Staff Frontend Software Engineer

At Twelve Labs, we are pioneering the development of cutting-edge multimodal foundation models that have the ability to comprehend videos just like humans do. Our models have redefined the standards in video-language modeling, empowering us with more intuitive and far-reaching capabilities, and fundamentally transforming the way we interact with and analyze various forms of media.

With a remarkable $107 million in Seed and Series A funding, our company is backed by top-tier venture capital firms such as NVIDIA’s NVentures, NEA, Radical Ventures, and Index Ventures, and prominent AI visionaries and founders such as Fei-Fei Li, Silvio Savarese, Alexandr Wang and more. Headquartered in San Francisco, with an influential APAC presence in Seoul, our global footprint underscores our commitment to driving worldwide innovation.

We are a global company that values the uniqueness of each person’s journey. It is the differences in our cultural, educational, and life experiences that allow us to constantly challenge the status quo. We are looking for individuals who are motivated by our mission and eager to make an impact as we push the bounds of technology to transform the world. Join us as we revolutionize video understanding and multimodal AI.

We’re hiring a Senior Frontend Engineer to build high-performance, video and data-centric agentic applications. This is a frontend-first role with end-to-end ownership, requiring strong UX craft, performance instincts, and enough backend fluency to collaborate on APIs, authentication, and real-time data flow.

You’ve built complex, multi-state UIs that feel fast and intentional. You care deeply about polish, usability, and performance, and you’re comfortable collaborating across the stack while spending most of your time in the browser.

This role may require participation in on-site interviews and/or completion of in-person onboarding processes.

Frontend (Primary)

• Build performant, polished experiences with React and Next.js

• Lead and evolve client-side architecture for interactive, video- and data-streaming products

• Build fluid, asynchronous UIs with strong performance, micro-interactions, and intentional motion

• Translate Figma designs into production-ready interfaces

• Implement and optimize browser-based video and real-time data streaming

• Build UIs that respond to incremental, real-time, or long-running streamed data, not just request/response flows

• Handle large video and data workloads within browser constraints (memory, buffering, network variability)

• Make informed tradeoffs around video formats, codecs, streaming, and transport

• Optimize rendering for complex timelines, lists, and canvases

• Write reliable unit, integration, and E2E tests for complex UI workflows

• Use AI-assisted development tools thoughtfully to accelerate implementation while maintaining correctness, performance, and code quality
  

Backend (Supporting)

• Design and integrate clean, well-scoped APIs to support streaming and async frontend workflows

• Implement and integrate authentication flows (sessions, tokens, role-based access)

• Collaborate with backend engineers on data models, streaming strategies, and performance tradeoffs

• 8+ years building production frontend applications

• Deep experience with React and modern frontend patterns

• Strong experience with Next.js & Tanstack Query
  Strong client-side performance and UX instincts

• Use of component libraries like shadcn & material ui

• Experience building browser-based video and data streaming experiences

• Working knowledge of HTML5 video APIs and streaming concepts

• Comfort working across the stack and making pragmatic tradeoffs

• Candidates must be able to travel up to 10% of the time annually to attend conferences, off-site meetings, and other business-related events as required by the role.

• Experience with editors or timeline-based interfaces

• Optimizing large or real-time datasets in the browser

• Familiarity with Vercel and frontend-focused CI/CD

• Comfort using Docker for local development

• Experience with AI- or ML-powered product features

🤝 An open and inclusive culture and work environment.

🚀 Work closely with a collaborative, mission-driven team on cutting-edge AI technology.

🏥 Full health, dental, and vision benefits

✈️ Extremely flexible PTO and parental leave policy. Office closed the week of Christmas and New Years.

🛂 VISA support where applicable