Machine Learning Engineer, Voice Conversion

As a Machine Learning Engineer on Cantina's Speech Team, you'll build state-of-the-art speech systems end-to-end, from data specifications through production inference. You'll drive the model, data, and evaluation flywheel for voice conversion and adjacent tasks like controllable TTS and voice design, working at the intersection of cutting-edge research and practical engineering to ship fast, reliable, and cost-aware models.

What you'll do

• Architect, implement, pre-train, fine-tune, and post-train/align large-scale speech models using techniques like GRPO and DPO
• Design, run, and analyze scientific experiments to advance your understanding of the models
• Define data requirements and collaborate on acquisition, curation, augmentation, labeling quality, and synthetic data strategies
• Design automated objective and subjective evaluations, including listening tests, SV/WER/ASR-based metrics, robustness and bias checks, and red-team studies
• Harden the training, evaluation, and inference pipeline; profile latency, memory, and cost; and meet production SLAs with robust monitoring and rollback
• Contribute to safety and consent guardrails and to misuse and abuse mitigation for responsible speech technology
• Develop and improve developer tooling to enhance team productivity
• Contribute across the entire stack, from low-level optimizations to high-level model design

What you bring

• Exceptional research and development experience with large-scale audio models (over 8B parameters and over 500k hours of data)
• Deep hands-on experience with diffusion and/or flow-matching transformers, including practical knowledge of samplers, schedules, conditioning mechanisms, and distillation
• Deep hands-on experience training audio VAEs, neural audio codecs, and vocoders, including latent/tokenizer design, reconstruction and perceptual objectives, and adversarial training
• Strong experience with multi-node, multi-GPU distributed training using FSDP, DeepSpeed, or equivalent
• Strong software engineering skills and a proven track record of building complex systems
• Strong proficiency with PyTorch and performance work (profiling, CUDA, Triton, C++ as needed) and writing reliable production-quality code
• A track record shipping large-scale speech, audio, or multimodal generative models to production
• Background working with large-scale ML data and the ability to iterate on data quality using both subjective and objective signals
• Experience with voice cloning, speech control/steerability, or expressive speech generation
• Notable publications and/or open-source contributions in speech, audio, or ML

What we offer

• Competitive salary and generous company equity
• Medical, dental, and vision insurance with 99.99% of premiums covered by Cantina
• 42 days of paid time off: 15 PTO days, 10 sick days, 15 company holidays, and 2 floating holidays
• Generous parental leave and fertility support
• 401(k) retirement savings plan
• Lifestyle spending account of $500 per month
• Complimentary lunch and snacks for in-office employees
• One Medical membership

About Cantina

Cantina is a social platform founded by Sean Parker featuring advanced AI character creators. The platform lets you create lifelike, social bots that interact across voice, video, and text, enabling personalized content and group chat at scale.