Invisible UX collapse.
At the worst moment.How checkout layout shifts kill CVR →
Checkout Layout Shift
CLS 0.31CLS 0
Checkout layout shift eliminatedShopify Conversion Engineering Service
Your Traffic Is Converting.
Just Not Enough of It.
We deliver technical Shopify conversion engineering that maps the exact friction points killing your checkout — layout shifts, conflicting scripts, broken mobile flows — and engineers them out permanently. Not A/B tests. Not button colors. Root-cause fixes tied to measurable CVR lift.
For Shopify Plus brands spending $30k–$200k/month on paid acquisition. Project-based. No retainer required to start.
+22%Avg. CVR lift per engagementmeasured over 60-day post-deployment window
9 daysFastest checkout fix deployed$40k/month recovered from abandoned carts
2.1% → 3.4%CVR before and afterHealth & Wellness Shopify Plus brand
21 daysAvg. time to full deploymentfrom audit delivery to production
The Problem
Your Shopify Conversion Problem
Is Technical. Not Creative.
Most agencies recommend new copy, new creative, or a redesign. We look at your checkout CLS score, your iOS Safari error logs, and your mobile funnel drop-off data. Here's what's actually stopping your buyers from converting — and why it requires engineering to fix, not marketing.
Silent failures.
Visible revenue loss.Why your checkout fails on iOS Safari →
Conflicting Checkout Scripts
24% completion39% completion
Checkout completion rate after script fixMobile traffic up.
Mobile revenue flat.Why your mobile CVR is half your desktop CVR →
Mobile Funnel Friction
1.1% mobile CVR2.4% mobile CVR
Mobile CVR after funnel rebuildEvery store we audit has at least two of these three problems simultaneously. They don't appear in your analytics as technical failures — they look like normal abandonment. Our Shopify conversion engineering process identifies and eliminates each one in a single engagement.
The Process
How Our Shopify Conversion Engineering
Works in 21 Days.
Five phases. Every one documented. Every change tied to a CVR measurement. No heatmap recommendations recycled from another client's audit. No generic UX checklists. Your funnel, your specific friction, fixed at the root.
- Days 1–3
Conversion Leak Audit
Before we touch a single line of code, we manually map every drop-off point in your funnel. We analyse heatmap data, review session recordings at checkout, run cross-browser tests (especially iOS Safari), and pull JavaScript error logs from your checkout flow. Every finding is quantified: which specific friction point is causing how many abandonments per month, translated into estimated lost revenue. You receive a written Conversion Leak Report within 72 hours.
Deliverable:Conversion Leak Report — every friction point mapped, quantified, and prioritised by revenue impact - Days 3–8
Checkout Layout Shift Elimination
We audit every CLS event in your checkout flow — the DOM elements that shift position as the page loads and cause buyers to tap the wrong thing at the critical moment. Payment selectors, trust badges, shipping calculators, upsell injections — each is tested across devices and browsers, fixed at the code level, and verified against a CLS target of 0. We document every change with before/after CLS measurements so you can see exactly what was stabilised.
Deliverable:Checkout CLS report with before/after measurements per element + browser verification - Days 5–12
Script Conflict Resolution
Every third-party app in your checkout is audited for conflict behaviour. We identify scripts that load out of sequence, scripts that compete for the same DOM nodes, and scripts that produce intermittent failures on specific browsers or devices. Conflicts are resolved through script deferral, load-order correction, or surgical removal of scripts that produce no measurable conversion benefit. Every resolution is tested across iOS Safari, Chrome mobile, and desktop.
Deliverable:Script conflict log — every conflict identified, resolution documented, browser test results - Days 8–17
Mobile Funnel Rebuild
We rebuild the mobile friction architecture of your store's conversion funnel — from product page to order confirmation. Tap targets are corrected to minimum 44px. Variant selectors are rebuilt for thumb navigation. Sticky add-to-cart behaviour is implemented where CVR data supports it. Quantity selectors are fixed for one-handed use. The goal is a mobile funnel where every interaction that matters is frictionless on a 375px viewport with one thumb.
Deliverable:Mobile funnel rebuild with device-tested before/after CVR baseline comparison - Days 17–21
A/B Testing Infrastructure & Handoff
Once the structural friction is removed, we set up a statistically valid A/B testing infrastructure so you can continue optimising with confidence. This means a properly powered test framework — not the underpowered, multi-variable tests that produce misleading data. We document your post-engagement CVR baseline, define the testing velocity needed for statistical significance given your traffic, and hand off a testing roadmap for the next 90 days.
