Performance Test Engineer - Python, Locust, automation

  • PCR Digital
  • 16/10/2025
Contractor Information Technology Telecommunications

Job Description

Performance Test Engineer (Python Automation for large-scale, low-latency, distributed systems
Remote Europe)

Location: Remote (Europe & UK only)
Full-Time 6-Month Contract Start Date: within 1-2 weeks
350pd IR35 Outside TBC

We're seeking a hands-on Performance Test Engineer with Strong Python and automation expertise to design, build, and execute the performance testing strategy for a high-scale, ad-serving platform built on Akka-based Java microservices. Required to build automated load frameworks using Locust (Python).

You'll work closely with developers and DevOps engineers to simulate realistic traffic at scale, ensure sub-50ms latency under millions of concurrent users, and drive system optimizations across cloud infrastructure and code. This is a technical, high-impact role ideal for someone passionate about distributed systems performance, automation, and data-driven tuning.

Profile:

  • 3-5+ years of performance engineering for large-scale, low-latency, distributed systems.
  • Proven success meeting p95/p99 latency SLAs under high concurrency (millions of RPS).
  • Strong Python and automation expertise - able to design reusable, scalable test frameworks. Experience with distributed load testing and synthetic traffic modeling in the cloud.
  • Analytical, structured, and effective communicator with strong documentation and collaboration skills.
  • Based in EU or UK with English (C1 or higher).


Nice to have: Java, Bash scripting, Terraform.

Key Responsibilities: Define and execute comprehensive performance test plans (load, stress, spike, soak, scalability, failover). Model real-world streaming traffic patterns (burstiness, fan-out, cache behavior, cold-start, geo distribution). Build automated load frameworks using Locust (Python) or JMeter, with data parameterization and correlation. Manage distributed load generation (containers, cloud workers) to simulate millions of concurrent users. Integrate performance metrics from CloudWatch, Prometheus, Grafana, and OpenTelemetry to analyze system bottlenecks. Develop SLA/SLO dashboards and integrate performance gates into CI/CD pipelines. Collaborate with DevOps and developers to tune JVM, Akka, thread pools, GC, caching, autoscaling, and database performance. Document test approaches, scenarios, results, and provide clear, actionable tuning recommendations.

Tech Stack: Load Tools: Locust (Python), JMeter; k6 or Gatling (nice to have). Languages: Python, Bash, Java (Maven/Gradle, JVM tuning basics). Infrastructure: Docker, Kubernetes, Terraform. Observability: CloudWatch, Prometheus, Grafana, OpenTelemetry. Architecture: Akka-based asynchronous Java microservices.

Logistics: Start date: 17 November 2025. Duration: 6 months (extension possible). Employment type: Full-Time (Freelance allowed). Location: Remote (Europe).

If you're passionate about performance engineering and love optimizing systems that operate at global scale, we'd love to hear from you. Apply now and be part of an agile, innovative European tech team.

Everybody is welcome
Diversity and Inclusion Statement. PCR Digital
"At PCR Digital, we are committed to ensuring that diversity, equity and inclusion play a role at all stages of our recruitment - it is important to us that our own company culture and the culture of our network is as varied and supportive as possible. We love people (it's why we do what we do), so, regardless of background, we welcome you to work with us or apply to any of our jobs if you feel that they are right for you."