Custom BigCommerce themes that drive revenue, not slow it down
Off-the-shelf themes limit your brand and your speed. A custom Stencil theme gives you control of every template and every checkout moment. You get a storefront built to convert.
Off Grid Knives · 280% revenue growth ($1M → $3.8M)
Average PageSpeed after Stencil optimization
Typical delivery timeline for custom themes
App Marketplace compatibility on all builds
Most theme projects fail before the first pixel ships
When design intent and development scope are blurred from the start, you get a theme that looks like a template and performs like one too.
Design-to-Stencil handoff with fidelity tracking
Each design decision maps to a Stencil component or template variable. Nothing is interpreted. Every detail is specified before code starts.
Performance-first Stencil builds
Only the scripts your store uses ship with your theme. Render-blocking assets are removed. Core Web Vitals targets are set before development begins.
Update-safe component architecture
Custom templates extend Cornerstone cleanly. Overrides are isolated. BigCommerce platform updates do not touch your custom layer.
Redesign without replatforming
Get a new visual identity and user experience. Keep your data, your integrations, and your commerce stack. No migration, no re-testing, no risk.
Design intent gets lost in handoff
Figma files go to a developer who builds what they can, not what was designed. Spacing, type, and micro-interactions disappear.
Off-the-shelf themes ship unused scripts
Marketplace themes load 40 to 80 KB of JavaScript your store never uses. Core Web Vitals suffer. Conversion rates follow.
Customization breaks on every update
Hacked-together overrides create debt. Every BigCommerce platform update risks breaking your checkout, navigation, or product detail page layout.
No separation between redesign and rebuild
Agencies scope redesigns as full platform migrations. You pay for replatforming work you do not need, and go live six months late.
How we build custom BigCommerce themes that last
Select any phase. See exactly what happens and how it protects your storefront.
Discovery and Brief
Brand, conversion goals, and scope
Wireframe and Design System
Tokens, layouts, and component library
Stencil Setup and Templates
Parent extension, page templates, config
Component Build
Product detail, listing, cart, checkout, content pages
Performance Quality Assurance
Core Web Vitals, device, and browser matrix
Deploy and Handoff
Stencil push, docs, and source transfer
Every theme starts with a brief, not a mood board
We map your conversion goals, brand rules, and technical limits first. No Figma frame opens until scope is locked. We build only the page templates you need.
Design tokens first. Pixel-perfect components second.
Color, type, spacing, and motion are defined as tokens before component design begins. This means your Stencil SCSS variables match Figma from day one.
Cornerstone extended, never hacked
We extend the Cornerstone parent theme using Stencil's official override system. Your custom templates sit in their own directory. Platform updates never conflict with your code.
Every page template built to spec
Product detail, category, cart, search, account, and content pages are built as atomic Stencil components. Each renders cleanly on mobile, tablet, and desktop with no layout shift.
No theme ships without passing Core Web Vitals
Lighthouse runs on every device breakpoint. Accessibility checks cover WCAG 2.1 AA. Browser matrix covers Chrome, Safari, Firefox, and Edge before any theme activates.
You own the source code from day one
Theme pushed to your store via Stencil CLI. Full source code, documentation, and a recorded handoff session. You leave with everything needed to maintain or extend independently.
What you get in every custom theme build
Custom Stencil builds, locked performance targets, and safe redesign paths. We scope three deliverables your team reviews before launch.
Built from Cornerstone, designed for your catalog
Every page template reflects your product category and shopping behavior. Product detail layouts vary for single-SKU, variant-heavy, and configurable products. Category pages adapt to your faceted navigation depth.
- Cornerstone parent extension with clean override directories
- Page Builder sections for your merchandising and content team
- Configurable theme settings panel for non-technical brand updates
Themes that score 90 or more before you see them
PageSpeed targets are set in the brief and verified in quality assurance. We remove render-blocking scripts, lazy-load below-fold images, and inline only critical CSS. Your Core Web Vitals improve with your theme, not after it.
- Render-blocking script audit and elimination before build
- Critical CSS inlined, non-critical deferred per Stencil best practice
- CLS-safe image placeholders prevent layout shift on listing page grids
Performance Score
New brand identity, same proven commerce engine
Your store data, integrations, and checkout flow stay exactly as they are. We replace only the theme layer. No data migration. No integration re-testing. No downtime risk from a full replatform project.
- Theme previewed on a draft before any live change
- Activation takes under 60 seconds with stencil push
- Instant rollback to previous theme if needed
Off Grid Knives: $1M to $3.8M on a custom theme build
Single-client case study on BigCommerce — not a portfolio average. Custom Stencil theme, performance tuning, Klaviyo, and owned-channel growth over three years.
