Senior Machine Learning Engineer - Voice Experience

Stack

Responsibilities

• ▹Design, train, evaluate, and deploy ML systems powering real-time voice experiences (ASR, speech understanding, turn detection, TTS, summarization)
• ▹Improve voice AI quality through error analysis, data curation, metric design, and iterative model improvement
• ▹Build evaluation frameworks for complex voice and agentic systems (accuracy, robustness, latency, naturalness)
• ▹Diagnose and mitigate failure modes across the voice stack (transcription errors, hallucinations, retrieval failures)
• ▹Design and optimize low-latency ML workflows for live conversations
• ▹Partner with platform and backend engineers to productionize real-time inference and streaming pipelines
• ▹Mentor engineers and contribute to technical strategy for Cresta's voice AI systems

Requirements

• ▹Bachelor's degree in Computer Science, Mathematics, Machine Learning, AI, or related field; Master's or Ph.D. preferred
• ▹5+ years of experience building, evaluating, and deploying ML systems in production
• ▹Strong background in speech recognition, speech processing, NLP, generative AI, or conversational AI
• ▹Deep experience with model evaluation, benchmarking, and error analysis for production ML systems
• ▹Strong expertise with modern ML frameworks (PyTorch, TensorFlow, Hugging Face)
• ▹Solid understanding of transformer-based models, embeddings, and retrieval systems
• ▹Experience designing and deploying real-time ML systems with latency, scalability, and reliability requirements

Nice to have

• ▹Hands-on experience with ASR quality metrics (e.g., WER)
• ▹Experience with RAG systems, agentic workflows, or LLM-as-a-judge evaluation methods
• ▹Familiarity with streaming inference or real-time voice pipelines
• ▹Experience working closely with infrastructure or platform teams
• ▹Experience in contact center AI, conversational intelligence, or enterprise voice products

Soft skills

What we offer

• ▹Comprehensive medical, dental, and vision coverage
• ▹Flexible PTO
• ▹Paid parental leave
• ▹Retirement savings plan
• ▹Remote work setup budget
• ▹Monthly wellness and communication stipend
• ▹In-office meal program and commuter benefits
• ▹Base salary: $205,000–$270,000 + equity

About the company

Cresta unlocks the true potential of the customer experience with its unified AI platform combining conversational AI agents, real-time human agent augmentation, and conversation intelligence. Born from the Stanford AI Lab, it has raised over $270 million from leading investors.