Note: The job is a remote job and is open to candidates in USA. Cresta is on a mission to turn every customer conversation into a competitive advantage by unlocking the true potential of the contact center. The Senior Machine Learning Engineer will lead the design and development of next-generation AI systems, focusing on enhancing contact center operations through advanced machine learning techniques.
Responsibilities
- Lead the design and development of Cresta’s next-generation AI Agents and Agentic Assist systems, defining system architecture and core modeling approaches
- Architect intelligent, multi-step agent workflows that combine real-time guidance, knowledge retrieval, reasoning, summarization, and automated actions into cohesive production systems
- Design, deploy, and optimize LLM-powered systems, including Retrieval-Augmented Generation (RAG) pipelines, multi-agent orchestration, and domain-adapted models
- Improve reasoning, planning, and tool-use capabilities in real-world AI applications
- Develop evaluation strategies for complex, non-deterministic systems, including offline benchmarking, online experimentation, and LLM-as-a-judge methodologies
- Diagnose and mitigate real-world failure modes such as hallucinations, retrieval errors, tool misuse, prompt brittleness, and multi-step reasoning breakdowns
- Define and measure quality metrics (e.g., accuracy, faithfulness, task completion, latency, cost, robustness) to improve system reliability and performance
- Optimize AI systems for scalability, latency, security, and cost efficiency in production environments
- Collaborate cross-functionally with product, frontend, and backend teams to integrate AI capabilities seamlessly into Cresta’s platform
- Mentor engineers, contribute to technical strategy, and help shape the roadmap for Cresta’s AI systems
Skills
- Bachelor's degree in Computer Science, Mathematics, or a related field; Master's or Ph.D. preferred
- 5–8+ years of industry experience building and deploying machine learning systems in production, including significant experience working with LLMs
- Strong expertise in NLP, Generative AI, transformer architectures, embeddings, and retrieval systems
- Proven experience designing and deploying Retrieval-Augmented Generation (RAG) systems in enterprise environments
- Experience building and evaluating complex agentic or multi-step LLM workflows
- Strong knowledge of modern ML frameworks and tools (e.g., PyTorch, TensorFlow, Hugging Face) and distributed/cloud-based infrastructure
- Demonstrated ability to optimize real-time ML systems for performance, scalability, and reliability
- Strong technical leadership skills, with the ability to influence cross-functional decisions and raise the engineering bar
Benefits
- Comprehensive medical, dental, and vision coverage with plans to fit you and your family
- Flexible PTO to take the time you need, when you need it
- Paid parental leave for all new parents welcoming a new child
- Retirement savings plan to help you plan for the future
- Remote work setup budget to help you create a productive home office
- Monthly wellness and communication stipend to keep you connected and balanced
- In-office meal program and commuter benefits provided for onsite employees
- Offers Equity
Company Overview
Cresta uses artificial intelligence to assist sales and service agents in the quality of customer service. It was founded in 2017, and is headquartered in Sunnyvale, California, USA, with a workforce of 201-500 employees. Its website is https://www.cresta.com.Company H1B Sponsorship
Cresta has a track record of offering H1B sponsorships, with 2 in 2026, 9 in 2025, 6 in 2024, 2 in 2023, 10 in 2022, 4 in 2021, 3 in 2020. Please note that this does not guarantee sponsorship for this specific role.