A headless D2C replatform that took LCP from 4.9s to 1.6s

Kesari & Co. sells ayurvedic skincare direct to consumers — 2,300 SKUs once you multiply shade by size, ₹40 crore of annual GMV, and 74% of their traffic arriving on a mid-range Android phone over a patchy 4G connection. They had outgrown their Shopify theme in every way at once.

The storefront was the bottleneck

Largest Contentful Paint on a Redmi-class device over throttled 4G was 4.9 seconds. Core Web Vitals were failing on every template that mattered. The cause was clear: fourteen Shopify apps each added their own scripts, and the storefront was sending ~900 KB of JavaScript before a single product image appeared. Every app had been added to solve a real problem, and together they were the problem.

Three constraints an off-the-shelf theme could not satisfy

• Their promotion logic had outgrown the platform. They wanted build-your-own-routine bundles with tiered discounts, subscribe-and-save, and a loyalty tier multiplier — as rules the marketing team could write themselves. The discount tools in their theme could not do this. So they ran promotions by making and deleting variants by hand. In one Diwali campaign this created a bundle that could be bought for less than the cost of one of its parts.
• Inventory truth lived somewhere else. Stock was copied from their 3PL's warehouse system every six hours. During a flash drop, six hours is far too long. They sold 400 units more than they had of a top SKU on one launch and spent three weeks apologising.
• ONDC was coming. They wanted to list on the Open Network for Digital Commerce without adding a second, different catalogue to the side of the business. They also did not want network traffic anywhere near the buying path that pays the bills.

The request they came with was "rebuild our store". The plan we agreed on was narrower and more useful: take the storefront off the platform's page-making path, move promotions into a rules engine, make stock live, and make ONDC an adapter, not a copy.

We switched over in two stages. Collection and product pages came first, on 20% of traffic for eleven days, then the rest. There was no single risky weekend switch.

Speed turned directly into revenue

• LCP on a mid-tier Android over throttled 4G: 4.9s → 1.6s. All Core Web Vitals green, on mobile, on the pages that carry the traffic — not just on the homepage that everyone tests.
• Mobile conversion rate rose 34% over the eight weeks after the full switch, measured against the same mix of traffic. Nothing else changed in that time: no new ads, no new discounts, no new way of bringing in customers. This is the clearest proof we have ever had of the value of a fast storefront.
• 80% less JavaScript sent before first paint. The number that mattered more to them: their marketing team can no longer add 60 KB of blocking script by mistake by installing an app, because there are no apps.
• Zero oversells across the next four flash drops, including one that sold 3,100 units in nine minutes. The reservation ledger held.

What changed for the business

Promotions that used to take a developer and two days now take a marketer and twenty minutes. The preview mode has caught three pricing mistakes before they reached a customer, including one that would have repeated the Diwali below-cost bundle almost exactly.

They went live on ONDC four months later. That was two weeks of work, not a rebuild, because the adapter was already there, speaking to the same catalogue. That is the whole reason for building it as an adapter, and it is worth more than any speed number on this page.