About Inworld
Inworld is a research lab of top researchers and engineers, building the world’s top-ranked realtime voice models.
Today our models are the #1 ranked realtime voice models in the world. They are used to power the largest consumer-facing AI applications available, across categories like health, fitness, learning, therapy, companions, customer experience and media; representing 100s of millions of end users. Our work spans areas like research and development of state-of-the-art models, optimizing realtime inference, and creating best-in-class APIs and products that allow developers to engage their users.
We’ve raised more than $125M from Lightspeed, Section 32, Kleiner Perkins, Microsoft’s M12 venture fund, Founders Fund, Meta and Stanford, among others. Our technology has powered experiences from companies such as NVIDIA, Microsoft Xbox, Niantic, Logitech Streamlabs, Wishroll, Little Umbrella and Bible Chat. We’ve also been recognized by CB Insights as one of the 100 most promising AI companies globally and have been named one of LinkedIn’s Top 10 Startups in the USA.
Who We're Looking ForA year ago, reliably working agentic systems barely existed. Nobody has a decade of experience here. So we're not screening for a resume template — we're looking for strong people from varied backgrounds who learn fast, thrive in ambiguity, and can show us what they've built, broken, and understood.
Experience We Find UsefulYou don't need all of this. But you need enough to make a case.
Foundation models: training, new architectures, RL, reward modeling, scaling
Evaluation: benchmarks, eval loops, quality measurement, LLM-as-judge, failure analysis
Frontier topics: multimodal models, agents, tool use, test-time compute, world models
Published research at ICML, ICLR, NeurIPS, EMNLP, ACL, or AAAI
PhD in ML/NLP — or equivalent practical experience you can point to
Public work: non-trivial AI side projects, interdisciplinary experiments, open-source contributions
Full-stack research ownership: you frame the question, run the experiments, write the paper, ship the result
If you learned through building, competitions, or collaborations outside academia — that counts. We care about evidence, not credentials.
Who Thrives HerePathfinders: You don’t need a roadmap to start walking; you’re comfortable picking a direction and building the map as you go.
Full-Cycle Researchers: You believe research isn't finished until it’s shipped. You have a bias for impact over purely academic output.
First-Principles Engineers: You don't just ship code; you obsess over the why. You’re the first to question an approach if you think there’s a better way to solve the core problem.
Mission Owners: You aren't satisfied with "the PM said so." You thrive on deep context and want to understand the fundamental logic behind every decision we make.
We hand you unclear problems and expect you to make them clear. We value researchers who say "I don't know yet" — and then design the experiment that finds out. We treat evaluation as a first-class research product, not a box to check before launch. Impact comes before publications though we support sharing work that moves the field forward. Your work should be visible. Flat structure, fast iterations, minimal process theater.
We don't need a cover letter. A link to something you've built tells us more.
The base salary range for this full-time position is £140,000 – £200,000. In addition to base pay, total compensation includes equity and benefits. Within the range, individual pay is determined by work location, level, and additional factors, including competencies, experience, and business needs. The base pay range is subject to change and may be modified in the future.
Candidates must already have the legal right to work in the United Kingdom, as visa sponsorship is not available for this role. For candidates interested in relocating to the San Francisco Bay Area in the future, full U.S. visa and relocation support may be available, subject to business needs and applicable legal and work authorization requirements.
Skills Required
- PhD in ML/NLP or equivalent experience
- Experience with foundation models and training
- Published research in top AI conferences
- Full-stack research ownership
- Non-trivial AI side projects
What We Do
Inworld is a fully integrated platform for AI characters that goes beyond large language models (LLMs) – by adding configurable safety, knowledge, memory, narrative controls, multimodality, and more. Inworld uses advanced AI to build generative characters whose personalities, thoughts, memories, and behaviors are designed to mimic the deeply social nature of human interaction. The Inworld platform lets you create characters with personality and contextual awareness to keep them in-world and on brand. Integrations make it easy for developers to deploy characters into immersive experiences, while scale and performance are optimized for real-time experiences. We are a team of experts that have pioneered conversational AI platforms and generative models at API.AI (acquired by Google and renamed Dialogflow), Google and DeepMind. We are continuing to build out our incredibly talented team, with experts in generative language models, emotions, speech synthesis, multimodal interaction, design, and 3D animation. Inworld is backed by top-tier investors including Section 32, Intel Capital, BITKRAFT Ventures, Kleiner Perkins, Founders Fund, First Spark Ventures, The Venture Reality Fund, CRV, Meta, Microsoft’s M12 fund, Micron Ventures, LG Technology Ventures, NTT Docomo Ventures, and SK Telecom Venture Capital. Inworld was one of six companies selected for the 2022 Disney Accelerator. Prominent angels include Twitch Co-Founder, Kevin Lin; Oculus Co-Founder, Nate Mitchell; Animoca Brands Co-Founder, Yat Siu; The Sandbox Co-Founder, Sebastien Borget and NaHCO3, the family office of Riot Games Co-Founder, Marc Merrill.
