouts, and this freelance role exists specifically to find the next one before that happens again.

You design and run load and stress tests using k6, scripting realistic traffic patterns in JavaScript that mirror how the marketplace actually gets used during peak periods rather than an idealized average day. Once a test run completes, you dig into the resulting metrics to identify which specific service or query is the limiting factor, rather than reporting a vague slowdown and moving on. You also work with engineering teams to validate that a proposed fix actually improves the numbers before it ships to production.

Required: hands-on k6 experience, comfort scripting in JavaScript, and the analytical patience to trace a performance regression back to its root cause rather than its first symptom. This is a mid-level engagement, roughly three to five years of performance testing or backend engineering experience. Deep infrastructure provisioning experience is not required — a separate platform team already handles that layer.

The engagement runs onsite from the Prague office, tied to specific testing campaigns around major releases. You report to the quality engineering manager for the length of each campaign. Every finding ships with a reproducible test script, so a fix can be verified against the exact load profile that exposed the problem.