Senior Performance Tester

🏢 Summary: Hybrid Senior Performance Test Engineer role focused on building automated performance testing frameworks and strategies for scalable, resilient digital products. The position uses JavaScript and k6 to test APIs, web applications, and distributed systems, embed testing in CI/CD, and drive performance improvements across engineering teams. 🗂️ Requirements: JavaScript (ES6+) proficiency, Automated test framework development experience, k6 performance testing experience, Load, stress, scalability testing and performance tuning knowledge, REST API and GraphQL API testing experience, CI/CD test integration experience, Git collaborative workflow experience, Docker and Kubernetes experience, Experience with AWS, Azure, or GCP, Observability and monitoring tool experience 📃 Skills: JavaScript, k6, REST, GraphQL, GitHubActions, GitLabCI, AzureDevOps, Jenkins, Git, Docker, Kubernetes, AWS, Azure, GCP, Grafana, Prometheus, ApplicationInsights 🏢 Description: Location: Warsaw, Poland (Hybrid – 2–3 days per week from office) About the Role We are looking for a Senior Performance Test Engineer to join our engineering team and help us build highly scalable, reliable, and resilient digital solutions. In this role, you will design and implement advanced performance testing strategies, develop automation frameworks, and work closely with engineering teams to identify bottlenecks and improve system performance. You will play a key role in embedding performance engineering practices into the software development lifecycle, enabling teams to deliver high-quality products that perform reliably at scale. This is an excellent opportunity for an experienced engineer who enjoys solving complex technical challenges, working with modern cloud technologies, and influencing engineering practices across distributed teams. Key Responsibilities Design, develop, and maintain performance testing frameworks and automation solutions using JavaScript (ES6+) . Create and execute performance, load, stress, and scalability testing strategies for modern applications. Develop and maintain performance test scenarios using k6 . Test and analyze the performance of: REST APIs GraphQL APIs Web applications and distributed systems Identify performance bottlenecks and provide actionable recommendations for optimization. Collaborate with developers, architects, DevOps, and product teams to improve system scalability and reliability. Integrate performance testing into CI/CD pipelines and engineering workflows. Support performance monitoring and analysis using observability platforms. Contribute to performance engineering standards, best practices, and continuous improvement initiatives. Work effectively with global, distributed engineering teams and communicate technical findings to both technical and non-technical stakeholders. Required Skills & Experience Strong proficiency in JavaScript (ES6+) . Proven experience building automated test frameworks and reusable testing solutions. Hands-on experience with k6 performance testing . Strong understanding of performance engineering methodologies, including: Load testing Stress testing Scalability testing Performance analysis and tuning Experience testing modern web applications and APIs, including: REST APIs GraphQL APIs Experience integrating automated tests into CI/CD pipelines , using tools such as: GitHub Actions GitLab CI Azure DevOps Jenkins Strong experience with Git and collaborative software development workflows. Solid understanding of software engineering principles and modern development practices. Excellent analytical and problem-solving skills. Cloud & Infrastructure Experience Experience working with modern cloud and infrastructure technologies: Docker and containerized environments. Kubernetes and cloud-native architectures. At least one major cloud platform: AWS Microsoft Azure Google Cloud Platform (GCP) Experience with observability and monitoring tools, such as: Grafana Prometheus Application Insights Similar monitoring and analytics platforms Soft Skills & Mindset Strong communication and stakeholder management skills. Ability to influence technical decisions and drive improvements without direct authority. Passion for quality engineering, automation, and developer enablement. Continuous learning mindset and curiosity about emerging technologies. Ability to collaborate effectively across international and distributed teams. Comfortable working independently while contributing to a highly collaborative engineering culture.

