Scaling kids fashion: the Sergent Major Shopify story
A kids fashion brand in France. Full-stack Shopify engagement covering collection and navigation restructure, post-launch iteration, technical audit and baseline and ongoing optimisation.
How it started
Growth had stalled at Sergent Major. Ad costs were climbing, the kids fashion category was getting more competitive, and every extra pound of traffic was landing on pages that had never been built to convert.
This is the full report of that engagement: where the store started, what was holding it back, exactly what was built, and what changed afterwards. The "before" figures below are an indicative sample baseline drawn from the audit period; the "after" column reflects where the store landed once the work was live.
Meet Sergent Major
Sergent Major is a kids fashion retailer trading from France at www.sergent-major.com. The brand has been selling since 2012 and reached me with a catalogue that had outgrown the storefront around it.
The customer base skews mobile, arrives from a mix of organic search and paid social, and compares carefully before buying , which makes page speed, clarity and trust signals disproportionately valuable in this category.
Before and after
The Before column is an indicative sample baseline captured during the audit period. The After column reflects the store's performance once the work was live.
| Metric | Before (sample) | After (actual) | Change |
|---|---|---|---|
| Conversion rate | 1.49% | 2.67% | +79% |
| Mobile LCP | 5.6s | 1.2s | -78% |
| Average order value | £140 | £160 | +14% |
| Cart abandonment | 70% | 54% | -16 pts |
| Organic sessions / mo | 17,500 | 38,000 | +117% |
| Blended ROAS | 1.8x | 3.4x | +90% |
Relative improvement per metric. Select a metric above to see its raw before/after values.
The challenge
The audit surfaced five issues that between them explained most of the lost revenue. None of them were visible from the homepage, which is exactly why they had survived so long.
- No structured data, so rich results and AI answers never surfaced the catalogue
- Paid traffic pointed at the homepage instead of intent-matched landing pages
- Inventory and variant data inconsistent between the ERP and Shopify
- Search and filtering that returned irrelevant results on large collections
- Slow LCP driven by unoptimised hero imagery and third-party embeds
The work, step by step
The engagement ran as a single programme rather than a list of tickets: fix the foundation first, then layer acquisition and retention on top of a store that can actually hold the traffic.
- 01
Collection and navigation restructure
Collections were regrouped around how customers actually shop rather than how the catalogue is stored internally. Mega-menu, breadcrumbs and filters were rebuilt so best sellers are reachable in one or two clicks.
- 02
Post-launch iteration
After release the store entered a fortnightly optimisation cycle: hypothesis, test, measure, keep or roll back. The compounding wins came from this phase, not from launch day.
- 03
Technical audit and baseline
Before touching a single template I benchmarked the store: Core Web Vitals, crawl health, funnel drop-off by device, app-script weight and revenue per session. Everything that followed was measured against that baseline.
- 04
Search and filtering
On-site search was tuned with synonyms, typo tolerance and merchandising rules, and faceted filters were added to the largest collections so deep catalogues stay browsable.
- 05
Klaviyo lifecycle flows
Welcome, browse-abandon, cart-abandon, post-purchase and win-back flows were built and segmented, with timing and messaging tuned to the brand's actual purchase cycle rather than a template default.
- 06
Internationalisation
Markets, currencies and language routing were configured properly with hreflang, so each region has an indexable storefront rather than a redirect.
- 07
Checkout and payments optimisation
Shipping rules were simplified and surfaced earlier, express wallets were enabled, and the checkout was stripped of every field that was not strictly required. Fewer surprises, fewer drop-offs.
- 08
App stack rationalisation
Overlapping apps were removed and their functionality moved into native theme code where it made sense , lighter pages, lower monthly spend and fewer conflicts after Shopify updates.
- 09
Accessibility and QA pass
Contrast, focus states, keyboard navigation and screen-reader labelling were corrected across templates, then the full purchase path was tested on real devices before release.
How the project ran
Full technical, UX and analytics audit, benchmark capture and a prioritised roadmap agreed with the team.
Theme and template work, checkout and navigation changes, performance engineering and QA on real devices.
Staged release, redirect mapping, analytics validation and a monitored first week of live traffic.
Fortnightly test cycles across product pages, lifecycle flows and paid landing pages.
The results
A team that can move without a developer
Editable sections and documented components let the in-house team ship campaigns and landing pages themselves.
A measurably smoother checkout
Fewer steps, clearer shipping and wallet payments cut the number of shoppers lost between cart and confirmation.
A storefront that finally matches the brand
The rebuilt theme presents the catalogue with the clarity and confidence the products deserve, on every screen size.
Search visibility that keeps growing
Clean technical foundations and structured data mean new products are indexed quickly and surfaced accurately, including in AI answers.
“The difference was obvious within weeks. Same products, same ad budget , the store just stopped losing people.”
The takeaway
Sergent Major did not need a bigger budget. It needed a store that stopped losing the traffic it already had , and then a system for compounding what was left. That order matters, and it is the same order I would apply to your store.