[Remote] Senior Machine Learning Engineer

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.ResponsibilitiesLead the design and development of Cresta’s next-generation AI Agents and Agentic Assist systems, defining system architecture and core modeling approachesArchitect intelligent, multi-step agent workflows that combine real-time guidance, knowledge retrieval, reasoning, summarization, and automated actions into cohesive production systemsDesign, deploy, and optimize LLM-powered systems, including Retrieval-Augmented Generation (RAG) pipelines, multi-agent orchestration, and domain-adapted modelsImprove reasoning, planning, and tool-use capabilities in real-world AI applicationsDevelop evaluation strategies for complex, non-deterministic systems, including offline benchmarking, online experimentation, and LLM-as-a-judge methodologiesDiagnose and mitigate real-world failure modes such as hallucinations, retrieval errors, tool misuse, prompt brittleness, and multi-step reasoning breakdownsDefine and measure quality metrics (e.g., accuracy, faithfulness, task completion, latency, cost, robustness) to improve system reliability and performanceOptimize AI systems for scalability, latency, security, and cost efficiency in production environmentsCollaborate cross-functionally with product, frontend, and backend teams to integrate AI capabilities seamlessly into Cresta’s platformMentor engineers, contribute to technical strategy, and help shape the roadmap for Cresta’s AI systemsSkillsBachelor's degree in Computer Science, Mathematics, or a related field; Master's or Ph.D. preferred5–8+ years of industry experience building and deploying machine learning systems in production, including significant experience working with LLMsStrong expertise in NLP, Generative AI, transformer architectures, embeddings, and retrieval systemsProven experience designing and deploying Retrieval-Augmented Generation (RAG) systems in enterprise environmentsExperience building and evaluating complex agentic or multi-step LLM workflowsStrong knowledge of modern ML frameworks and tools (e.g., PyTorch, TensorFlow, Hugging Face) and distributed/cloud-based infrastructureDemonstrated ability to optimize real-time ML systems for performance, scalability, and reliabilityStrong technical leadership skills, with the ability to influence cross-functional decisions and raise the engineering barBenefitsComprehensive medical, dental, and vision coverage with plans to fit you and your familyFlexible PTO to take the time you need, when you need itPaid parental leave for all new parents welcoming a new childRetirement savings plan to help you plan for the futureRemote work setup budget to help you create a productive home officeMonthly wellness and communication stipend to keep you connected and balancedIn-office meal program and commuter benefits provided for onsite employeesOffers EquityCompany OverviewCresta 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 SponsorshipCresta 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.