Senior Performance Engineer
Jit Team
⚲ Gdynia, Warszawa, Rzeszów, Kraków, Gdańsk
1 200 - 1 500 PLN/dzień netto (B2B)
Wymagania
- Gatling
- AppDynamics
- Kafka
- Apache JMeter
Opis stanowiska
Why choose this offer? • International working environment • Freedom in terms of collaboration between team members • Scandinavian organizational culture providing you with work-life balance • Getting to know how does the financial products and market works Project We are looking for a Senior Performance Engineer to join our team embedded within a major European financial infrastructure provider. The ideal candidate combines deep performance engineering expertise with a strong production support mindset, capable of operating independently across complex distributed systems in a regulated financial environment. This role requires someone who can own the full performance lifecycle: from test design and execution through production observability, bottleneck identification, and root cause analysis. Key Responsibilities Performance Testing & Analysis • Design, develop, and execute performance test scenarios for complex financial trading and clearing systems • Build and maintain performance test suites using tools such as k6, JMeter, Gatling, or equivalent • Analyze test results to identify throughput limits, latency bottlenecks, resource saturation, and concurrency issues • Produce clear, data-driven performance reports with actionable recommendations for development and infrastructure teams • Establish and maintain performance baselines, SLAs, and regression detection criteria Production Observability & Incident Support • Build and maintain dashboards and alerting using observability platforms (e.g. Prometheus, Grafana, Splunk, AppDynamics, or similar) • Perform real-time production triage and root cause analysis during performance incidents • Correlate metrics across application, infrastructure, and network layers to isolate degradation sources • Support capacity planning by analyzing production traffic patterns, growth trends, and resource utilization • Collaborate with SRE, infrastructure, and development teams to resolve performance issues in production Architecture & Advisory • Provide performance-focused input during architecture reviews and design discussions • Identify systemic performance risks in distributed architectures (microservices, messaging, databases) • Advocate for performance engineering best practices across the organization • Contribute to the evolution of the performance engineering toolchain and methodology Required Technical Skills Core Performance Engineering • 10+ years of hands-on performance engineering experience, preferably in banking or financial services • Expert-level proficiency in at least one performance testing tool (e.g. k6, JMeter, Gatling, Locust), or demonstrated ability to leverage AI-assisted development to rapidly build and ensure quality of test scripts in any of these tools • Good understanding of HTTP/REST, WebSocket, and messaging systems (e.g. Kafka, MQ). Familiarity with FIX protocol is a plus • Experience with load modeling, workload characterization, and capacity planning • Proficiency in at least one scripting language for test automation (e.g. JavaScript/TypeScript, Python, or Bash) Observability & Monitoring • Production experience with at least one APM tool (e.g. AppDynamics, Dynatrace, New Relic, or equivalent) • Hands-on experience with metrics and monitoring platforms such as Prometheus and Grafana, or equivalent observability stack • Experience with centralized log management and analysis (e.g. Splunk, ELK, or similar) • Understanding of distributed tracing concepts and tools (e.g. OpenTelemetry, Jaeger, Zipkin) Infrastructure & Platform • Working knowledge of Linux systems administration and performance tuning (CPU, memory, I/O, network) • Experience with containerized environments (e.g. Docker, Kubernetes) • Familiarity with CI/CD pipelines and integrating performance tests into delivery workflows • Exposure to cloud platforms and/or infrastructure-as-code tools is a plus Data & Analysis • Strong analytical skills with the ability to interpret complex datasets and correlate multi-signal performance data • Experience with SQL databases and understanding of database performance tuning (e.g. query optimization, indexing, connection pooling) • Comfortable working with time-series data, percentile analysis, and statistical methods for performance assessment Desired Qualities & Soft Skills • Self-starter who can operate independently with minimal supervision in a client-facing contractor role • Excellent written and verbal communication skills in English; ability to produce clear technical reports and present findings to senior stakeholders • Proactive problem-solver who takes ownership of issues from detection through resolution • Experience working in regulated environments (e.g. banking, financial markets, exchanges) with an understanding of change management and audit requirements • Collaborative mindset with the ability to work across distributed, multicultural teams • Continuous learner with interest in emerging technologies such as AI/ML for observability, cloud-native performance patterns, or chaos engineering Nice to Have • Experience with financial market infrastructure (exchanges, clearing houses, settlement systems) • Familiarity with FIX protocol and low-latency trading systems • Knowledge of OpenTelemetry and modern observability standards • Experience building custom performance analysis tooling or automation frameworks • Contributions to open-source performance or observability projects • ISTQB Performance Testing certification or equivalent Client – why choose this particular client from the Jit portfolio? Jit Team is proud to partner with one of the leading European financial groups responsible for the registration, ownership records, and financial settlement of securities traded on financial markets in Norway and recently extended to other European markets. Jit Team has been a strategic partner to our client in the area of software development since 2017. Over the course of the partnership, Jit Team's dedicated team working for our client has grown from three to over 30 people, who have worked on the modernization of legacy applications, the implementation of new systems, and the development of a private cloud-based platform to host a variety of financial systems.