Principal AI Engineer

About Inworld

At Inworld, we believe that the benefits of AI should extend beyond business workflows to the applications and experiences that we enjoy every day. We began by pushing the frontier of lifelike, interactive characters for games and entertainment, pioneering realtime conversational AI ay, we apply that expertise to provide the multimodal models, pipelines and tools needed to build and evolve consumer-scale, real-time conversational AI applications across learning, health, social, assistants, games and media.

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 Linked In's Top 10 Startups in the USA.

Voice is one of the key interfaces humans will interact with AI  make this reality, we are building the engine for the next generation of AI-driven software. Our primary focus is pushing the boundaries of speech modeling (STT & TTS). We approach this by researching and utilizing ML ideas that allow us to achieve state-of-the-art results (we recently ranked #1 on Artificial Analysis for Text-to-Speech models).

Working with audio is uniquely complex - arguably more so than text - because the solution space for how a specific phrase can be spoken is effectively infinite. This creates a vast landscape of challenges, from data collection and efficient training infra to creating RL alignment environments and ultra-low latency inference optimizations.

We are seeking Staff and Principal level AI Engineers to solve these challenges. You will be responsible for researching, building, optimizing, and deploying the production ML systems that thousands of developers integrate with their systems. Your work will focus on the difficult research and engineering problems of building the engine for the next generation of AI-driven software.

Qualifications

• A PhD in a relevant technical field, or a BA/BS degree with equivalent research and/or engineering experience.

• 5+ years of combined experience in software development (e.g. with Python or C++) and applied ML engineering.

• Demonstrated experience applying or researching Machine Learning in one or more of the following domains:

• Speech or video processing

• Natural Language Processing (NLP)

• Action planning

• Strong foundation in data structures, algorithms, and neural network architectures.

• Proficiency with ML frameworks such as PyTorch.

• Professional working proficiency in English

A good fit for this role may have

• A passion for learning and staying up-to-date with the latest advancements in ML/Voice AI research and its applications.

• Ability to work collaboratively in a fast-paced environment with shifting priorities.

• Familiarity with pre-training, fine-tuning, RLHF and evaluation of large language and speech models.

• Knowledge of working with embedded systems and/or running ML on edge devices.

• Strong background in mathematics and/or physics.

• Location: remote within Switzerland

• Employment type: Full-time, permanent employment

• Hiring model: Employment via Employer of Record (EOR)

Candidates must already have the legal right to work in Switzerland. Visa or work‑permit sponsorship is not available for this role.

Optional relocation support to the United States may be available for candidates who are interested in relocating in the future and who meet applicable eligibility and immigration requirements. Any relocation and employment in the United States would be subject to separate review, legal authorization, and business approval.