Senior Fullstack Engineer, Auctions

Alt is unlocking the value of alternative assets, starting with the $5 B trading-card market. They are seeking a Senior Fullstack Engineer to build the engine behind a marketplace that moves hundreds of millions of dollars in GMV, focusing on high-scale transaction systems and cutting-edge AI.

Responsibilities:

• Architect the Auction Engine: Build and scale the high-concurrency bidding and listing systems that power 9-figure annual GMV
• Ship AI-Powered Liquidity: Develop next-gen features that leverage AI to provide instant valuations and upfront liquidity to our consignors and sellers
• Personalize the Hobby: Use data and machine learning to build rich, personalized discovery experiences that match unique collectibles to the right buyers
• Empower Power Users: Design and launch sophisticated management tools for everyone from high-frequency "power sellers" to veteran hobbyists
• Own the Experience: Build end-to-end—from the low-latency backend logic required for live bidding to the sleek, responsive UI where the action happens
• Drive Technical Excellence: Mentor the team and set the standard for code quality, system reliability, and performance

Requirements:

• 5+ years of experience building and scaling complex applications (Python, Postgres, AWS/Cloud infra)
• Modern Frontend Mastery: Deep experience with React, TypeScript, and building high-performance, real-time UIs
• Reliability Under Pressure: You have a track record of building systems that stay up when the stakes (and the traffic) are highest
• Data-Driven Mindset: Experience working with personalization engines, recommendation systems, or AI/ML integrations is a major plus
• Product Instincts: You don't just build what's on the ticket; you understand the collector mindset and build features that delight them