Slingshot Bio

Slingshot Bio makes synthetic cell mimics: engineered particles that stand in for real T, B, and NK cells on any flow cytometer and hold steady where donor samples drift batch to batch. By the time they reached us they had outgrown their setup, a WordPress marketing site on one domain and a separate Shopify store on another, with no shared design, content model, or data between them. We were brought in to converge the two into one headless platform: Next.js and Sanity on Vercel, Shopify kept purely for checkout, built on turbo-start-shopify, our open-source Shopify and Sanity starter. Design through to launch in three months.

The storefront had to make a dense, technical catalogue easy to move through, so the science reads clearly and a researcher gets from landing page to cart without friction. We instrumented the entire path in PostHog and stitched identity across the headless boundary, so we can follow one session from first landing through to a completed Shopify checkout, even though checkout runs on a separate domain. Session replay sits on top, so the team can watch real researchers move through the site and see where a high-value order stalls or closes.

A scientific catalogue is unusually structured. Every control carries markers, reactivity, pack sizes, application notes, and a certificate of analysis, and a researcher needs to scan any product and know exactly what they are holding. We modelled all of it in Sanity, so each product is structured data rather than a hand-built page. Spec sheets, panels, and reactivity render from one source, and the team can publish a new product or COA without a developer. New entries slot into the system as the catalogue grows.

Underneath, it is a headless Shopify build. Sanity owns content, Shopify is reduced to checkout, and Next.js on Vercel keeps the full catalogue filtering instantly, even as families and markers are added. We also built for how labs actually buy. Most controls sell through a mix of cart and enquiry, and a purchase usually needs sign-off, so a researcher can turn a basket into an itemised, branded PDF and send it to a principal investigator or procurement to approve. The cart holds for weeks, so they can return and check out once the approval lands.

The cutover was seamless. We inventoried every page and resource across both old sites, mapped each to its new home, and built a custom Shopify theme whose only job is redirects, so nothing broke and the search equity carried across. The platform launched AI-ready: JSON-LD on every product, collection, and resource, content negotiation that serves clean Markdown to AI crawlers alongside the HTML, an llms.txt, a Markdown sitemap, and a sitemap whose timestamps track Sanity directly. Marketing publishes in Sanity, and the structured data, the sitemap, and the crawlable Markdown all stay current on their own.

The native Shopify basket waits on the server for every change. We replaced it with a headless commerce cart on Next.js that updates optimistically: add a control or change a quantity and the line items and total move at once, the price animating to its new value while Shopify's Storefront and Cart APIs confirm in the background. Nothing blocks on the round trip, so the basket reads as markedly faster than native Shopify. For a researcher assembling a multi-line order across panels and pack sizes, it keeps pace with how fast they work.