Most Shopify devs ship code.
Most CRO agencies don't ship code.
We do both.
Senior engineering executed with the rigor of a CRO team. Every build is instrumented. Every change is testable. The code is clean enough to hand to your next dev without an apology.
Four areas. One senior team.
Theme architecture that survives the next ten apps.
Custom Online Store 2.0 themes built with modern tooling — Vite, Alpine.js, no jQuery rot. Code your next dev won't have to rewrite.
Shopify Functions that move the needle, not the cart UI.
Cart transforms, custom discounts, delivery and payment customization. Native to Shopify. No app dependency, no checkout flicker.
Subscription work past the off-the-shelf widget.
Recharge and Skio — migrations, Affinity portal customization, PDP toggles that default the right way. Built to hold up at 10K+ subscribers.
Middleware where Shopify stops and your business starts.
Cloudflare Workers, Pipedream, custom Remix apps. The integrations your ops team needs without bloating the storefront.
The proof.
$1M+/month wellness brand
Migrated a heavy legacy theme to Online Store 2.0 with a modern build system. Removed 280KB of jQuery and legacy tooling. Cut LCP by 1.8s.
Engineering led by Sergio Herrera as Lead E-commerce Developer.
Mid-market DTC
Audited a Recharge program approaching 10K subscribers and migrated to Skio with zero subscriber loss. Rebuilt the PDP subscription widget and Affinity portal customizations.
Engineering led by Sergio Herrera under contractor agreement.
Bilingual retail brand
Custom Cloudflare Worker handling product sync between an internal ERP and Shopify, replacing a flaky third-party connector.
Engineering led by Sergio Herrera under contractor agreement.
Three ways
to engage.
We scope before we sign. Pricing is fixed-fee or retainer — never hourly.
Audit
One-time technical and CRO audit of an existing store. Written report with prioritized findings, code-level specifics, recommended roadmap.
Project
Fixed-scope engineering — theme builds, migrations, Functions, middleware. Scoped before contract. Weekly check-ins. Most engagements live here.
Retainer
Ongoing engineering capacity for established brands. Roadmap-driven, not ticket-driven. Quarterly priority planning.
Tell us what's broken.
Or what's working but underperforming. Or what your last dev said couldn't be done. The first reply comes from Sergio.