[Hiring] Senior Applied Machine Learning Engineer @Shopify

Role Description

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 Senior Applied Machine Learning Engineer to lead high-value ML work within SimGym. This is a hands-on technical role for someone who can execute through ambiguity, write production-quality code, make strong technical decisions, and help turn model experiments into reliable systems with real merchant impact.

You will work on problems across:

• Multimodal browsing agents
• Teacher-model distillation
• Learned buyer personas
• SFT/post-training
• Evaluation systems
• Behavioral data pipelines
• Production rollout infrastructure

The goal is not just to improve benchmarks, but to help build AI agents that behave more like real buyers and produce recommendations merchants can trust.

Qualifications

• Strong applied ML engineering experience, with a track record of delivering production systems through ambiguous technical problems.
• Hands-on experience with LLM, VLM, or agent systems, including SFT/post-training, distillation, evaluation, model iteration, or serving tradeoffs.
• End-to-end experience training, evaluating, testing, deploying, and operating ML products at meaningful scale.
• Strong experimentation and evaluation instincts, including designing useful 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 working with parallel or distributed ML environments, including GPU optimization, model serving, or large-scale training/inference workflows.
• Strong software engineering fundamentals: code quality, operational awareness, maintainability, and speed of execution.
• Clear communication with both technical and non-technical audiences.

Requirements

• Lead high-impact ML projects within SimGym's agent, persona, evaluation, or data flywheel workstreams.
• Develop, fine-tune, evaluate, and deploy LLM/VLM-based systems for browser automation, buyer simulation, and storefront analysis.
• Move model improvements from experiment toward production readiness, such as VLM teacher distillation, learned buyer personas, or SFT model rollout.
• Design and build scalable ML components, data pipelines, and model-serving paths that are easy to understand, operate, and maintain.
• Improve human-vs-agent alignment and behavioral fidelity through strong offline and online evaluation practices.
• Contribute to 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.
• Diagnose complex model, data, and system failures with attention to the important details.
• Make practical technical tradeoffs across models, infrastructure, evaluation tooling, and data systems.
• Communicate clearly with engineering, product, data, research, and partner teams.
• Help raise the technical bar for the team through strong execution, thoughtful design, code quality, and mentorship by example.

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 in Shopify's applied AI work for merchants. You will help build the ML systems behind SimGym while working on frontier LLM/VLM agents, learned 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.