Senior Machine Learning Engineer - Recommendations

Our Global Structure Deliveroo is now part of DoorDash, bringing together teams with even greater reach, scale, and ambition. Depending on your role, you may collaborate with teammates, systems, and leaders across DoorDash and Wolt. Together, we’re unlocking new possibilities as one global team. Join us in our mission to transform the way people shop and eat, where impact, innovation and growth drive everything we do. Our Global Engineering teams tackle complex technical challenges across a global, three-sided marketplace, building and scaling systems that serve millions of customers, riders and partners every day. We're looking for a Machine Learning Engineer to join our London office as part of a Global DoorDash Engineering team (working hybrid, 3 days in the office). Our New Verticals team exists to grow monthly active usage outside of restaurant ordering — groceries, retail, and everything in between. That means turning someone who only orders restaurant food into someone who also uses the app for a grocery run, and turning dormant users into active ones. You'll work on the surfaces that make that happen: the homepage, vertical landing pages, and the notifications that bring people back. This role sits closer to the personalisation and ranking side of that mission, working alongside colleagues across DoorDash, Deliveroo and Wolt. What You'll Be Doing Build and improve ranking models for vertical landing pages (grocery, retail), deciding what a user sees first when they land on a store page Design models that blend new-vertical content into a homepage built around restaurant ordering, without disrupting the core experience Build personalisation models that translate a user's existing behaviour into relevant recommendations for verticals they haven't tried yet Contribute to notification targeting — who gets notified, with what message, and when, to drive adoption of new verticals What You'll Need to Thrive Minimum 3+ years of experience as an ML Engineer or Data S

Perplexity is looking for a Search Machine Learning Engineer Intern to help build the next generation of advanced search technologies, with a focus on retrieval and ranking. You will work closely with experienced engineers to improve search quality, experiment with new models, and ship features that directly impact how users search and discover information. Internship program: 12 - 24 weeks, full-time, in-person in the London office. Responsibilities: Contribute to experiments that improve search quality through better models, data usage, and evaluation tools, under the guidance of senior engineers. Design and implement components of the search platform and model stack, including retrieval, ranking, and classification models. Train evaluating models (including LLM-based approaches) for retrieval, ranking, and classification tasks. Support deployment and monitoring of search and ranking models in a scalable and performant way. Help build and iterate on RAG pipelines for grounding and answer generation. Collaborate with Data, AI, Infrastructure and Product teams to deliver improvements quickly and learn best practices in production ML. Qualifications: Strong foundation in machine learning and statistics, with coursework or projects related to information retrieval, ranking, or recommender systems. Experience with Python and common ML frameworks (e.g. PyTorch, TensorFlow, JAX) through academic, open source, or personal projects. Familiarity with evaluating model quality using offline metrics and/or A/B testing is a plus, but not required. Previous experience (internships, research, or significant projects) working on search, recommendation, or NLP is a plus, but not required. Self-driven and curious, with a strong sense of ownership, willingness to learn, and comfort working in a fast-paced environment Experience with Rust will be a plus

We are hiring a Senior Machine Learning Engineer to contribute to cutting-edge Research & Development. As innovators in speech technology, our mission is to Understand Every Voice - a vision that has propelled us to be world leaders of Voice AI. Fuelled by innovation, inclusivity, and a passion for making a global impact through world-leading Speech AI, we're looking for an experienced Senior Machine Learning Engineer to accelerate our efforts towards exceptional speech solutions. Our Modelling Team trains diverse models, including large self-supervised ones, supporting Speechmatics towards being the most accurate speech recognition system globally. It also ensures their deployment into production, working with the latest developments in ML, but also with the best engineering practices for software engineering and model serving. What you’ll be doing: Work on complex R&D projects, with a diverse group of engineers, to achieve ambitious goals. Stay current with the latest developments in Machine learning. Execute high-impact projects to ensure team success. Work collaboratively across departments and mentor team members (where appropriate). Who we are looking for: Demonstrated experience in collaboratively pursuing ambitious R&D agendas. Precise attention to detail, but is also aware of how the big picture relates to company goals, and where the field of Machine Learning is headed towards. Understanding of the modern Machine Learning stack, for example: - Knowledge of contemporary transformer architectures (e.g., GQA, KV-caching) and best practices. - Experience in distributed training techniques. - Familiarity with optimisation strategies for model inference (e.g., dynamic batching, flash attention, speculative decoding). With preferred backgrounds covering some of the following: - Publications in top-tier conferences. - Contributions to popular open-source repositories. - Technical writing skills as evidenced by relevant publications or blogs. We en

