Principal Design Engineer Jobs

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. We’re looking for a Principal Engineer to join the ML Platform team at Synthesia. Our team builds and operates the systems that allow researchers and product teams to train, serve, and deploy generative models reliably and efficiently . This includes research infrastructure, production serving systems, internal tooling, and the platform interfaces that connect them. A growing part of our mission is making these systems more automation-friendly and agent-oriented , so that workflows can increasingly be operated through reliable tooling rather than manual effort. We’re looking for a strong generalist with a systems mindset: someone who is comfortable working across infrastructure, backend systems, and tooling, and who has seen ML systems in practice. this is not a pure ML Engineer role. We’re especially interested in people who think deeply about reliability, scalability, performance, and resource efficiency in complex production environments. This is a hands-on IC role with significant ownership. You’ll help shape how our ML platform evolves as we scale the number of models, workloads, tools and teams relying on it. What you’ll do Design and improve the platform systems that support model training, evaluation, an

Every day, tens of millions of people come to Roblox to explore, create, play, learn, and connect with friends in 3D immersive digital experiences– all created by our global community of developers and creators. At Roblox, we’re building the tools and platform that empower our community to bring any experience that they can imagine to life. Our vision is to reimagine the way people come together, from anywhere in the world, and on any device. We’re on a mission to connect a billion people with optimism and civility, and looking for amazing talent to help us get there. A career at Roblox means you’ll be working to shape the future of human interaction, solving unique technical challenges at scale, and helping to create safer, more civil shared experiences for everyone. As a Principal Enterprise Security Engineer, you will advance Roblox’s Enterprise Security strategy by shaping and evolving security architecture in alignment with business objectives. You will lead the design, deployment, and governance of security solutions that safeguard Roblox’s corporate infrastructure while enabling scalable, secure operations. Partnering cross-functionally with Corporate Engineering and Trust & Safety, you will translate organizational priorities into resilient security capabilities that balance risk, compliance, and productivity. You will join the Platform, Enterprise, and Application Security group, reporting directly to the Senior Manager of Enterprise Security Engineering. You'll partner with security professionals across the InfoSec team, and work cross-functionally with teams throughout Roblox to drive security initiatives that scale with our business. You will: Define and maintain enterprise-wide security standards and principles that guide how security is implemented across business workflows, ensuring consistency, scalability, and alignment with organizational risk posture. Lead and drive initiatives across core security domains, including Endpoint Secur

Every day, tens of millions of people come to Roblox to explore, create, play, learn, and connect with friends in 3D immersive digital experiences– all created by our global community of developers and creators. At Roblox, we’re building the tools and platform that empower our community to bring any experience that they can imagine to life. Our vision is to reimagine the way people come together, from anywhere in the world, and on any device. We’re on a mission to connect a billion people with optimism and civility, and looking for amazing talent to help us get there. A career at Roblox means you’ll be working to shape the future of human interaction, solving unique technical challenges at scale, and helping to create safer, more civil shared experiences for everyone. About the role: As a Principal Security Engineer on the Detection and Response (D&R) team at Roblox, you'll play a key role designing and developing effective custom security data pipeline systems, detection strategies and automations for response workflows to defend our critical assets from threat actors. You will also lead real-time incident response, actively investigate events and analyze threat actor techniques to prioritize emerging threats to ensure Roblox is equipped to mitigate and react to critical challenges. You will play a vital part to ensure the safety of our community and enterprise by proactively fostering a high-performing, inclusive security culture. This is a hybrid in-office role. You Will: Be a D&R authority! You will deliver robust detection & response capabilities: build new threat detection systems (keeping false positives low) while also automating processes with scripts, playbooks and orchestration tooling. Implement ETL pipelines : Design and develop customized data processing pipelines. Conduct security operations : Actively monitor security events and participate in on-call rotations to lead real-time incident response to contain and mitigate potent