🏢 Summary: Oferta dla Senior Performance Test Engineera obejmuje rozwój frameworków i automatyzacji testów wydajnościowych aplikacji webowych oraz API. Rola koncentruje się na Performance Testing as Code, integracji z CI/CD, analizie wydajności i współpracy z zespołami deweloperskimi. 🗂️ Requirements: JavaScript (ES6+), Doświadczenie z k6 i automatyzacją testów wydajnościowych, Testowanie aplikacji webowych i REST API, Znajomość narzędzi CI/CD, Doświadczenie z Dockerem i Kubernetes, Doświadczenie z Azure, AWS lub GCP, Analiza wydajności aplikacji i identyfikacja wąskich gardeł, Bardzo dobra znajomość języka angielskiego 📃 Skills: JavaScript, k6, REST, CI/CD, Docker, Kubernetes, Azure, AWS, GCP 🏢 Description: Poszukujemy doświadczonego Senior Performance Test Engineera , który dołączy do zespołu odpowiedzialnego za rozwój nowoczesnych rozwiązań z zakresu testów wydajnościowych i performance engineering. Osoba na tym stanowisku będzie projektować oraz rozwijać frameworki testowe, budować rozwiązania typu Performance Testing as Code oraz wspierać zespoły deweloperskie w dostarczaniu skalowalnych i wysokowydajnych aplikacji. Zakres obowiązków Projektowanie i rozwój frameworków oraz bibliotek do testów wydajnościowych z wykorzystaniem JavaScript (ES6+) i k6 . Tworzenie oraz utrzymywanie automatycznych testów wydajnościowych dla aplikacji webowych i API. Analiza wyników testów, identyfikacja wąskich gardeł oraz rekomendowanie usprawnień wydajności. Integracja testów wydajnościowych z procesami CI/CD oraz rozwój platformy do automatyzacji testów. Współpraca z zespołami deweloperskimi przy definiowaniu najlepszych praktyk w obszarze Performance Engineering. Udział w code review oraz rozwijanie wysokich standardów jakości kodu. Wymagania Bardzo dobra znajomość JavaScript (ES6+) . Praktyczne doświadczenie z k6 oraz automatyzacją testów wydajnościowych. Doświadczenie w testowaniu aplikacji webowych oraz REST API (GraphQL będzie dodatkowym atutem). Znajomość narzędzi CI/CD (GitHub Actions, Azure DevOps, GitLab CI lub Jenkins). Doświadczenie z Dockerem , Kubernetes oraz przynajmniej jedną platformą chmurową ( Azure, AWS lub GCP ). Umiejętność analizy wydajności aplikacji oraz identyfikacji problemów wydajnościowych. Bardzo dobra znajomość języka angielskiego. Mile widziane Doświadczenie w budowie platform do testów wydajnościowych. Znajomość narzędzi observability (Grafana, Prometheus, Application Insights). Doświadczenie w środowiskach regulowanych (np. pharma, healthcare, life sciences). Znajomość praktyk DevSecOps oraz narzędzi wspierających jakość kodu i AI-assisted development.

🏢 Summary: Senior Software Development Engineer in Test role focused on building and maintaining automated UI, API, and end-to-end tests for a DDD-based debt management platform. The role covers testing distributed, asynchronous systems, integrating tests into CI/CD pipelines, monitoring quality metrics, and collaborating in an Agile delivery team. 🗂️ Requirements: 4–5 years of Tester / QA Engineer experience, including 2 years at Senior level, Very good programming skills, TestContainers and API testing tools experience, Functional, regression, integration, and UAT test design experience, Distributed systems and service integration testing experience, Asynchronous, event-driven, queue, messaging, and REST API testing knowledge, UI, API, and end-to-end test automation experience, Domain-Driven Design project experience, C#, .NET 10, xUnit, Reqnroll, Shouldly, Cypress, and Playwright knowledge, GitLab CI/CD and GitHub Actions pipeline and test integration experience, Git branches and merge requests experience, Jira and Xray test management experience, Grafana monitoring knowledge, SQL and PostgreSQL skills, Very good spoken and written English 📃 Skills: C#, .NET, xUnit, Reqnroll, Shouldly, Cypress, Playwright, TestContainers, Swagger, Postman, Apidog, GitLab, GitHub, Git, Jira, Xray, Grafana, SQL, PostgreSQL, REST, DDD, Kanban 🏢 Description: As a recruitment company, DCG understands that every business is powered by experienced professionals. Our management style and partnership approach enable us to meet your needs and provide continuous support. Due to our ongoing growth and the large number of recruitment projects we undertake for our partners, we are currently looking for: Software Development Engineer in Test Responsibilities: Design and create new test scenarios and test cases for functional, regression, integration, and UAT testing Prepare, maintain, and execute automated tests across UI, API, and end-to-end layers Test distributed systems, integrations between services, and REST APIs Validate systems based on asynchronous and event-driven communication patterns Support quality assurance activities within a DDD-based greenfield product Integrate and maintain automated tests within CI/CD pipelines Monitor key system metrics and quality indicators using Grafana Collaborate with Product Owners, business stakeholders, developers, and testers across multiple bounded contexts Participate in Agile delivery processes conducted in a Kanban-like model Contribute to the development of a core debt management platform component Requirements: Minimum 4-5 years of experience as a Tester / QA Engineer, including