Senior Machine Learning Engineer

Job Description

The Mission: The enterprise software landscape is fracturing. We are transitioning from "Systems of Record" to "Systems of Action." Zendesk is leading this shift with the Resolution Platform, aiming to be the first CX company to secure $1B in AI-driven revenue. To achieve this, we must solve the "Orchestration Trap." We are not just building features; we are building the high-performance runtime that allows fleets of AI Agents to Perceive, Reason, and Act.

The Opportunity: You will operate at the cutting edge of large language models, planning algorithms, and multi-agent coordination. By designing advanced memory structures and autonomous learning mechanisms, you will bridge the gap between offline model capabilities and dynamic, real-world task execution.

What You Will Architect & Research

• Building the World's Best Task Agents: You are tasked with achieving state-of-the-art performance against the industry's most rigorous benchmarks. You will optimize our agentic workflows to push past the 2026 frontiers, targeting elite-level autonomous problem solving on complex multi-step tool-use benchmarks.
• Advanced Memory & Cognitive Architectures: You will design sophisticated memory systems inspired by human cognition, allowing agents to dynamically filter interference, maintain context, and leverage long-term historical knowledge effectively across extended interactions.
• Trajectory Analysis & Reasoning Refinement: You will analyze complex agentic AI trajectories and trace patterns to understand how models navigate non-deterministic, multi-step problems. By leveraging these insights, you will build systems that capture the agent's entire chain-of-thought, analyzing conditional branches to actively detect anomalies and halt hallucination loops prior to failure.
• Self-Improving Loops & Skill Discovery: You will architect scalable, autonomous self-improving loops that allow agents to operate and learn continuously without human intervention. You will design frameworks where tool search patterns, error handling, and sophisticated retry logics are actively fed back into the system to dynamically improve the structure of the agentic AI planner. This includes enabling agents to autonomously discover, synthesize, and incrementally acquire new reusable skills based on environmental feedback and task completion.
• Enterprise Guardrails & Content Safety: You will engineer multi-layered defenses to secure agentic workflows against unique risks such as tool misuse, cascading action chains, and unintended control amplification. This includes designing strict input validation to block malicious prompt injections or jailbreak attempts, as well as output filtering to ensure responses remain within the application's domain boundary.
• Supervisor Patterns & Governance: You will implement governance-centric architectures, such as supervisor or manager agent patterns, to explicitly regulate actions and decision sequences during runtime. You will enforce capabilities-based access, ensuring that an agent's available tools are strictly determined by the user's role, and align system evaluations with compliance standards like the NIST AI Risk Management Framework.
• Rigorous Agentic Evaluation: You will move beyond static leaderboards to build continuous, multi-turn evaluation frameworks. You will design preference data pipelines to rigorously test emergent multi-agent coordination, ensuring our agents act safely and align perfectly with enterprise intent.

Who You Are

• Senior-Level AI Engineer You possess a deep foundation in machine learning, transformer architectures, and applied agentic systems. You have a history of designing real-world AI applications and leveraging agentic frameworks to build reliable, multi-step automated workflows.
• Cognitive Systems & Safety Thinker: You understand that building a great agent requires orchestrating specification, adaptive planning, tool execution, and iterative synthesis while embedding strict policies directly into the agent loop. You know how to decompose high-level goals into actionable, verifiable sub-tasks.
• Data-Driven Evaluator: You are obsessed with the science of evaluation and know how to close the distribution mismatch between how an agent performs in a sandbox versus how it behaves when navigating the ambiguity of real-world production.

Tech & Research Stack

• Frameworks & Languages: Python, PyTorch, and applied agent frameworks (e.g., LangChain, LangGraph, or similar orchestration tools).
• Evaluation: Custom LLM simulators, continuous multi-turn evaluation environments, and automated failure analysis pipelines.

The intelligent heart of customer experience

Zendesk software was built to bring a sense of calm to the chaotic world of customer service. Today we power billions of conversations with brands you know and love.

Zendesk believes in offering our people a fulfilling and inclusive experience. Our hybrid way of working, enables us to purposefully come together in person, at one of our many Zendesk offices around the world, to connect, collaborate and learn whilst also giving our people the flexibility to work remotely for part of the week.

As part of our commitment to fairness and transparency, we inform all applicants that artificial intelligence (AI) or automated decision systems may be used to screen or evaluate applications for this position, in accordance with Company guidelines and applicable law.

Zendesk is an equal opportunity employer, and we’re proud of our ongoing efforts to foster global diversity, equity, & inclusion in the workplace. Individuals seeking employment and employees at Zendesk are considered without regard to race, color, religion, national origin, age, sex, gender, gender identity, gender expression, sexual orientation, marital status, medical condition, ancestry, disability, military or veteran status, or any other characteristic protected by applicable law. We are an AA/EEO/Veterans/Disabled employer. If you are based in the United States and would like more information about your EEO rights under the law, please click here.

Zendesk endeavors to make reasonable accommodations for applicants with disabilities and disabled veterans pursuant to applicable federal and state law. If you are an individual with a disability and require a reasonable accommodation to submit this application, complete any pre-employment testing, or otherwise participate in the employee selection process, please send an e-mail to peopleandplaces@zendesk.com with your specific accommodation request.