Lead Machine Learning Engineer - Search & Recommendations at Upwork

This role is ideal for a senior-level Machine Learning Engineer with deep expertise in search and recommendation systems. You should be a technical leader who understands the nuances of "memory modeling"—specifically how to track user intent, preferences, and behavior over time to improve personalization. Since this is an individual contributor lead role, you’ll need the hands-on skills to move from architectural design to production-ready deployments. A standout aspect of this position is the opportunity to work at the forefront of AI-driven marketplace dynamics. Based in Toronto, you will influence the core engine that connects millions of businesses with talent. Note that this role begins through a hiring partner as the company establishes its local hub, with the potential to transition to direct employment later, offering a ground-floor opportunity in a growing regional office. **You might be a good fit if you...** * Have a proven track record of deploying high-scale retrieval and ranking systems that moved the needle on business metrics. * Are obsessed with "temporal dynamics"—understanding how recency, frequency, and preference drift impact user experience. * Enjoy operating in ambiguity and can translate abstract concepts like "user intent" into stable ML features. * Are comfortable with the full ML lifecycle, from data pipelines to low-latency inference.