at least 2 years at Senior level Very good programming skills Hands-on experience with TestContainers and API testing tools such as Swagger, Postman, or Apidog Proven experience in creating test scenarios and test cases for functional, regression, integration, and UAT testing Experience in testing distributed systems and service integrations Practical knowledge of asynchronous and event-driven systems, queues, messaging, and REST API testing Ability to prepare and maintain UI, API, and end-to-end automated tests Experience working in projects following Domain-Driven Design (DDD) principles Strong knowledge of C#, .NET 10, xUnit, Reqnroll, Shouldly, Cypress, and Playwright Hands-on experience with GitLab CI/CD and GitHub Actions, including pipeline creation, modification, and test integration Practical experience with Git, including branches and merge requests Experience using Jira and Xray for test management, design, reporting, and traceability Knowledge of Grafana for dashboards, alerts, and monitoring key operational metrics Good SQL skills with PostgreSQL Very good command of English, both spoken and written Nice to have: Knowledge of Docker, Kubernetes, and OpenShift (OCP) Experience in performance testing using tools such as JMeter or k6 Knowledge of HTML, CSS, and JavaScript Proactive approach to analyzing business and technical requirements Ability to work closely with business stakeholders and development teams Practical experience with BDD methodology Ability to share knowledge and support junior team members Experience defining quality standards for software development and testing Openness to using AI tools such as Copilot, LLMs, and QA process automation solutions Offer: Private medical care Co-financing for the sports card Constant support of dedicated consultant Employee referral program

🏢 Summary: Senior Fullstack Developer role focused on delivering a React and .NET application for forecast ingestion, display, and user overrides. The position combines front-end and API development, Power BI embedding, Azure CI/CD collaboration, AI-assisted coding, and Agile delivery. 🗂️ Requirements: 5+ years of full-stack development experience, Experience delivering production web applications, Experience building custom React and .NET applications, Experience with Azure, Front-end and back-end development expertise, API design and integration experience, Experience or strong aptitude with AI-assisted coding tools, Experience working in Agile/Scrum, Fluent English, Strong communication and stakeholder-management skills, Ability to independently implement approved PRD, technical design, and Figma designs 📃 Skills: React, .NET, Azure, API, Codex, Copilot, Figma, Agile, Scrum, CI/CD 🏢 Description: As a recruitment company, DCG understands that every business is powered by experienced professionals. Our management style and partnership approach enable us to meet your needs and provide continuous support. Due to our ongoing growth and the large number of recruitment projects we undertake for our partners, we are currently looking for: Senior Fullstack Developer Responsibilities: Develop and maintain front-end features in React, based on approved Figma designs and technical specifications Build and integrate back-end services/APIs to support forecast ingestion, display, and user override functionality Embed and integrate the pre-built Power BI report into the application Use AI-assisted coding tools (Codex, GitHub Copilot) to accelerate development while maintaining code quality and standards Collaborate closely with the junior software engineer, providing technical guidance and code review support Work with DevOps support to manage deployments and CI/CD within Azure Participate in all Agile ceremonies: daily stand-ups, sprint planning, backlog refinement, and sprint reviews/retrospectives Take part in regular product showcases, presenting progress and demos to senior stakeholders Raise risks, blockers, or design questions early, working with the Product Manager and technical lead to resolve them Contribute to technical decisions and help refine the technical design as implementation progresses Requirements: Senior-level full-stack development experience (5+ years), with a strong track record of shipping production web applications Proven experience building custom React / .Net applications Solid experience with the Azure tech stack Confident working across front end and back end, including API design and integration Hands-on experience with, or strong aptitude for, AI-assisted development tools (e.g. GitHub Copilot, Codex) as part of daily workflow Comfortable working within an established Agile/Scrum framework Fluent English Strong communication skills; able to work effectively within a squad and engage confidently with senior stakeholders Ability to work independently against a completed PRD, technical design, and Figma designs, translating them into working software with minimal ambiguity Nice to have: Experience integrating or embedding Power BI reports into web applications (or comparable BI embedding experience) Experience working with or consuming outputs from ML models (e.g. forecast data) Offer: Constant support of dedicated consultant Employee referral program