Location: Bristol, London or Cambridge, UK About the job Help scale state-of-the art AI models across thousands of accelerators. As a Senior Machine Learning Engineer in the Applied AI team, you will contribute to advancing AI technology by developing and optimising new and existing AI models for our specialised hardware. You will work on large scale systems where performance is critical to the success of our projects. Having visibility of the entire pipeline from novel accelerator hardware to state-of-the-art AI applications, and the software stack in-between, you will play a critical role in identifying opportunities to innovate and differentiate Graphcore’s technology. Furthermore, you’ll work closely with researchers in a rapidly-evolving field, where even the most senior engineers are constantly learning and adapting to exciting new challenges. We seek engineers with strong technical foundations who are curious and eager to understand and advance AI model implementation, at scale. We currently have multiple opportunities available in the team at Senior, Staff and Principal level and offer flexibility through a hybrid working model, from any of our UK offices. If you're excited about advancing the next generation of AI models on cutting-edge hardware, we’d love to hear from you! The team and culture The Applied AI team’s role is to be proxies for our customers, we need to understand the latest AI models, applications, and software, as well as our own hardware and software stack, to ensure that Graphcore’s technology works seamlessly with the AI ecosystem and at scale. Our work spans from low-level kernel development and optimisation for novel hardware through to implementing and scaling research-level algorithms for the latest AI models. We collaborate with the Research team to develop and publish novel ideas in domains such as efficient compute, model scaling and di

Synthesia is the world’s leading AI video platform for business, used by over 90% of the Fortune 100. Founded in 2017, the company is headquartered in London, with offices and teams across Europe and the US. As AI continues to shape the way we live and work, Synthesia develops products to enhance visual communication and enterprise skill development, helping people work better and stay at the center of successful organizations. Following our recent Series E funding round, where we raised $200 million, our valuation stands at $4 billion. Our total funding exceeds $530 million from premier investors including Accel, NVentures (Nvidia's VC arm), Kleiner Perkins, GV, and Evantic Capital, alongside the founders and operators of Stripe, Datadog, Miro, and Webflow. About the role Synthesia Roleplay Sessions is a training tool that lets people practice real conversations with AI avatars. Instead of just watching training videos, learners do interactive roleplay exercises, like practicing a sales pitch or handling a customer complaint with an AI coach. The AI gives instant feedback so people know what they did well and what to improve. Managers can use a dashboard to track which employees have completed their training, see how well they performed, and measure if the training actually improved their skills. The whole platform is built around learning by doing rather than just passive video watching. For your ML engineer role, you'd be building the AI engine that makes the coaching work. That means creating the models that listen to what learners say during roleplay, score their performance, generate helpful feedback in real time, and decide how the AI avatar should respond next based on what the learner does. This is an applied ML position, not a research one . We expect you to have a good understanding of ML but on the other side to be a good product-focused software developer as you will be expected to work on different products. Please bring with you: Ability to apply your

Secure Every Identity, from AI to Human Identity is the key to unlocking the potential of AI. Okta secures AI by building the trusted, neutral infrastructure that enables organizations to safely embrace this new era. This work requires a relentless drive to solve complex challenges with real-world stakes. We are looking for builders and owners who operate with speed and urgency and execute with excellence. This is an opportunity to do career-defining work. We're all in on this mission. If you are too, let's talk. The UK&I Solutions Engineering team guides Okta customers through their entire journey, from initial engagement to upsell and cross-sell, using their expertise in presentations, events, and meetings to ensure customers drive maximum value from our platform. We are looking for great teammates that can build sales presentations, product demonstrations, and educate customers (everyone from developers to product managers to C-level executives) on Identity Security. Okta’s Solutions Engineers empathise with customers and quickly discern their true technical needs by asking detailed and clarifying questions and presenting solutions that target those needs. You have the rare combination of technical savviness and business insight and you’re looking for a career where you can utilise both. As a Solutions Engineer at Okta, you will hone each of these skills by advising a diverse set of customers on what is possible using Okta’s Identity Platform. What you’ll be doing: Involved in all stages of the customer’s sales lifecycle in the role of trusted technical advisor. Building sales presentations, product demonstrations, and educate customers (everyone from developers to product managers to C-level executives) on the best ways to secure identity. Empathise with customers and quickly discern their true technical needs by asking detailed and clarifying questions and presenting solutions that target those needs. Using your technical savviness and business