Every day, tens of millions of people come to Roblox to explore, create, play, learn, and connect with friends in 3D immersive digital experiences– all created by our global community of developers and creators. At Roblox, we’re building the tools and platform that empower our community to bring any experience that they can imagine to life. Our vision is to reimagine the way people come together, from anywhere in the world, and on any device. We’re on a mission to connect a billion people with optimism and civility, and looking for amazing talent to help us get there. A career at Roblox means you’ll be working to shape the future of human interaction, solving unique technical challenges at scale, and helping to create safer, more civil shared experiences for everyone. As a Principal Security Software Engineer in the Enterprise Security team, you will advance Roblox's Enterprise Security strategy by building the systems and integrations that protect Roblox's corporate infrastructure. Where traditional security engineers evaluate and deploy vendor solutions, you will design and build production-grade security software - Identity and Access governance, policy enforcement engines, and security integrations that scale with Roblox's business. You'll partner with security professionals across InfoSec and work cross-functionally with Corporate Engineering, DevOps, and Product teams to drive security initiatives. You will: Build identity and access systems : Design, implement, and own integrations across Roblox's IAM ecosystem, including SSO federation, SCIM provisioning/deprovisioning pipelines, OAuth 2.0 authorization servers, and token lifecycle management. Lead security automation : Develop production-quality tools and services that enforce security policies at scale, replace manual workflows, and surface actionable signals Drive secure-by-design implementations : Partner with Corporate Engineering, DevOps, and product teams to embed security controls in

Every day, tens of millions of people come to Roblox to explore, create, play, learn, and connect with friends in 3D immersive digital experiences– all created by our global community of developers and creators. At Roblox, we’re building the tools and platform that empower our community to bring any experience that they can imagine to life. Our vision is to reimagine the way people come together, from anywhere in the world, and on any device. We’re on a mission to connect a billion people with optimism and civility, and looking for amazing talent to help us get there. A career at Roblox means you’ll be working to shape the future of human interaction, solving unique technical challenges at scale, and helping to create safer, more civil shared experiences for everyone. As a Principal Security Software Engineer on the Production IAM team, you will set the technical direction for how identity and access work across Roblox's production infrastructure, from the mTLS-based identity that services use to authenticate to one another, to the privileged access controls that govern how engineers reach production. The team is accountable for Roblox's machine and workload identity platform, its centralized authorization engine, its production access management platform, production PKI and certificate lifecycle, and just-in-time privileged access for engineers. As an individual contributor in Production IAM, you will define multi-year strategy, drive alignment across Roblox Platform, mentor senior and staff engineers, and personally build the hardest parts of these systems. As AI agents become first-class actors in production, you will also help pioneer how they get identity, prove who they are, and receive safely-scoped access. You will Lead the architecture for production identity and access. Define and evolve the end-to-end design for machine, workload, human, and AI-agent identity across our hybrid on-prem and cloud fleet, making secure access invisible when

Every day, tens of millions of people come to Roblox to explore, create, play, learn, and connect with friends in 3D immersive digital experiences– all created by our global community of developers and creators. At Roblox, we’re building the tools and platform that empower our community to bring any experience that they can imagine to life. Our vision is to reimagine the way people come together, from anywhere in the world, and on any device. We’re on a mission to connect a billion people with optimism and civility, and looking for amazing talent to help us get there. A career at Roblox means you’ll be working to shape the future of human interaction, solving unique technical challenges at scale, and helping to create safer, more civil shared experiences for everyone. ML Platform @ Roblox today supports hundreds of ML use cases and billions of inferences per day across Discovery, Safety, Engine, and much more. As a Model Optimization engineer on ML Platform, you will be responsible for digging deep into model internals to optimize performance, for both training and inference. We are looking for accomplished engineers to help us maximize performance of our platform. You Will: Optimize machine learning models for performance on GPU architectures, focusing on both training and inference workflows. Conduct low-level performance profiling analysis to identify bottlenecks in existing machine learning pipelines and propose actionable improvements. Contribute to the development of best practices and tooling for model optimization and deployment. Collaborate with cross-functional teams, including data scientists and software engineers, to integrate and deploy optimized models into production environments. Partner across organizations to build tooling, interfaces, and visualizations that make the ML@Roblox a delight to use. You Have: 6+ years of professional experience and a tool chest of system design experience upon which to draw to build performant system

