Senior Full Stack Engineer (Python / React / AWS) AI-Accelerated Development

Our client is an AdTech SaaS built on Shopify that helps e-commerce businesses run ads on Meta and Google, evolving into an AI-driven solution. We are seeking a Senior Full Stack Engineer to take real ownership of the product and drive the next stage of growth by building AI-native experiences and ensuring platform reliability.

• Stabilize, maintain, and build context within the existing platform
• Build AI-native experience: analyze merchant data, score products by predicted ROAS, and drive campaign decisions automatically
• Ensure deep Shopify integration so the product lives where merchants already work (Shopify admin, Sidekick, Flow)
• Improve platform reliability, UX, onboarding, ROAS optimization, and performance transparency
• Own QA as part of delivery: write specs with acceptance criteria, review AI-generated code, and ensure features are tested before release
• Work with AI-assisted development approach: spec, generate, review, refine, and ship

• 5+ years of production experience with Python and React
• Hands-on experience with AWS (EC2, RDS, S3, Lambda or similar)
• Comfortable owning the full stack (frontend, backend, infrastructure)
• Experience with Shopify API, Meta Marketing API, or Google Ads API
• Primary engineer experience with ability to make architectural decisions
• Ability to balance support and feature development
• Experience with AI coding tools (Cursor, Claude Code, Copilot)
• QA mindset: writing tests, conducting code reviews, validating before release
• Nice to have: Shopify app development, LLM APIs (OpenAI, Gemini), AdTech or performance marketing background

• Fully remote, flexible schedule
• Real equity as a key engineer at a pivotal stage
• Ownership over architecture and decisions
• Competitive salary
• Paid vacation
• Direct work with founders, no PM layer, minimal processes