Senior Software Engineer II, Page Builder (Retailer Platform)

We're transforming the grocery industry At Instacart, we invite the world to share love through food because we believe everyone should have access to the food they love and more time to enjoy it together. Where others see a simple need for grocery delivery, we see exciting complexity and endless opportunity to serve the varied needs of our community. We work to deliver an essential service that customers rely on to get their groceries and household goods, while also offering safe and flexible earnings opportunities to Instacart Personal Shoppers. Instacart has become a lifeline for millions of people, and we’re building the team to help push our shopping cart forward. If you’re ready to do the best work of your life, come join our table. Instacart is a Flex First team There’s no one-size fits all approach to how we do our best work. Our employees have the flexibility to choose where they do their best work—whether it’s from home, an office, or your favorite coffee shop—while staying connected and building community through regular in-person events. Learn more about our flexible approach to where we work. Overview The Page Builder team is part of Instacart’s Retailer Platform organization within Core Experience Engineering. We own the content infrastructure that powers every consumer-facing page at Instacart—from the storefront homepage a shopper lands on, to the digital flyer they browse, the loyalty rewards they redeem, and the seasonal campaigns that drive purchases. Our systems operate at meaningful scale: the Content Management Domain (CMD) stores, resolves, and renders 150K+ active placements across 125+ format types and serves approximately 7 million placement fetches per day at roughly 200 RPS for 100+ retail partners. We’re looking for a Senior Software Engineer to lead high-impact platform initiatives that accelerate every team building on Instacart’s content layer. You will architect and drive the extraction of CMD from a Ruby monolith into a dedicated Go service, design proto-first API contracts used by many partner teams, and deliver low-latency, highly reliable services with clear SLOs. You’ll also shape a new composable content architecture that replaces 125+ hardcoded placement types with a single extensible type built on React components and Liquid templates—dramatically speeding up time-to-value for enterprise retailers and internal teams. This role is a force multiplier across Instacart. You’ll collaborate closely with Shopping/URSA, Feeds, Growth, Loyalty, and Ads to evolve CMD into a dependable, well-documented platform. You’ll help define our AI-native future by exposing Page Builder capabilities as MCP-compatible endpoints so AI agents can create, preview, QA, and publish pages end-to-end. If you thrive in fast-paced, high-ownership environments and enjoy rolling up your sleeves to solve complex, high-scale platform problems, you’ll feel right at home here. This role is open to candidates based in Canada (remote). About the Job Lead the CMD service extraction: architect and drive the migration of our Content Management Domain from a Ruby monolith into a dedicated Go service using a strangler-pattern approach; design proto-first API contracts (e.g., v2/GetPlacements), implement concurrent visibility condition evaluation via goroutines, and establish formal SLOs (99.9% availability, under 30ms P90 placement fetch) for a system handling 7M daily requests across 15+ consumer surfaces. Design composable extensibility: replace 125+ hardcoded placement format types with a single composable type built on React components and Liquid templates to eliminate weeks of full-stack engineering per new format and unlock enterprise retailer customization at scale. Shape the AI-native content platform: expose Page Builder capabilities as MCP-compatible endpoints, enabling AI agents to create, preview, QA, and publish pages end-to-end; define how LLM-powered content creation, AI carousels, and agentic page mana ... (truncated, view full listing at source)