Deliverable:A/B testing framework setup + 90-day testing roadmap with sample size calculations
Every engagement starts with the free Conversion Leak Audit. No code is touched and no scope is agreed until you've seen exactly which friction points are costing you how much revenue. You decide what to fix — we never assume scope.
What's Included
Everything in the Shopify
Conversion Engineering Service.
No ambiguity. No upsells. Here's every deliverable you receive in a Webulux Shopify conversion engineering engagement — from the first friction audit to 30 days post-deployment.
Audit & Friction Mapping
- Manual checkout flow audit — every drop-off point identified across devices
- iOS Safari-specific testing — the browser responsible for most hidden checkout failures
- JavaScript error log analysis — every silent script failure in your checkout documented
- Heatmap and session recording analysis on checkout pages
- CLS measurement on every checkout element across mobile and desktop
- Estimated revenue impact per friction point — delivered in 72 hours
Conversion Engineering
- Checkout layout shift elimination — CLS target of 0 on all checkout pages
- Script conflict identification and resolution across all third-party checkout apps
- Mobile funnel rebuild — tap targets, variant selectors, ATC, quantity selectors
- Payment UX optimisation — selector behaviour, error messaging, confirmation flow
- Sticky add-to-cart implementation where CVR data supports it
- Cross-browser checkout verification — iOS Safari, Chrome, Firefox, Samsung Internet
A/B Testing Infrastructure
- Statistically valid A/B testing framework setup — not underpowered multi-variable tests
- Sample size calculations based on your actual traffic volume
- 90-day testing roadmap with prioritised hypotheses
- Test result tracking setup with CVR baseline documentation
Reporting & Handoff
- Before/after CVR comparison — measured over 30-day post-deployment window
- Full friction resolution log — every change documented with CVR impact
- Checkout CLS before/after report with per-element measurements
- Post-engagement CVR baseline for ongoing A/B testing reference
- 30-day monitoring to confirm lift holds under real traffic conditions
We Fix the Friction. Or We Keep Working.
Our Conversion Engineering engagement has one outcome target: measurable CVR improvement tied to the specific friction points we identify in your audit. If we don't produce a measurable lift in the initial engagement, we continue working at no additional cost until we do. We've never had to invoke this — but the commitment is real.
Pricing: Project-Based. Scoped After Your Audit.
We don't publish fixed pricing because the scope depends on what we find in your store's friction audit. A store with one checkout CLS issue and a clean script stack takes less work than a store with three conflicting checkout scripts, a broken mobile funnel, and five years of accumulated app debt. Your free Conversion Leak Audit includes a cost estimate — before you commit to anything.
- Free Conversion Leak Audit before any investment
- Fixed-scope project — no open-ended billing
- Custom quote based on your specific friction findings
- No retainer required to start
Client OutcomesResults That Speak
Results That Speak
For Themselves.
★★★★★
"The speed optimization sprint was flawless. They removed over 800kb of dead ghost scripts from apps we had deleted years ago. Our LCP dropped from 4.8s to 1.2s and our bounce rate on mobile dropped overnight. We had no idea deleted apps were still loading JavaScript on every page."
Michael ChangSpeed Optimization
★★★★★
"We'd tried three different speed apps before Webulux. None of them touched what actually mattered. Webulux read our actual Liquid code, found five render-blocking scripts we didn't know existed, and removed them. Mobile CVR went up 31% within two weeks. No redesign. No new theme."
James WhitfieldSpeed Optimization
★★★★★
"Our store had been live for four years and we had installed — and deleted — at least 20 apps over that time. Webulux found 620kb of dead JavaScript still loading on every single page. After removal our LCP went from 5.1s to 1.4s. Revenue that month was up 107%. The math on this is brutal — we'd been losing money for years."
Priya NairSpeed Optimization
★★★★★
"I was skeptical that page speed was our problem — our ads were converting fine on desktop. Webulux showed me that 74% of our traffic was mobile and our mobile LCP was 4.1 seconds. After their Liquid refactor it dropped to 1.3 seconds. Mobile revenue went up 44% in 30 days. I wish I'd done this two years ago."
