Senior Lead Machine Learning Engineer (Agentic AI)

TL;DR

Senior Lead Machine Learning Engineer (Agentic AI): Architect, ship, and scale next-generation agentic intelligence including multi-agent systems, LLM training, evaluation, and runtime orchestration. Focus on building reliable, safe, and high-performing AI agents and platform backend infrastructure with strong leadership and mentorship responsibilities.

Location: Toronto, Ontario, Canada (onsite)

Company

Upwork Inc. connects businesses with global AI-enabled talent and provides a platform for contingent work including freelance and payrolled engagements.

What you will do

• Design and implement multi-agent systems with robust guardrails and recovery strategies.
• Lead LLM training, alignment, evaluation, and safety tuning for agent workflows.
• Architect and ship backend infrastructure for low-latency inference, orchestration, and developer APIs.
• Optimize cost and performance through quantization, distillation, and autoscaling.
• Provide technical leadership, mentor senior engineers, and influence product roadmaps.
• Publish internal guidance and contribute to technical content and reference architectures.

Requirements

• Must be located in Toronto, Canada or able to work onsite.
• Senior experience in applied ML and ML systems with LLM-powered product delivery.
• Strong software fundamentals in distributed systems, microservices, and APIs.
• Fluency in Python; proficiency in Go, Java, or JavaScript is a plus.
• Experience with container orchestration, messaging/streaming, and observability.
• Proven leadership and mentoring skills with excellent communication.

Culture & Benefits

• Opportunity to work with a leading AI-powered global work marketplace.
• Access to resources, culture, and growth opportunities within Upwork’s team.
• Competitive benefits offered through a partner during initial employment phase.
• Commitment to diversity, inclusion, and equitable workforce.