Senior Signal Integrity Engineer

About the role

Graphcore is seeking a Senior Signal Integrity Engineer to own the design and validation of high-speed signaling for next-generation compute systems. The role involves managing the complete signal integrity lifecycle, addressing challenges from the silicon and package through to the board and rack-level architectures. You will be responsible for ensuring robust electrical performance across complex multi-chip modules and dense interconnect environments. This position requires deep expertise in analyzing and optimizing high-speed interfaces under demanding conditions. The engineer will drive the development of methodologies that guarantee reliable operation at scale. Collaboration with cross-functional teams is central to succeeding in this role and delivering measurable improvements in system-level signal integrity. You will play a key part in defining the electrical foundation of Graphcore's machine intelligence platforms.

Key facts

What you'll do

• Perform comprehensive end-to-end signal integrity analysis for rack and blade system architectures, evaluating electrical behavior across the entire deployment stack.
• Optimize critical I/O interfaces including PCIe Gen4, PCIe Gen5, PCIe Gen6, Ethernet, DDR memory controllers, SerDes channels, SPI, and I2C implementations.
• Develop and execute detailed time-domain and frequency-domain simulations using industry-standard tools such as SPICE, Ansys HFSS, Keysight ADS, Cadence Sigrity, and CST.
• Plan and conduct lab validation activities using high-speed oscilloscopes, vector network analyzers (VNA), time-domain reflectometry (TDR), and bit error rate testers (BERT).
• Establish correlation between simulation models and physical measurements to identify performance gaps and drive iterative improvements in design methods.
• Work closely with silicon engineering, board design, and connector specialists to influence routing strategies, stack-up definitions, and system-level integration decisions.
• Interface with direct interconnect vendors and original design manufacturers (ODMs) to define and refine hardware specifications based on SI analysis.
• Prepare detailed technical documentation and present findings, validation reports, and design recommendations to engineering stakeholders and management.
• Lead troubleshooting efforts for signal integrity issues during development and qualification phases, applying advanced diagnostic techniques.
• Contribute to the establishment of signal integrity design rules, best practices, and standards across the organization.
• Support the development and validation of test fixtures, debug procedures, and characterization platforms for high-speed interfaces.
• Evaluate emerging high-speed interface technologies and assess their suitability for future Graphcore architectures.
• Collaborate with mechanical and thermal engineering teams to understand and mitigate interactions between physical layout and electrical performance.
• Mentor junior engineers and technical staff in signal integrity principles, measurement techniques, and simulation methodologies.

Requirements

• Hold a Bachelor or Master degree in Electrical Engineering, Computer Engineering, or a closely related technical discipline.
• Demonstrate professional experience in signal integrity engineering focused on high-speed digital systems and complex interconnects.
• Show proven proficiency in lab measurement techniques using time-domain reflectometry (TDR), vector network analysis (VNA), bit error rate testing (BERT), and high-speed digital oscilloscopes.
• Possess strong analytical skills to evaluate jitter characteristics, eye diagram metrics, S-parameter networks, impedance profiles, crosstalk mechanisms, and timing margin budgets.
• Have hands-on familiarity with high-speed interface standards and protocols including SerDes implementations, DDR memory interfaces, Ethernet PHYs, and PCI Express generations 4, 5, and 6.
• Demonstrate experience with SI and PI simulation and analysis software tools such as CST, Sigrity, Keysight ADS, HFSS, or SPICE-based environments.
• Exhibit strong technical communication abilities to prepare clear reports, deliver presentations, and collaborate effectively with multidisciplinary teams.
• Understand the fundamentals of electromagnetic behavior in printed circuit boards, package substrates, and connectors used in high-performance computing systems.
• Be capable of working independently and managing multiple engineering tasks in a fast-paced, deadline-driven environment.
• Align with Graphcore's commitment to building inclusive technologies and contributing to a diverse and respectful workplace.

Nice to have

• Bring a background gained from working in cloud infrastructure, data center platforms, or hyperscale computing environments.
• Have direct experience with backplane, blade, cable, or board-to-board interconnect solutions in demanding applications.
• Show understanding of how mechanical stresses, thermal gradients, and material properties influence signal integrity and power integrity outcomes.
• Demonstrate skills in fixture design, de-embedding techniques, automated test procedures, and calibration methodologies for measurement accuracy.
• Highlight scripting capabilities in MATLAB or Python to automate data analysis, post-process measurement results, and drive simulation workflows.

Practical notes

Graphcore provides a competitive salary and a benefits package including medical, dental, and vision insurance. The package also covers 401(k) plans, disability and life insurance, commuter benefits, health savings accounts, flexible spending accounts, and an Employee Assistance Programme. The company is committed to providing reasonable accommodations for candidates throughout the interview process and maintains a workplace that values inclusion and diversity.