Sofia MendesSpeed Optimization
★★★★★
"We were spending $80k a month on paid acquisition and couldn't understand why ROAS kept declining. Webulux audited our store and found seven third-party scripts loading synchronously — blocking everything. After deferring four and removing three entirely, ROAS improved 28% in the first month without changing a single ad."
Imogen SinclairSpeed Optimization
★★★★★
"Our checkout was experiencing mysterious layout shifts that caused users to click the wrong payment method. Nobody could figure out why. Webulux traced it to a conflicting loyalty app script that had been injecting DOM elements after page load. Fixed in two days. Checkout completion rate went up 19% immediately."
Aisha OkonkwoSpeed Optimization
★★★★★
"What impressed me most was how specific they were. Every ghost script they found came with the exact file name, its payload size, and an estimate of how much revenue it was costing us per month. That's not something a speed tool gives you. That's an engineer reading your code. Our LCP dropped from 5.6s to 1.8s."
Rachel KimSpeed Optimization
★★★★★
"Our product pages were beautiful but slow. Webulux implemented WebP conversion with proper lazy loading and deferred three non-critical scripts to post-interaction. Above-the-fold load went from 3.9s to under 1.5s. Add-to-cart rate on mobile improved 22% — no design change, just faster infrastructure."
Daniel RussoSpeed Optimization
★★★★★
"I've worked with agencies that promise speed improvements and deliver a Lighthouse score. Webulux delivered a CrUX report — real Chrome user data from our actual visitors — showing LCP went from 4.4 seconds to 1.1 seconds. They also gave me a full change log of every file they modified. Complete transparency."
Gemma DaviesSpeed Optimization
★★★★★
"We had three developers tell us our store was 'already optimized.' Webulux came in and found nine ghost scripts, two render-blocking fonts, and a Liquid section that was re-rendering on every scroll event. After their sprint, mobile LCP went from 4.7s to 1.5s and our paid social ROAS improved within the first week of the faster store going live."
Leila AhmadiSpeed Optimization
Proof It Works
Shopify Conversion Engineering Results.
Real Stores. Real Numbers.
These CVR lifts came from fixing technical checkout friction — no redesign, no new ad creative, no copy changes. Every metric below is tied to a specific engineering intervention.
CVR
2.1%3.4%
Checkout CLS
0.310
Revenue recovered$40k/mo
Time to deploy9 days
Checkout Friction Mapping Saves $40k/mo in Abandoned Carts
An 8.4% add-to-cart rate with only 24% checkout completion — far below the 45–55% industry benchmark. The cause was invisible: a conflicting trust-badge script causing intermittent checkout failures on iOS Safari, affecting 61% of buyer traffic.
Friction Removed:
- Identified and removed conflicting trust-badge script (iOS Safari checkout failure)
- Resolved 4 layout shift events in checkout flow — CLS dropped from 0.31 to 0
- Rebuilt payment method selector to prevent intermittent render failure
$40k/moRevenue recovered from checkout
Read full case study →CVR lift+82%
Checkout CLS
4 events0 events
Revenue+80% in 2 months
Time to win1 week
Checkout Layout Shift Elimination Drives +82% CVR in 1 Week
Mobile CVR was 60% lower than desktop despite identical product and offer. The checkout was shifting — four separate layout shift events were causing buyers to tap incorrectly at the payment step. Fixed in 11 days.
Friction Removed:
- Eliminated 4 checkout layout shift events causing mis-taps at payment step
- Removed conflicting app scripts causing intermittent mobile checkout failures
- Rebuilt mobile checkout Liquid templates for CLS of 0
+82%CVR lift in the first week
Read full case study →The Difference
Why Our Shopify Conversion Engineering
Finds What Generic CRO Misses.
Most CRO agencies end with a heatmap and a list of copy suggestions. We end with fixed checkout code and a measured CVR lift. Here's exactly how our approach differs from every other option you're considering.
Right fit for this service:
- High add-to-cart rate but low checkout completion
- Mobile CVR significantly below desktop CVR
- Checkout abandonment above 65–70%
- iOS Safari users converting at a lower rate than Android
- Shopify Plus or $30k–$200k/month on paid acquisition
- Tried A/B testing with inconsistent or inconclusive results
- Recently installed or uninstalled checkout apps
Not the right fit:
- Store under 50,000 monthly visitors — insufficient A/B test traffic
- CVR problem is offer or creative, not funnel — low add-to-cart rate
- Looking for a visual redesign alongside conversion work
- Under $15k/month revenue — audit ROI won't justify engagement
Common Questions
Shopify Conversion Engineering:
Your Questions Answered.