Every day, tens of millions of people come to Roblox to explore, create, play, learn, and connect with friends in 3D immersive digital experiences– all created by our global community of developers and creators. At Roblox, we’re building the tools and platform that empower our community to bring any experience that they can imagine to life. Our vision is to reimagine the way people come together, from anywhere in the world, and on any device. We’re on a mission to connect a billion people with optimism and civility, and looking for amazing talent to help us get there. A career at Roblox means you’ll be working to shape the future of human interaction, solving unique technical challenges at scale, and helping to create safer, more civil shared experiences for everyone. As a Principal Machine Learning Engineer within the Creator Services Machine Intelligence team, you will focus on the research and development of Embodied AI and Behavioral Agents that revolutionize how games are created and played on Roblox. You will bridge the gap between cutting-edge research and massive-scale product application, building agents capable of complex 3D gameplay and unblocking many use cases across Roblox, from automated playtesting to ensure quality, to "ML Players" with human-like movement and strategic reasoning, playing with real players in games. You will work on feature extraction, model training, building validation / RL platform as well as inference set up leveraging methods from imitation learning to reinforcement learning. And you will create generalizable agents that can perceive 3D environments, understand game rules, plan long-term strategies, and execute complex physics-based actions in real-time. You Will: Design and implement foundation models end to end through the feature extraction to inference for embodied agents. Define the long-term roadmap for Game AI and Embodied Intelligence, acting as a technical bar-raiser for code quality and architectural desig

Every day, tens of millions of people come to Roblox to explore, create, play, learn, and connect with friends in 3D immersive digital experiences– all created by our global community of developers and creators. At Roblox, we’re building the tools and platform that empower our community to bring any experience that they can imagine to life. Our vision is to reimagine the way people come together, from anywhere in the world, and on any device. We’re on a mission to connect a billion people with optimism and civility, and looking for amazing talent to help us get there. A career at Roblox means you’ll be working to shape the future of human interaction, solving unique technical challenges at scale, and helping to create safer, more civil shared experiences for everyone. With Roblox Ads & Discovery business growing at a rapid rate, we are building large scale ads machine learning infrastructure to deliver more value to our users and our advertisers. As a Machine Learning Infrastructure Engineer, you’ll build scalable, reliable, and high-performance infrastructure that powers ML systems across our organization. You’ll operate at the scales of hundreds of billions of engagements, and redefine how we deliver performance ads to hundreds of millions of users. You will: You will co-design models and systems, working at the intersection of model architecture and ML infrastructure, partnering closely with core modelers, data and AI infrastructure engineers, and product teams to push the boundaries of large-scale training and serving. Your work will span recommendation, search, and agentic applications, including large transformer architectures, LLMs, generative rankers, and efficient offline and online content-understanding systems. You will investigate model, data, and systems tradeoffs end to end—from data pipelines and distributed training to low-latency inference and production serving. This includes designing efficient KV-cache strategies, applying p

Every day, tens of millions of people come to Roblox to explore, create, play, learn, and connect with friends in 3D immersive digital experiences– all created by our global community of developers and creators. At Roblox, we’re building the tools and platform that empower our community to bring any experience that they can imagine to life. Our vision is to reimagine the way people come together, from anywhere in the world, and on any device. We’re on a mission to connect a billion people with optimism and civility, and looking for amazing talent to help us get there. A career at Roblox means you’ll be working to shape the future of human interaction, solving unique technical challenges at scale, and helping to create safer, more civil shared experiences for everyone. Discovery UX sits at the intersection of product innovation and high-scale infrastructure. Every Roblox user starts their journey on the homepage, and every Roblox developer needs to find their correct audience. Our team works closely with product and engineering teams across Roblox to bridge this gap by improving the user journey from landing on Roblox to joining an experience. We primarily work on Home, Search, Charts, and Experience Details pages, for both the Roblox website and app. As a Principal Software Engineer , you will craft robust, extensible systems for high-traffic surfaces. While you are a frontend expert at heart, you are a versatile engineer who isn't afraid to dive into the backend or data pipelines to ship a complete feature. You will drive solutions using React and modern technologies, helping us build efficiently across devices. If you have a deep understanding of frontend architecture and a genuine curiosity for diving into data to understand "the why" behind an experiment, you will be right at home with us. This role reports to the Engineering Manager on the Discovery UX team. You Will: Design, build, and ship features that define the discovery journey for millions of

