Staff Applied Machine Learning Engineer, SimGym

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Staff Applied Machine Learning Engineer, SimGym

• Remote - Americas
• Engineering & Data

About the role

About The Role

Shopify is building SimGym, an AI-powered store testing system that simulates buyer behavior using browser automation and LLM/VLM agents. SimGym helps merchants understand how real shoppers might experience their storefronts, then turns those simulations into trustworthy, merchant-facing theme insights and recommendations.

We are looking for a Staff Applied Machine Learning Engineer to set and drive the ML technical direction for SimGym. This is a senior technical leadership role for someone who can move between strategy and code: defining the roadmap, designing production ML systems, de-risking ambiguous research, mentoring senior engineers, and shipping model improvements that create real merchant impact.

You will work across multimodal browsing agents, teacher-model distillation, learned buyer personas, SFT/post-training, evaluation systems, behavioral data pipelines, and production rollout infrastructure. The goal is not just to improve benchmarks, but to build AI agents that behave more like real buyers and produce recommendations merchants can trust.

What You'll Do

• Own the ML technical direction across SimGym's agent, persona, evaluation, and data flywheel workstreams.
• Develop, fine-tune, evaluate, and deploy LLM/VLM-based systems for browser automation, buyer simulation, and storefront analysis.
• Lead major model initiatives from research prototype to production readiness, such as VLM teacher distillation, learned buyer personas, or SFT model rollout.
• Design scalable ML architectures, data pipelines, and model-serving systems that support experimentation, evaluation, and production deployment.
• Improve human-vs-agent alignment and behavioral fidelity through rigorous offline and online evaluation.
• Build and stabilize golden datasets, trace replay systems, screenshot/A11y-tree evaluation flows, and reliable benchmark infrastructure.
• Use Shopify-scale behavioral and storefront data to improve buyer simulation, personalization, and merchant-facing recommendations.
• Make clear build/buy tradeoffs across models, infrastructure, evaluation tooling, and data systems.
• Communicate technical direction and tradeoffs clearly with engineering, product, data, research, and partner teams.
• Raise the technical bar for the team through hands-on implementation, design review, mentorship, and pragmatic execution.

What You'll Need

• Staff-level applied ML leadership experience, with a track record of setting strategy, writing code and designs, unblocking teams, and delivering production systems through ambiguity.
• Strong hands-on experience with LLM, VLM, or agent systems, including SFT/post-training, distillation, evaluation, model iteration, and serving tradeoffs.
• End-to-end experience training, evaluating, testing, deploying, and operating ML products at scale.
• Strong instincts for experimentation and evaluation, including designing meaningful metrics, diagnosing alignment failures, and avoiding misleading benchmark wins.
• Experience building production ML data pipelines and working with large-scale behavioral, event, or product data.
• Proficiency with Python, shell scripting, batch and streaming data pipelines, orchestration tools, vector databases, BigQuery/BigTable or equivalent systems.
• Experience with parallel or distributed ML environments, including GPU optimization, model serving, or large-scale training/inference workflows.
• Excellent communication with technical and non-technical audiences.

Nice To Have

• Experience with browser automation, AI agents, or simulated user behavior.
• Background in e-commerce, search, recommendations, personalization, or buyer behavior modeling.
• Experience with sequence or behavior representation learning, recommender embeddings, HSTU-style architectures, vLLM/GPU serving, Spark/GCS/Hugging Face-style data workflows.
• Prior experience translating research prototypes into reliable, production user-facing systems.

Why This Role

This is a high-leverage role at the center of Shopify's applied AI work for merchants. You will help shape SimGym's ML architecture and operating model while working on frontier LLM/VLM agents, learned buyer personas, evaluation science, and production systems with direct merchant impact.

This role may require on-call work. Shopify's hiring process moves quickly, and candidates should be prepared for a technical interview loop that includes pair programming using their own IDE.

About Shopify

Opportunity is not evenly distributed. Shopify puts independence within reach for anyone with a dream to start a business. We propel entrepreneurs and enterprises to scale the heights of their potential. Since 2006, we’ve grown to over 8,300 employees and generated over $1 trillion in sales for millions of merchants in 175 countries.

This is life-defining work that directly impacts people’s lives as much as it transforms your own. This is putting the power of the few in the hands of the many, is a future with more voices rather than fewer, and is creating more choices instead of an elite option.

About you

Moving at our pace brings a lot of change, complexity, and ambiguity—and a little bit of chaos. Shopifolk thrive on that and are comfortable being uncomfortable. That means Shopify is not the right place for everyone.

Before you apply, consider if you can

• Care deeply about what you do and about making commerce better for everyone
• Excel by seeking professional and personal hypergrowth
• Keep up with an unrelenting pace (the week, not the quarter)
• Be resilient and resourceful in face of ambiguity and thrive on (rather than endure) change
• Bring critical thought and opinion
• Put AI agents and tools to work on the tasks they're built for, and focus on the work only humans can do
• Embrace differences and disagreement to get shit done and move forward
• Work digital-first for your daily work

We may use AI-enabled tools to screen, select, and assess applications. All AI outputs are reviewed and validated by our recruitment team.

Shopifyhttps://www.shopify.com

We hire people, not resumes. If you think you’re right for the role, apply now