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 be a key Staff-level architect building the "Digital Nervous System" that allows probabilistic LLMs to function as highly reliable, deterministic digital employees. This role is strictly dedicated to infrastructure, distributed state management, and multi-tenant scaling. You will partner with our AI Scientists who focus on model reasoning, cognitive architecture, and prompt engineering while you own the robust execution environments that allow their agents to operate safely in production. What You Will Architect Multi-Tenant Durable Agent Runtime: You will move beyond basic loops to architect fault-tolerant execution environments based on the principles of durable execution: incremental execution, state persistence, and fault tolerance via automated recovery. You will solve the complex challenges of long-running workflows, ensuring that transient network failures or server restarts never result in lost progress or phantom state crashes. Enterprise Memory Functions: Infinite context windows are a myth. You will design convergent, high-throughput memory infrastructures to support the working, episodic, semantic, and procedural memory tiers of our agents. This requires building state management systems capable of ultra-low latency retrieval and strict ACID transactions to maintain data integrity across thousands of concurrent sessions. Multi-Tenant Resource Isolation: You will ensure strict logical boundaries across shared infrastructure pools. This includes implementing zero-trust execution validation and native Row-Level Security within the database layer to completely isolate tenant context, preventing any possibility of cross-tenant data leakage. The Integration Fabric (MCP): You will drive our adoption of the Model Context Protocol (MCP), building the secure servers and clients that allow agents to dynamically discover tools, negotiate capabilities, and lay the groundwork for secure Agent-to-Agent (A2A) collaboration. Platform FinOps & Observability: You will establish the telemetry required to trace agent actions back to specific tenants, enforcing rate limits and optimizing the compute cost-per-token to ensure the unit economics of the platform remain highly viable. Who You Are Staff-Level Systems Thinker: You operate beyond tactical, day-to-day coding. You identify systemic architectural bottlenecks, define the technical direction for the platform, and mentor engineering teams on how to build for the age of agentic AI. Architectural Depth: You have extensive backend experience (Java, Go, or Python) and deeply understand the nuances of managing distributed state, event-driven architectures (Kafka), and non-deterministic execution in cloud environments. Reliability Expert: You understand that reliability in an AI system isn't just about uptime; it's about externalizing state, safe self-correction, and deterministic recovery. Protocol Aware: You are excited by open standards like MCP and understand the extreme complexities of API design, capability negotiation, and secure sandboxing for tool execution. Tech Stack Languages: Go/Java (Platform Services), Python (Integration Logic). Orchestration & State: Advanced durable execution frameworks and event-sourcing orchestration. Data: High-throughput in-memory datastores, converged databases, vector stores, Postgres, Kafka. Protocols: MCP (Model Context Protocol), gRPC, GraphQL. 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 [email protected] with your specific accommodation request.