Site Reliability Engineer / Performance Engineer in Cambridge

About Us

Visa is a world leader in payments technology, facilitating transactions between consumers, merchants, financial institutions and government entities across more than 200 countries and territories, dedicated to uplifting everyone, everywhere by being the best way to pay and be paid. At Visa, you'll have the opportunity to create impact at scale - tackling meaningful challenges, growing your skills and seeing your contributions impact lives around the world. Join Visa and do work that matters - to you, to your community, and to the world. Progress starts with you.

At Featurespace, we strive to be the world's best software company at protecting our clients and their customers from fraud attacks. We do that with personality, heart and professionalism, cultivating an innovative, fun and positive team atmosphere where everybody can contribute to solving our clients' problems in new, innovative ways. We are always seeking to be the best at what we do and make our customers smile.

Our real-time Financial Fraud Detection platform processes massive volumes of streaming and historical data. To meet our ambitious performance and scalability goals, we are looking for a Systems Performance Engineer with expertise in JVM tuning, distributed systems optimisation, and AWS infrastructure performance.

The Role

• Participating in daily standups and team meetings to synchronise activities with the team and keep investigations aligned with ongoing priorities.
• Leading analysis of Engineering Triage tickets, supporting Support teams by diagnosing issues raised by customers and helping identify root causes.
• Interpreting logs, metrics, and customer-provided data to understand system behaviour and identify potential misconfigurations or bottlenecks.
• Setting up, running, and evaluating Proofs of Concept (POCs) to validate configuration changes, new tools, or new approaches.
• Analysing graphs, resource usage patterns, and system-level data to draw clear, evidence-based conclusions.
• Tuning and enhancing our system configurations to improve reliability, scalability, and efficiency.
• Providing structured, data-driven recommendations to development teams.
• Investigating system-level issues in collaboration with engineering, support, and operations stakeholders.
• Conducting exploratory research, testing hypotheses, and leveraging web resources, documentation, and internal knowledge to resolve complex problems.
• Contributing to the continuous improvement of internal diagnostics, tooling, analysis processes, and investigation playbooks.

Role Responsibilities

• Investigate and analyse issues raised through Engineering Triage, using system-level data, metrics, logs, and customer information.
• Interpret graphs, measurements, and test results to identify patterns, anomalies, or bottlenecks.
• Set up, run, and compare POCs in controlled environments to validate hypotheses and guide technical decisions.
• Apply strong Linux and shell scripting knowledge to gather data, run tests, and automate routine analysis.
• Use JVM knowledge to understand system behaviour, resource utilisation, and configuration impacts.
• Tune and enhance the current system setup by recommending configuration, architectural, or operational adjustments.
• Research complex technical problems independently and propose practical, evidence-based solutions.
• Document findings clearly and communicate technical explanations to developers, support engineers, and stakeholders.

Impact

• Drive clarity on ambiguous or customer-reported system issues by producing high-quality investigations.
• Provide insights that directly influence system stability, performance, and customer satisfaction.
• Guide Support and Engineering teams by asking the right questions and helping interpret data.
• Deliver POCs that help the organisation evaluate new tools, architectures, or solutions with confidence.
• Influence technical direction by identifying structural or configuration improvements.

Behaviour

• Demonstrate a proactive, self-starting attitude-comfortable exploring issues independently before seeking help.
• Embrace a scientific mindset: formulate hypotheses, test them, evaluate results objectively.
• Show curiosity, enthusiasm, and a genuine interest in learning more about systems, tuning, and diagnostics.
• Collaborate effectively across teams and communicate findings clearly and constructively.
• Seek and provide timely, actionable feedback.
• Help raise the overall standard of system analysis, investigation quality, and diagnostic understanding across the team.
• Model a calm, methodical approach to complex or unclear problems.

Qualifications

• Strong understanding of Linux internals, shell scripting, and system-level diagnostics.
• Foundational JVM knowledge (memory, threads, GC basics, configuration impacts).
• Experience interpreting logs, metrics, dashboards, and system graphs.
• Ability to understand and interpret test results, workload outputs, and benchmark data.
• Proven ability to troubleshoot complex technical problems by researching, analysing, and synthesising information.
• Demonstrated use of a home lab or personal systems projects (VMs, clusters, network setups, custom builds).
• Strong analytical and critical-thinking skills with high attention to detail.
• Ability to manage workload independently and drive investigations to completion.
• Familiarity with common tooling for monitoring, metrics, or system insights.

Preferred Qualifications

• Database knowledge (relational or NoSQL).
• Deeper JDK/JVM tuning or diagnostic experience.
• Basic Kubernetes setup or cluster experimentation experience.
• Understanding of networking fundamentals.
• Experience with open-source tools used for diagnostics, observability, or system performance.
• Basic programming ability (any language) to support automation or small tooling improvements.
• Exposure to distributed systems concepts or cloud environments.

As a System Performance Engineer, you also need the following qualities:

• Attention to detail, excellence and quality.
• A focus on personal achievement and responsibility.
• Passion to learn new skills and technologies.
• Ability to share knowledge.
• Enthusiasm and an open mindset.
• Can-do attitude.

Visa is an EEO Employer. Qualified applicants will receive consideration for employment without regard to race, colour, religion, sex, national origin, sexual orientation, gender identity, disability or protected veteran status. Visa will also consider for employment qualified applicants with criminal histories in a manner consistent with EEOC guidelines and applicable local law.