Senior ML QA Engineer - Benchmark & Validate AI Stack in London

At Graphcore, we’re building the future of AI compute. We’re a team of semiconductor, software and AI experts, with deep experience in creating the complete AI compute stack – from silicon and software to infrastructure at datacentre scale. As part of the SoftBank Group, backed by significant long‑term investment, we are delivering key technology into the fast‑growing SoftBank AI ecosystem. To meet the vast and exciting AI opportunity, Graphcore is expanding its teams around the world. We are bringing together the brightest minds to solve the toughest problems, in a place where everyone has the opportunity to make an impact on the company, our products and the future of artificial intelligence.

Job Summary

Applicants for this role should have strong experience working with machine learning systems and frameworks, along with a solid understanding of core AI concepts and model behaviour. The role centres on testing, validating, and benchmarking a complex ML software stack, with a particular focus on performance, reliability, and correctness across modern AI workloads. The ideal candidate is an experienced ML engineer who understands how contemporary models are trained and executed, and who has hands‑on experience debugging functional and performance issues in ML systems. This person will be comfortable working with industry‑standard frameworks and state‑of‑the‑art models, bringing them up on internal infrastructure, and collaborating closely with software and hardware teams in a technically demanding environment spanning ML frameworks, infrastructure, and AI accelerator hardware.

The Team

The ML QA team is composed of highly skilled software engineers with a strong focus on automation, software quality, and data‑driven validation. The team works closely with industry‑standard machine learning frameworks and models, contributing to upstream open‑source projects and collaborating across the wider software organization. Operating in a fast‑paced environment, the team plays a critical role in ensuring reliability, performance, and maintainability across the ML software stack, helping to deliver robust and high‑quality products to customers.

Responsibilities and Duties

• Benchmark ML models and frameworks, analysing results to identify regressions, performance bottlenecks, and correctness issues.
• Work hands‑on with industry‑standard ML frameworks to validate functionality and performance across different execution environments.
• Build and maintain automated testing and benchmarking pipelines targeting simulators, emulators, and physical hardware.
• Collaborate closely with software teams to ensure adequate test coverage for new and existing features.
• Develop tooling and scripts (primarily in Python) to support testing, benchmarking, and functional reporting.
• Take ownership over aspects of our testing and infrastructure, owning the roadmap and driving innovation independently.

Candidate Profile

• Experience working in Machine Learning or ML‑adjacent engineering roles.
• Strong foundation in core AI and ML concepts (e.g. neural networks, training vs inference, numerical precision, performance trade‑offs).
• Hands‑on experience with one or more major ML frameworks such as PyTorch, TensorFlow, JAX, or similar.
• Strong proficiency in Python for ML workflows, experimentation, and automation.
• Experience designing, running, and analysing ML benchmarks or experiments.
• Experience working in Linux environments.
• Strong analytical and debugging skills, with the ability to reason about model behaviour and system performance.
• Bachelor/Master’s/PhD or equivalent experience in Computer Science, Maths, Machine Learning, Data Science, or related field.
• Experience with MLOps pipelines, model deployment, or production ML systems.
• Familiarity with performance analysis, profiling tools, or numerical accuracy validation.
• Exposure to distributed training or inference systems.
• Experience with hardware‑accelerated ML, compilers, or system‑level performance considerations.
• Familiarity with CI/CD systems used for ML workflows.
• Experience contributing to open‑source ML frameworks or tooling.

In addition to a competitive salary, Graphcore offers flexible working, a generous annual leave policy, private medical insurance and health cash plan, a dental plan, pension (matched up to 5%), life assurance and income protection. We have a generous parental leave policy and an employee assistance programme (which includes health, mental wellbeing, and bereavement support). We offer a range of healthy food and snacks at our central Bristol office and have our own barista bar! We welcome people of different backgrounds and experiences; we’re committed to building an inclusive work environment that makes Graphcore a great home for everyone. We offer an equal opportunity process and understand that there are visible and invisible differences in all of us. We can provide a flexible approach to interview and encourage you to chat to us if you require any reasonable adjustments. Applicants for this position must hold the right to work in the UK. Unfortunately at this time, we are unable to provide visa sponsorship or support for visa applications. We take pride in our commitment to creating an inclusive and diverse workplace.