Every day, tens of millions of people come to Roblox to explore, create, play, learn, and connect with friends in 3D immersive digital experiences– all created by our global community of developers and creators. At Roblox, we’re building the tools and platform that empower our community to bring any experience that they can imagine to life. Our vision is to reimagine the way people come together, from anywhere in the world, and on any device. We’re on a mission to connect a billion people with optimism and civility, and looking for amazing talent to help us get there. A career at Roblox means you’ll be working to shape the future of human interaction, solving unique technical challenges at scale, and helping to create safer, more civil shared experiences for everyone. Why Connections? As a Principal Software Engineer on the Connections team, your work will power the Roblox ecosystem, helping people recognize and connect with friends & interests on Roblox, express themselves, and discover & engage with the best of Roblox through their connections. You will own critical features used by millions of users daily, including profiles, names, online presence, co-play tools, and social proof, while also developing new zero-to-one features. If you are an experienced developer who loves to write code, ship user-facing features, mentor engineers, up-level frontend development, and drive product vision, you’ll have the opportunity to make a meaningful impact on this team. This role is based at Roblox HQ in San Mateo, CA (no remote option). You Will: Design, build, and ship features that power the social graph for millions of users Architect scalable, long-term solutions Collaborate with teams across the company to translate ambitious business goals into a concrete, multi-year technical roadmap Serve as a technical leader, setting engineering standards and mentoring other engineers You Have: 8+ years of experience in software development with web

Every day, tens of millions of people come to Roblox to explore, create, play, learn, and connect with friends in 3D immersive digital experiences– all created by our global community of developers and creators. At Roblox, we’re building the tools and platform that empower our community to bring any experience that they can imagine to life. Our vision is to reimagine the way people come together, from anywhere in the world, and on any device. We’re on a mission to connect a billion people with optimism and civility, and looking for amazing talent to help us get there. A career at Roblox means you’ll be working to shape the future of human interaction, solving unique technical challenges at scale, and helping to create safer, more civil shared experiences for everyone. As a Principal Engineer in the Builder Tools team, you’ll work on interactive, developer-facing tools and reusable tooling frameworks for Roblox Studio, a collaborative IDE for making Roblox games. The Builder Tools team is in charge of Roblox Studio’s content making features, from 3D draggers to world-class character animation tools, tooling for making terrain for huge worlds, in-game UI authoring tools, and many more. In this role, you will have a direct impact on how streamlined and enjoyable making games on Roblox is for hundreds of thousands developers worldwide! You will: Work on various interactive tools for Roblox game developers Define architecture and implement reusable tooling frameworks Work with UX designers and Product Manager to come up with most optimal and ergonomic solutions Design and execute on the architecture and technical direction that will be the future of our application Own and deliver complex technical projects from the planning stage through execution Work cross functionally, across teams and technology platforms Mentor team members helping them improve their professional skills and expertise Design, develop, and implement technological p

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. Principal Forward Deployed Engineer, Okta for AI Agents About Okta for AI Agents Okta secures access for 20,000 organizations and billions of users. Okta for AI Agents extends that work to the agentic shift. Deploying an AI agent is not like deploying traditional software. You are putting professional work output into production, and it needs deep integration, continuous tuning, and change management. Every agent needs an identity, a scope, an audit trail, and a way to be shut down when it goes wrong. Most enterprises have not built this yet. We are. We hire builders who see the cracks in enterprise agent identity that everyone else has learned to live with. The Role You embed inside four to five of Okta’s most strategic enterprise customers as their dedicated technical partner for agent identity. You sit alongside their identity, platform, and security engineering teams, develop sample and bespoke code, and own the technical outcome from prototype through production. You are a builder-consultant. You go past architecture diagrams to code, debug, and ship bespoke agent identity solutions inside the customer’s environment. You ship secure agents faster for the customer, and you feed real field insight back to Okta product engineering. Responsibilities Become the customer’s trusted technical voice on agent security. Sit in their standups, design reviews, and incident reviews. Earn a seat on their architecture review board and security council for agent risk d

