Senior Machine Learning Engineer

Fdetimes; United States; Remote; USD 205,000 - 270,000; Full time

Benefits offered by this job

Medical coverage

Dental coverage

Vision coverage

Flexible PTO

Parental leave

Retirement plan

Remote work setup budget

Wellness stipend

Meal program

Job summary

Cresta seeks a seasoned Machine Learning Engineer to build and scale next‑gen AI Agents and Agentic Assist systems. You’ll architect multi‑step workflows combining real‑time guidance, retrieval, reasoning, and automated actions into production systems.

Responsibilities include deploying LLM-powered pipelines, improving tool use, and defining evaluation metrics. You’ll collaborate across product and engineering teams and mentor others in a fast‑growing AI platform.

Qualifications

• Bachelor's degree in CS, Mathematics, or related field (Master's/PhD preferred).
• 5-8+ years building ML systems in production, including significant experience 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.
• Proficient with modern ML frameworks (PyTorch, TensorFlow, Hugging Face) and cloud-based infrastructure.

Responsibilities

• Lead design and development of Cresta's AI Agents and Agentic Assist systems, defining architecture and core modeling approaches.
• Architect intelligent, multi-step agent workflows with real-time guidance, retrieval, reasoning, and automation.
• Design, deploy, and optimize LLM-powered systems including RAG pipelines and multi-agent orchestration.
• Improve reasoning, planning, and tool-use capabilities in real-world AI applications.
• Develop evaluation strategies for complex, non-deterministic systems and LLm-as-a-judge methods.
• Diagnose and mitigate failure modes such as hallucinations, retrieval errors, and prompt brittleness.
• Define and measure quality metrics (accuracy, faithfulness, latency, cost) for reliability.
• Collaborate with product/frontend/backend teams to integrate AI capabilities into Cresta's platform.
• Mentor engineers and help shape the roadmap for Cresta's AI systems.

Skills

LLMs

NLP

Transformer architectures

RAG systems

Realtime ML systems

Leadership

Education

Bachelor's degree in CS/Math

Master's or PhD preferred

Tools

PyTorch

TensorFlow

Hugging Face

Job description

Cresta unlocks the true potential of the customer experience, turning every conversation into a competitive advantage. Cresta's unified AI platform combines conversational AI agents, real-time human agent augmentation, and comprehensive conversation intelligence to drive revenue and efficiency gains across every channel. The world's leading companies, including United Airlines, Cox Communications, and Marriott, use Cresta to power world-class customer experiences every day.

Born from the Stanford AI Lab, Cresta has raised more than $270 million from the world's leading investors, including a16z, Greylock, and Sequoia. Cresta's leadership includes some of the leading minds in AI today. Our CEO, Ping Wu, founded and led Google's Contact Center AI and Vertex AI platforms before joining Cresta to build the future of AI-driven customer experiences.

Over the next few years, AI is going to redefine how people all over the world interact with businesses every day. Come build that future at Cresta.

About the role

Machine Learning Engineers at Cresta work across several high-impact AI initiatives. Final team placement is determined based on experience, strengths, and business needs.

Current focus areas include

• Agentic Assist: Lead and build next-generation agentic AI systems that augment contact center agents in real time. This track requires strong pre-LLM ML foundations, deep expertise in LLMs and modern prompting techniques, a rapid prototyping mindset, and a proven ability to translate cutting-edge research into scalable, production-grade systems.
• Agent & System Quality: Design evaluation frameworks and improve the reliability, robustness, and performance of LLM-powered agents. This includes diagnosing and mitigating failure modes such as hallucinations, retrieval errors, tool misuse, context drift, prompt brittleness, and multi-step reasoning breakdowns, while defining measurable quality metrics (e.g., accuracy, faithfulness, task completion, latency, and cost) for complex, non-deterministic systems.
• Insights: Architect and scale LLM and retrieval-augmented generation pipelines that ground models in enterprise data. This track focuses on building high-performance ML systems that process complex data, extract structured insights, and deliver real-time, actionable intelligence at scale.

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.

Qualifications We Value

• 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.

Perks & Benefits

We offer a comprehensive and people-first benefits package to support you at work and in life:

• 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

Compensation at Cresta

Cresta's approach to compensation is simple: recognize impact, reward excellence, and invest in our people.

The posted base salary range represents what we expect to pay for this role in a given location. Final offers are shaped by factors like experience, skills, education, and geography. In addition to base pay, total compensation includes equity and a comprehensive benefits package for you and your family.

Salary Range: $205,000-$270,000 + Offers Equity

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