Lead Performance Tester (SDET)

Vonage; Poland; On-site; PLN 180,000 - 280,000; Full time

Job summary

Vonage invites an experienced Performance Engineering Lead to shape and drive the testing strategy for high-availability, cloud-native platforms.

You will mentor a distributed group of SDETs to design, implement, and execute scalable performance scripts across multiple feature teams.

Qualifications

• Demonstrated hands-on backend performance engineering and automation.
• Experience mentoring QA/SDET teams and coordinating cross-team test schedules.
• Strong experience with AWS cloud services and scalability.
• Proficient in performance testing with tools like k6, JMeter, or Gatling.
• Hands-on with production traffic shadowing/replay tools (GoReplay).
• Familiar with distributed systems, event-driven architectures, and high-volume APIs.
• Ability to integrate performance testing into CI/CD pipelines (Jenkins, GitHub Actions).
• Experience with observability tools for performance analysis (Grafana, PMM, CloudWatch).
• Strong understanding of system design, concurrency, throughput, latency, and fault tolerance.

Responsibilities

• Define and lead the performance engineering strategy across cloud platforms.
• Coordinate a distributed guild of SDETs to build and run performance scripts.
• Develop scalable performance frameworks focusing on APIs, databases, and infra.
• Implement production traffic replay strategies and realistic load profiles.
• Own load, stress, endurance, and resilience testing including chaos engineering.
• Validate real-time systems and high-throughput distributed services under prod-like conditions.
• Integrate performance testing into CI/CD and enable automated PR blocking.
• Leverage observability tooling to monitor and troubleshoot performance.
• Establish benchmarks, SLAs, SLOs, and error budgets.

Skills

Leadership & mentoring

AWS cloud services

Performance testing

K6 tooling

GoReplay

CI/CD integration

Observability

Distributed systems

QA/SDET leadership

Tools

k6

GoReplay

JMeter

Gatling

Kafka

RabbitMQ

Grafana

CloudWatch

Coralogix

PMM

Jenkins

GitHub Actions

Job description

Join Vonage and help us innovate cloud communications for businesses worldwide!

What You Will Do

• Define and lead the performance engineering strategy across high-availability, cloud-native telecom platforms.
• Lead, train, and coordinate a distributed guild of SDETs across multiple feature teams, guiding them to build, maintain, and execute performance scripts (k6) within their fractional sprint capacity.
• Design, develop, and evolve scalable backend performance frameworks using k6, Python, Java, or TypeScript, focusing entirely on APIs, databases, and infrastructure.
• Implement and manage production traffic replay strategies (e.g., GoReplay) and complex multi-tenant test data generation to accurately recreate realistic production contention and load profiles.
• Own and drive performance, load, stress, endurance, scalability, and resilience testing, including chaos engineering practices (e.g., using AWS Fault Injection Simulator).
• Validate real-time communication systems, event-driven architectures (Kafka, RabbitMQ), and high-throughput distributed systems under production-like conditions.
• Integrate performance testing into CI/CD pipelines , enabling continuous performance validation, shift-left practices, and automated PR blocking for latency degradation.
• Leverage observability tooling (Grafana, CloudWatch, Coralogix, VictoriaMetrics, PMM) to monitor, analyse, and troubleshoot system performance.
• Establish performance benchmarks , SLAs, SLOs, and error budgets aligned with business and system requirements.
• Collaborate with architecture and data teams to identify bottlenecks, validate database architectures (e.g., MySQL, Tungsten), and present evidence‑based investment proposals.
• Analyse and optimise performance across both legacy monolith systems (requiring integrated load testing) and modern microservices architectures.

What You Will Bring

• Proven experience mentoring and coordinating testing efforts across large, distributed engineering teams (e.g., conducting code reviews, guiding SDETs through framework adoption, and managing cross-team test schedules).
• Strong hands‑on experience with AWS cloud services (EC2, ECS, RDS, API Gateway) with a focus on scalability and performance optimisation.
• Proven expertise in performance testing tools (specifically k6, along with JMeter or Gatling), including test design, execution, and analysis at scale.
• Hands‑on experience with production traffic shadowing or replay tools (such as GoReplay).
• Deep experience testing distributed systems, message brokers (Kafka, RabbitMQ), microservices architectures, and high-volume, low-latency APIs.
• Solid backend programming and scripting skills in Python, Java, or TypeScript to build custom performance frameworks and tooling.
• Strong understanding of system design , concurrency, throughput, latency, and fault tolerance principles.
• Experience implementing performance testing within CI/CD pipelines (Jenkins, GitHub Actions) and enabling continuous performance feedback loops.
• Hands‑on experience with observability and monitoring tools (Grafana, Coralogix, PMM) for performance analysis and diagnostics.
• Experience working within Agile environments and translating performance insights into actionable engineering outcomes.

Required

• Demonstrable hands‑on experience in backend performance engineering and automation using Python, Java, or TypeScript.
• Proven track record of performance, scalability, and resilience testing in AWS-based cloud‑native systems.
• Strong experience designing large‑scale performance test strategies and leading QA/SDET teams to execute them.
• Deep understanding of API performance testing, integration testing, and system‑level non‑functional validation.
• Solid grasp of system architecture, distributed systems behaviour, and non‑functional testing methodologies.
• Experience with observability, monitoring, and log analysis tools.
• Familiarity with RESTful APIs and event‑driven systems.

Application Requirements

• Updated CV clearly demonstrating performance engineering leadership, cross‑team coordination, AWS expertise, and backend automation frameworks.
• Summary of performance testing frameworks, tools (e.g., k6, GoReplay), and CI/CD methodologies implemented.
• Detailed examples of performance testing engagements (scale, environments, bottlenecks identified, business impact, improvements delivered).
• Evidence of driving performance strategy, mentoring QA/SDET teams, and influencing architecture.

There’s no perfect candidate. You don't need all the preferred qualifications to make a valuable impact on our team. Our employees and customers come from diverse backgrounds, so if you're passionate about what you could achieve at Vonage, we'd love to hear from you.

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Who we are:

Vonage is a global cloud communications leader. And your talent will further help brands - such as Airbnb, Viber, WhatsApp, and Snapchat - accelerate their digital transformation through our fully programmable-based unified communications, contact center solutions, and communications APIs. Ready to innovate? Then join us today.

Note: The purpose of this profile is to provide a general summary of essential responsibilities for the position and is not meant as an exhaustive list. Assignments may differ for individuals within the same role based on business conditions, departmental need or geographic location.