About Pinterest: Millions of people around the world come to our platform to find creative ideas, dream about new possibilities and plan for memories that will last a lifetime. At Pinterest, we’re on a mission to bring everyone the inspiration to create a life they love, and that starts with the people behind the product. Discover a career where you ignite innovation for millions, transform passion into growth opportunities, celebrate each other’s unique experiences and embrace the flexibility to do your best work. Creating a career you love? It’s Possible. At Pinterest, AI isn't just a feature, it's a powerful partner that augments our creativity and amplifies our impact, and we’re looking for candidates who are excited to be a part of that. To get a complete picture of your experience and abilities, we’ll explore your foundational skills and how you collaborate with AI. Through our interview process, what matters most is that you can always explain your approach, showing us not just what you know, but how you think. You can read more about our AI interview philosophy and how we use AI in our recruiting process here . Within the Ads Delivery team, we try to connect the dots between the aspirations of pinners and the products offered by our partners. In this role, you will be responsible for developing and executing a vision for the evolution of the Pinterest marketplace. You will design and implement systems that improve the ads delivery funnel, experiments that shape the utility function, auction mechanism design, ad allocation and for deriving new insights through analysis of the marketplace dynamics. In short, this is a unique position, where you’ll get the freedom to work to bring together pinners and partners in this unique marketplace. What you’ll do: Build and improve backend systems and statistical models that underlay the marketplace to maximize value for Pinners, Partners and Pinterest. Define and implement experiments to understand long term Market

About Ema Ema is building the world’s leading Agentic AI platform to transform enterprise productivity. We enable organizations to delegate repetitive tasks to Ema, the Universal AI Employee, delivering 10x gains in workforce efficiency, across functions. Founded by former executives from Google, Coinbase, Flipkart, and Okta, our team includes engineers from premier tech companies and graduates of Stanford, MIT, UC Berkeley, CMU, and IITs. We are backed by industry leading investors including Accel, Naspers/Prosus, Section32, and angels like Sheryl Sandberg and Dustin Moskovitz. Headquartered in Silicon Valley and with offices in London, Bangalore and Vancouver, Ema is at the frontier of what Agentic AI can do in production — we ship real systems that run real business processes at scale. Role Overview & Key Responsibilities This is a high-leverage leadership role that spans architecture, execution, and org-building, and will shape the direction of our AI / ML initiatives at Ema. We are seeking an AI / ML technical leader who can take a vision and build it. As a Principal ML Engineer at Ema, you will be a senior technical leader responsible for shaping the machine learning roadmap, architecting large-scale ML systems, driving innovation, and ensuring our mixture of expert models (LLM + SLM + Custom Model) is accurate and performant at scale. You will collaborate across teams (research, product, infra, data, etc.), mentor senior engineers, and influence strategy and execution at company-wide levels. Responsibilities Lead the technical direction of GenAI and agentic ML systems that power enterprise-grade AI agents — spanning reasoning, retrieval, tool use, and integrations across various SaaS products. Architect, design, and implement scalable production pipelines for model training, fine-tuning, retrieval (RAG), agent orchestration, and evaluation — ensuring robustness, latency efficiency, and continuous learning. Define and own the multi-year ML roadmap for GenA

At Snowflake, we are powering the era of the agentic enterprise. To usher in this new era, we seek AI-native thinkers across every function who are energized by the opportunity to reinvent how they work. You don’t just use tools; you possess an innate curiosity, treating AI as a high-trust collaborator that is core to how you solve problems and accelerate your impact. We look for low-ego individuals who thrive in dynamic and fast-moving environments and move with an experimental mindset — who rapidly test emerging capabilities to discover simpler, more powerful ways to deliver results. At Snowflake, your role isn't just to execute a function, but to help redefine the future of how work gets done. Streamlit in Snowflake (SiS) is our flagship app development platform, enabling data engineers, analysts, and developers to build and deploy interactive, data-driven applications directly within Snowflake. As Principal Engineer for the Streamlit in Snowflake team, you will be the top technical voice shaping how millions of users build and deploy apps on Snowflake's data platform. This role requires a rare combination: deep hands-on engineering expertise in Python/container runtimes, a systems architect's instinct for platform design, and the organizational influence to drive cross-team programs. You will define how SiS evolves from its container-native SPCS runtime and embedding/iframe SDK, to its developer experience, performance at scale, and integration with Snowflake's broader AI and data ecosystem. AS THE PRINCIPAL ENGINEER FOR STREAMLIT IN SNOWFLAKE YOU WILL: Define and own the architectural vision for the SiS platform spanning the SPCS container runtime, the warehouse runtime, the embedding SDK, developer tooling, and the Snowsight integration layer. Drive the platform's evolution toward its next-generation capabilities building on publicly shipping features like chromeless viewer URLs and IdP integration, and shaping the architectural direction for areas still in de