One engineer.
One St. Bernard.
No overhead.
MTB Labs is led by Sergio Herrera — a senior Shopify engineer who spent seven years inside DTC brands before going independent. The bet: most agencies are either devs who don't think about conversion, or CRO teams who can't ship code. There was room for a studio that did both.
The story
Sergio joined his first DTC brand in 2018 as a junior front-end dev. Within two years he was the Lead E-commerce Developer for a $1M+/month wellness brand on Shopify, owning the theme, the apps, the migrations, the late-night cart-broke-on-Black-Friday calls.
The pattern that emerged across a half-dozen brands he worked with directly or in contract: the engineering work was rarely the bottleneck. The bottleneck was that the engineering team and the CRO team didn't share a vocabulary. CRO would propose a test, dev would say "that'll take three weeks," CRO would shelve it, and the brand would lose another quarter to risk-averse delivery.
MTB Labs is that third lane. Senior engineering work — Functions, theme architecture, subscriptions, middleware — executed with the rigor of a CRO team. Every change instrumented before it goes live. Every theme handed off with the kind of clean code your next dev won't apologize for.
Four principles. No exceptions.
Scope before signing.
Every engagement starts with a written scope. We'd rather lose the project at proposal than discover it at week three.
Instrumented by default.
If a change can't be measured, we're not the right team for it. Performance budgets and event tracking ship with the work.
Clean handoff or no handoff.
Code your next dev can read. Documentation that survives the team that wrote it. We don't sell lock-in.
Fixed-fee or retainer. Never hourly.
Hourly billing rewards slow work. We scope, we estimate, we ship — and we eat the variance ourselves.
What we ship with.
Storefront: Online Store 2.0, Liquid, Vite, Alpine.js, TypeScript where it earns its place. Functions: JavaScript, Rust for performance-critical paths. Subscriptions: Recharge, Skio. Middleware: Cloudflare Workers, Pipedream, Remix. CRO: GA4, Shopify pixel, server-side events. We don't sell the stack as a feature — these are the tools that produce the cleanest result for the work.
We don't build on platforms we don't use ourselves. This site runs on Astro + Vite + Alpine.js + GSAP, deployed to Cloudflare Pages. That's not a coincidence.
Sergio & Mía.
The studio is one engineer and one St. Bernard. Sergio writes the code. Mía supervises from the couch and signs off on every shipped build.
The "approved by Mía" stamp on every project deliverable started as a joke and stuck because the joke was the brand. One human, one dog, no overhead. Pricing reflects that — there's no agency margin, no junior-to-senior arbitrage, no "we'll bring in a specialist for that phase." When a project needs more hands, we partner with named collaborators and bill that transparently.
About the stamp.
Every case study, audit report, and shipped build closes with the Mía stamp. It's a small thing. It also means a real person — not an account manager — looked at the work and put their name on it.
Sergio writes the code. Mía signs off.