Everything you need to know about our conversion engineering service before booking a call.
Shopify conversion engineering is the technical process of identifying and eliminating the specific friction points in your store's checkout funnel that cause high-intent buyers to abandon. At Webulux, this means manual friction mapping, checkout layout shift elimination, conflicting script resolution, and mobile funnel rebuilding — not heatmap recommendations or button colour tests. The difference from generic CRO is the diagnosis method: we start with JavaScript error logs, CLS measurements, and iOS Safari cross-browser testing, not with click data and hunches.
High Shopify checkout abandonment is almost always caused by technical friction, not design or copy. The most common causes are: layout shifts during checkout that cause accidental taps on the wrong elements, conflicting third-party scripts that cause intermittent failures on iOS Safari (affecting 40–60% of mobile buyer traffic), slow checkout load time that breaks purchase momentum, and payment selector bugs that appear on specific devices. These issues look like voluntary abandonment in your analytics — they're invisible without a code-level audit.
Most Webulux conversion engineering engagements are fully deployed within 14–21 days from audit delivery. The fastest wins — checkout layout shift fixes and conflicting script removal — often produce measurable CVR improvement within the first week of deployment. Our fastest case study recovered $40k/month in checkout revenue in 9 days. The full engagement — audit, checkout fixes, mobile funnel rebuild, and A/B testing infrastructure — runs across 21 days, followed by 30 days of post-deployment monitoring.
Our clients average a +22% CVR lift across all conversion engineering engagements, measured over a 60-day post-deployment window. Individual results depend on the severity of friction in your current funnel — stores with unresolved checkout layout shifts, conflicting iOS Safari scripts, or broken mobile flows tend to see larger lifts because there is more structural friction to remove. Your free Conversion Leak Audit includes a specific revenue impact estimate for your store before you commit to anything.
No. Every Webulux conversion engineering engagement produces measurable CVR improvement within your existing design. We work inside your current theme, checkout configuration, and app stack — fixing the technical root causes of drop-off without changing your visual presentation. Our case study clients achieved CVR lifts of +22–82% with zero visual changes to their stores. A redesign is only recommended when the visual architecture itself is the fundamental barrier — which is rare, and not where most stores' CVR problems actually live.
Checkout friction mapping is the process of identifying every technical and UX barrier that prevents a high-intent buyer from completing a purchase once they've reached checkout. At Webulux, this combines heatmap analysis at the checkout stage, session recording review of abandonment events, JavaScript error monitoring during checkout, cross-browser testing (especially iOS Safari vs Chrome), CLS measurement per checkout element, and funnel drop-off analysis tied to specific device/browser combinations. The output is a map of every friction point with an estimated monthly revenue cost per issue.
What is Shopify conversion engineering?
Why is my Shopify checkout abandonment rate so high?
How long does Shopify conversion engineering take?
What CVR improvement can I expect from Shopify conversion engineering?
Do I need to redesign my Shopify store to improve conversion rate?
What is checkout friction mapping?
Free for Qualifying Stores
Start With the Free Conversion Audit.
Commit to Nothing.
Every Webulux Shopify conversion engineering engagement starts with a free, manual Conversion Leak Audit. Our engineering team personally reviews your checkout flow — not a tool, not an automated scan. You'll know exactly which friction points are killing your CVR, which scripts are failing on iOS Safari, and what fixing each one is worth in recovered revenue — before you commit to anything.
- Checkout friction map — every drop-off point identified with estimated monthly revenue cost
- iOS Safari testing — the specific checkout failures killing your mobile buyer traffic
- CLS measurement per checkout element — which shifts are causing mis-taps and how much they cost
- Script conflict report — every third-party app creating checkout failures, named and documented
- Prioritised fix roadmap — ordered by revenue impact, not by technical complexity
Manual. Not automated. Our engineering team personally reviews every checkout flow. Limited to 5 audit requests per week to maintain quality.
Apply for Free Conversion Audit →Book a Discovery Call Instead →
5 audit slots per week. Response within 24 hours.