Principal Engineer - AI

TCGplayer is seeking an exceptional Principal Engineer to define and drive our ML/AI technical strategy. This is a unique opportunity to shape how artificial intelligence and machine learning transform the trading card game marketplace experience for millions of collectors, players, and sellers. As our most senior individual contributor in ML/AI, you will bridge the gap between cutting‑edge AI capabilities and practical marketplace applications, translating complex ML concepts and emerging generative AI technologies into strategic roadmaps while maintaining the technical depth to prototype and validate architectural decisions.

Your scope encompasses both customer‑facing innovations and internal productivity transformations, leveraging AI to accelerate our software development lifecycle and operational excellence.

• Define TCGplayer’s multi‑year ML/AI technical strategy, identifying transformative opportunities across customer experiences and internal engineering productivity, with particular focus on practical applications of generative AI.
• Design the foundational AI/ML platform architecture that will scale from experimental implementations to production systems serving millions of users, supporting both traditional ML models and LLM‑based applications.
• Drive adoption of AI‑powered development tools and processes, accelerating software delivery through code generation, automated testing, intelligent debugging, and documentation assistance.
• Design and implement AI‑driven operational improvements, from intelligent monitoring and anomaly detection to automated incident response and capacity planning.
• Evaluate and prototype emerging AI technologies, particularly generative AI and LLMs, building proofs‑of‑concept to validate feasibility and impact before broader investment.
• Partner with engineering, product, and data teams to translate business objectives into AI‑powered capabilities, starting with intelligent site search and mobile deck‑building experiences that may leverage traditional ML and generative approaches.
• Establish AI/ML best practices, including model governance, ethical AI principles, performance benchmarking, prompt engineering standards, and operational excellence for deterministic and generative systems.
• Serve as the technical authority on AI/ML across the organization, educating both leadership and business stakeholders on the possibilities and limitations of both established ML techniques and emerging generative AI capabilities.
• Drive make‑vs‑buy‑vs‑partner decisions for AI infrastructure and capabilities, evaluating vendor solutions, foundation models, and APIs against custom development.
• Create technical platform specifications and architecture documents that enable other engineers to implement AI systems aligned with the overall strategy.

• 10‑12+ years of software engineering experience, with 5+ years specifically architecting and deploying ML/AI systems at scale.
• Demonstrated experience setting AI technical strategy and roadmaps in product‑driven organizations, with recent focus on integrating generative AI capabilities.
• Deep understanding of the full ML lifecycle alongside practical experience with LLM deployment, fine‑tuning, and prompt engineering.
• Proven ability to communicate complex technical concepts to diverse audiences, from engineers to executives, with clarity and impact.
• Track record of evaluating emerging technologies and making pragmatic architectural decisions balancing innovation with delivery, particularly in the rapidly evolving generative AI space.
• Experience designing AI platforms that democratize both traditional ML and generative AI capabilities across engineering teams.
• Expertise in multiple AI domains (NLP, computer vision, recommendation systems) plus hands‑on experience with transformer architectures, RAG systems, and production LLM deployments.
• Strong systems thinking with understanding of distributed systems, data pipelines, and production infrastructure for both traditional ML and token‑based generative models.

• Experience in e‑commerce marketplaces, particularly with search relevance,…