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 management integrate with CMD. Drive cross-team architecture: own the technical relationship with Shopping/URSA, Feeds, Growth, Loyalty, and Ads; lead API contract design, coordinate migration sequencing, and ensure CMD evolves as a reliable, well-documented platform that other teams can confidently build on. Mentor and multiply the team: raise the engineering bar across Page Builder by mentoring engineers, establishing robust design patterns, and contributing to a culture where AI-assisted development is the default. About You Minimum Qualifications 5+ years of professional software engineering experience. Strong backend engineering skills with production experience in Go, Ruby, Java, or similar systems-level languages. Proven track record designing and leading large-scale technical projects (e.g., service extractions, platform migrations, new system architectures consumed by multiple teams). Experience building and operating high-throughput, low-latency backend services (handling millions of daily requests, sub-100ms latency targets, formal SLOs). Experience with platform-focused API design (gRPC/Protobuf, GraphQL, or REST) consumed by downstream teams. Demonstrated ability to drive technical decisions across team boundaries, including leading design reviews, negotiating API contracts, and coordinating migrations. Experience mentoring engineers and elevating team-wide technical standards. Strong written and verbal communication skills, including authorship of technical design docs and presenting architecture to leadership and cross-functional partners. Preferred Qualifications Background with content management systems, page builders, or CMS infrastructure (content modeling, placement/component resolution, template rendering). Hands-on Go experience, including goroutines, channels, and building high-concurrency services. Monolith-to-microservice migration experience using patterns like strangler fig, dual-reads, or gradual traffic shifting. Experience building self-serve tooling for business users (merchants, retailers, marketers) where extensibility and reliability directly impact customer revenue. Experience with multi-tenant platform architecture serving diverse customers with shared infrastructure. Familiarity with AI/LLM integration patterns: MCP (Model Context Protocol), agent-based workflows, AI-generated content pipelines, or prompt-to-UI. Frontend experience with React/TypeScript (helpful, not required) given our span from backend infrastructure to WYSIWYG editor tooling. Experience at companies with analogous products or platforms (e.g., Shopify, Contentful, Builder.io, Webflow, DoorDash, Meta, Amazon). Experience with Protobuf/gRPC and proto-first API design. Familiarity with e-commerce or marketplace platforms, including retailer needs, storefront customization, and enterprise SaaS dynamics. #LI-Remote Instacart provides highly market-competitive compensation and benefits in each location where our employees work. This role is remote and the base pay range for a successful candidate is dependent on their permanent work location. Please review our Flex First remote work policy here. Currently, we are only hiring in the following provinces: Ontario, Alberta, British Columbia, and Nova Scotia. Offers may vary based on many factors, such as candidate experience and skills required for the role. Additionally, this role is eligible for a new hire equity grant as well as annual refresh grants. Please read more about our benefits offerings here. For Canadian based candidates, the base pay ranges for a successful candidate are listed below. CAN $196,000—$207,000 CAD