DDR & HBM Validation Engineer

Job Summary Reporting to the Memory Validation leadership team, the DDR & HBM Validation Engineer will be responsible for the bring-up, validation, characterization and debug of advanced memory subsystems used in next-generation AI compute platforms. The role will focus on DDR and HBM technologies, working closely with silicon design, firmware, characterization, platform and systems teams to ensure robust memory subsystem functionality, performance and reliability. The successful candidate will take ownership of significant validation activities, contribute to debug and root-cause analysis efforts, and help improve validation methodologies, automation and infrastructure. The Team The Memory Validation team sits within the Validation organisation and is responsible for the bring-up, validation, characterization and debug of memory subsystems across Graphcore silicon and platform products. The team supports DDR and HBM validation activities throughout the product lifecycle, from first silicon through production readiness. Engineers work closely with architecture, RTL, firmware, characterization, systems and platform teams to ensure memory technologies meet functionality, performance, reliability and performance objectives. Responsibilities and Duties Execute validation and bring-up activities for DDR and HBM memory subsystems Verify memory bring-up software, firmware and scripts against defined project requirements Debug firmware, hardware and system-level issues and contribute to root-cause analysis activities Analyse system logs, validation data and characterization results to identify failures and performance issues Perform PHY characterization and analog-level analysis during stress testing and validation activities Develop and execute functional, stress, performance and corner-case validation tests Perform signal integrity, voltage, frequency and timing measurements using laboratory instrumentation Characterize memory bandwidth, latency, training behaviour and subsystem stability across operating conditions Develop Python-based automation, test infrastructure and reporting tools to improve validation efficiency Collaborate with architecture, RTL, firmware and platform teams to investigate and resolve technical issues Contribute to memory subsystem debug activities spanning silicon, firmware, board and system domains Support development of validation methodologies, debug procedures and reporting frameworks Contribute to continuous improvement of validation infrastructure and engineering processes Support silicon characterization, production readiness and qualification activities Document validation results and communicate findings to the wider engineering team Candidate Profile Essential Strong experience validating DDR, LPDDR, HBM or related DRAM technologies Deep understanding of DRAM architecture, memory subsystem operation and memory controller functionality Experience with firmware, BIOS and Embedded C development Strong programming skills in C and Python Hands-on experience using laboratory equipment including oscilloscopes and related measurement instrumentation Experience interfacing with low-speed peripherals including GPIO, SPI, I2C and UART/serial interfaces Experience performing functional testing and signal measurements including voltage, frequency and timing analysis Strong knowledge of embedded systems and microcontroller-based platforms Hands-on experience with board bring-up and hardware validation activities Experience debugging complex hardware, firmware and system-level issues Experience performing silicon characterization and analysing validation results Strong analytical, diagnostic and problem-solving skills Excellent communication and collaboration skills with the ability to work effectively across multidisciplinary teams Desirable Experience with memory IP bring-up environments, firmware or validation software Experience with DDR or HBM PHY behaviour, memory controller architectures, training algorit