Off Grid Knives · 280% revenue growth over 3 years
Off Grid Knives · revenue multiplied ($1M → $3.8M)
Off Grid Knives · paid ad spend (owned channels only)
A premium manufacturer of outdoor and camping knives in a category with strict paid advertising restrictions. Growth had to come from the product and the platform. Not ad spend.
The existing store setup limited performance, user experience, and order processing. Without paid ads, every visitor arriving organically had to convert. If they left, the brand stalled.
We built a custom BigCommerce store with UX research, Stencil performance work, and Klaviyo integration. Organic SEO and owned channels replaced every paid acquisition source.
$1M → $3.8M, 280% revenue growth, and 3.8x are from the Off Grid Knives engagement only — not typical or average client outcomes. See the canonical case study on the BigCommerce hub.
Our Stencil theme engine
Select any stage. See what runs, what we check, and what you receive. No black-box builds, no surprises at launch.
stencil init
Scaffold and parent connection
stencil start (local dev)
Hot-reload dev server
stencil push --draft
Staging preview on live store
Lighthouse and device matrix
Performance and accessibility sign-off
stencil push --activate
Live activation with instant rollback
Three things most theme agencies skip
Typical partners blur design intent and development scope. We separate them. Select each claim to see exactly how.
Most agencies build the theme first and optimize later. We set Core Web Vitals targets in the discovery brief. Every component is built for those scores from the first commit. Quality assurance does not start until the theme passes Lighthouse on mobile.
Most agencies build the theme first and optimize afterward. We set Largest Contentful Paint, Cumulative Layout Shift, and First Input Delay targets in the discovery brief, so every component is architected for those scores from the first commit. Quality assurance does not start until the theme passes Lighthouse on mobile.
Performance reviewed after user acceptance testing. Fixes in post.
Performance targets locked at kickoff. Every sprint reviewed against targets.
Theme activates with 90 or more Lighthouse, not 60 that you chase later.
Redesign and rebuild are separate services
Other agencies scope a visual refresh as a full rebuild. You end up paying for a replatforming project when you needed a new look. We scope redesigns at the theme layer, keep your data and integrations untouched, and activate in under a minute.
- Data migration risk
- Integration re-testing
- 6-plus month timelines
- No data migration
- Integrations stay live
- 6 to 10 week delivery
You receive code, docs, and a real handoff
Most agencies deploy your theme and send a Loom. We deliver full source code on a Git repository, theme documentation covering every custom template and variable, and a live recorded walkthrough session with your team. You are never dependent on us to make changes.
Git repository
Full source with commit history
Theme docs
Every template and variable documented
Recorded walkthrough
Live session for your team
BigCommerce theme development FAQ
Stencil is the official BigCommerce theming framework. It gives developers full control over templates, styles, and client-side logic without modifying platform core files. Custom Stencil themes allow you to design every page and component to brand specification while keeping full compatibility with BigCommerce updates and the App Marketplace.
Most custom BigCommerce theme projects run 6 to 12 weeks depending on scope. A Stencil customization of a parent theme takes 4 to 6 weeks. A fully bespoke build from wireframe requires 8 to 14 weeks. Timeline depends on the number of unique page templates, component complexity, and quality assurance scope.
Yes. Many projects start from Cornerstone or another Marketplace theme, then extend it with custom templates, overridden styles, and new components. We evaluate whether to extend or build from scratch based on your design goals, performance targets, and long-term roadmap.
Done correctly, a custom Stencil theme improves performance compared to off-the-shelf themes loaded with unused scripts. We audit render-blocking assets, optimize image pipelines, defer non-critical JavaScript, and structure CSS for minimal layout shift. Core Web Vitals targets are built into our quality assurance process before any theme ships.
After launch, your team receives full source code, documentation, and a handoff session. For ongoing optimization, A/B testing, or iterative component work, we offer a growth retainer that keeps your development capacity on-demand without re-scoping each time.
Which scope fits your store?
Scoped before work starts · line-by-line pricing · no commitment to receive a proposal
Theme customization
Brand a Cornerstone or Marketplace theme with custom styles, header, footer, and up to 3 template overrides.
Custom Stencil build
Full custom theme from wireframe to deploy. You get 6 to 8 page templates, a component library, a config panel, and quality assurance sign-off.ff.
Brand refresh
New visual identity applied through Stencil. Includes user experience research, wireframes, design system creation, and full build. No replatforming required.
