Senior Performance Test Engineer — Remote-First Ownership

CSHARK; Wrocław; Hybrid; PLN 180,000 - 240,000; Full time

Benefits offered by this job

Flexible hours

International projects

Charity actions

In-house technology workshops

Remote-first culture

Job summary

CSHARK is seeking a Senior Performance Test Engineer to own performance testing across an international project. You will drive the process from requirements and test-data preparation to execution, analysis and final recommendations, using k6 scripts and modern tooling.

You will craft workload models, test REST APIs, and parameterise tests in Azure DevOps Pipelines, while evaluating results with Prometheus and Grafana. Strong English and cross-functional collaboration are essential.

Qualifications

• Proven experience in end-to-end performance testing.
• Strong knowledge of k6 scripting, checks, metrics, and thresholds.
• Ability to design performance scenarios from business requirements.
• Experience testing REST API flows with authentication and data correlation.
• Familiarity with Azure DevOps Pipelines for running and parameterising tests.
• Practical experience with Prometheus and Grafana for performance analysis.
• Experience in preparing and validating test data for performance testing.
• Ability to translate requirements into meaningful workload models and acceptance criteria.
• Strong analytical and troubleshooting skills to identify bottlenecks.
• Experience with AI tools to support testing while validating outputs.

Responsibilities

• Own performance testing end-to-end from requirements to final reporting.
• Design performance scenarios with transactions per hour, load tiers, and acceptance criteria.
• Select k6 workload models and executors for different scenarios.
• Test REST API flows including authentication and data correlation.
• Prepare/validate test data and CSV feeders.
• Run and parameterise tests in Azure DevOps Pipelines.
• Analyze performance metrics with Prometheus and Grafana.
• Correlate client-side results with infra metrics.
• Identify bottlenecks and root causes of failures.
• Prepare evidence-based recommendations for stakeholders.
• Coordinate testing activities across multiple teams.
• Leverage AI tools to assist script development and analysis.

Skills

Performance testing

k6 scripting

Azure DevOps Pipelines

Prometheus

Grafana

REST APIs testing

Test data preparation

AI tools usage

English language

Git

Tools

esbuild

Git

Job description

CSHARK is seeking a Senior Performance Test Engineer to own performance testing across an international project. You will drive the process from requirements and test-data preparation to execution, analysis and final recommendations, using k6 scripts and modern tooling.

You will craft workload models, test REST APIs, and parameterise tests in Azure DevOps Pipelines, while evaluating results with Prometheus and Grafana. Strong English and cross-functional collaboration are essential.