Available for new engagements

Paul Delcloy

Web Performance Architect · Independent consultant

My role: helping e-commerce brands and enterprise teams turn the performance of their site or app into a lever for user experience, brand image and revenue. Technical expertise built over 8 years, applied to business outcomes. CHANEL, RIMOWA and SiriusXM rely on this approach.

years of experience

clients supported

focused on performance

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About me

A single specialty, practised in depth for 8 years

I'm Paul Delcloy, an independent consultant specialised in web performance. For 8 years, my work has focused on a single goal: making websites measurably faster. Not a one-off bump on a synthetic Lighthouse score, but a real improvement for end users on their own devices, with a measurable impact on revenue.

I work with global enterprises and high-traffic e-commerce sites: CHANEL, RIMOWA, SiriusXM, Jimmy Fairly, April Moto, among others. These environments share one trait: performance is never an isolated problem. It results from a combination of front-end, back-end, third-party scripts, infrastructure and product decisions. My role is to identify precisely where time is lost, then to eliminate it.

My work doesn't stop at handing in a report. I act directly in the codebase, I implement the fixes, I measure the gains and I document the before/after.

Background

From agency to independent consulting

Before going independent, I co-managed Wapiti, a digital agency in Lille. For several years, I led the technical team (eleven people, from developers to project managers) and supported e-commerce merchants from zero to several million euros in annual revenue. That's where performance became the most effective lever to grow a merchant site.

Since 2022, I've been a full-time independent consultant focused on web performance. My engagements are long, embedded in client teams, and exclusively measured against field data outcomes (Google CrUX, real-user monitoring).

A few notable engagements

CHANEL

2022 → 2026

Web Performance Architect

Audits across all global markets (APAC, EMEA, AMER, CN, JP), embedded in internal technical teams.

SAP Hybris ReactJS Akamai Cloudinary Dynatrace SpeedCurve

Checkout reduced from 12 s to under 2 s
80 % of visits rated as fast on Google CrUX
TBT (Total Blocking Time) reduced by 40 %
TTFB reduced by 20 %

RIMOWA

2024 → present

Web Performance Consultant

Worldwide audits (APAC, EMEA, AMER, JP), performance roadmap, code reviews, delivery follow-up.

SFCC Akamai SpeedCurve

95 % of users with an excellent experience on CrUX
TTFB reduced by 46 %
Perfect CLS across the entire site
Performance budgets defined, technical and business impact tracked

SiriusXM

2025 → present

Web Performance Consultant

Audits on the web platform and marketing sites. Custom reporting through synthetic and real-user monitoring.

React.js Next.js Angular Akamai Datadog SpeedCurve

82 % of users with a good experience on CrUX
Continuous follow-up of the performance roadmap
Optimisations implemented hands-on inside the product codebase

Method

A three-stage method

Diagnose, optimise, monitor. Three complementary, inseparable stages.

Diagnose from real data

Core Web Vitals measured in the field through CrUX data, network waterfall and back-end profiling. Without reliable data, optimisation is done blind, and one spends three weeks on lazy loading while the real bottleneck sits in a 1.2-second TTFB.

✓ Full audit: LCP, INP, CLS, TTFB
✓ Network waterfall and critical path
✓ Action plan prioritised by business impact

your-site.com

Overall score

Core Web Vitals

LCP —

INP —

CLS —

Issues detected

Optimization Checklist

Actions identified during the audit

0/17

applied

Image optimization Images

JS bundle reduction JS

Server compression Server

Cache strategy Server

Font optimization Fonts

Split product page CSS into pdp.css CSS

+12 more optimizations

Implement in the codebase

My work doesn't stop at a PDF report. I implement the fixes directly, across every layer: front-end, back-end and infrastructure. Each action is measured before/after to prove the gain.

✓ Optimising images, fonts, JS and CSS
✓ Refactoring expensive SQL queries
✓ Cache and CDN strategy

Monitor to prevent regressions

An optimisation lost three sprints later is a wasted investment. I set up the monitoring that catches post-deployment regressions before your users do, and before Google does.

✓ CrUX and lab dashboards
✓ Threshold alerts on business metrics
✓ Performance budget enforced in CI/CD

⏱️ ↓

0 ms

TTFB

🖼️ ↓

0 s

LCP

📐 ↓

CLS

🎯 ↑

0 /100

Score

Services

Three complementary modes of engagement

From a one-off diagnostic to long-term support.

Web performance audit

The full diagnostic that reveals where time is lost, and what it costs.

Optimisation

Hands-on implementation of fixes, directly in your codebase.

Monitoring

Continuous monitoring that catches regressions before your users do.

All my services The technologies I optimise

Testimonials

What the clients I've supported have to say

Excellent work.
Paul has significantly improved the site's speed and perfectly aligned it with Google's recommendations.
Professional, thorough, and efficient, I highly recommend.

Nicolas - April Moto

Digital & E-commerce Director

We are very satisfied with Paul's work. He is quick, available, and particularly effective. Since his arrival, very good results have been observed, both in terms of performance and responsiveness. A real asset for our team.

Léo - Luxury brand

E-commerce Product Owner

I don't know if we've said it enough.
But if you want to improve your loading speed,
Make Google happy and get your Core Web Vitals in the green,
Contact Paul Delcloy.

Florian Darroman - Les Makers

Co-founder

The blog

What I write

I document on a technical blog what I encounter on engagements: field-based case studies, recurring mistakes seen on dozens of sites, proven audit methods, tool comparisons. The goal: produce what you won't find in official documentation, source every claim, and prefer copy-pasteable code to prose.

Performance Outils

Google Lighthouse: complete guide to auditing your website

Master Google Lighthouse from A to Z: installation, key metrics, score interpretation, tool limits, and real-world web performance case studies.

Web Performance Outils

WebPageTest vs PageSpeed Insights: complete comparison

WebPageTest vs PageSpeed Insights: lab data vs field data, diagnostics vs SEO signal. Comparison, use cases, scripting, API and ecosystem.

E-commerce

Core Web Vitals for e-commerce: the mistakes that cost you sales

7 Core Web Vitals mistakes are dragging down your e-commerce site. Fix them to boost your SEO and conversions.

See all articles

FAQ

Working with me

The most common questions before a first conversation.

Is my site big enough to need a web performance consultant?

The earlier you address performance, the less it costs. Even on a small site, a short engagement lays clean foundations (a suitable CMS, decent hosting, build pipeline, controlled third-party scripts) and prevents the technical debt that piles up as the site grows. Optimising a 500-product catalogue is far cheaper than tearing it all down once it has reached 50,000, on a site grown heavy and patch-ridden. My engagements scale with the volume: a targeted audit for small teams, long-term support for growing or mature sites.

Why work with a web performance consultant or agency?

Web performance is a full discipline in its own right, requiring dedicated tools, precise methods and experience accumulated across diverse contexts (e-commerce, luxury, high traffic, internationalisation). An independent consultant or a web performance agency bring you the same value: expertise concentrated on a single subject, full-time, with the ability to measure the business impact of an optimisation on field data (Google CrUX, real-user monitoring, conversion). It's what an in-house senior developer can only provide part-time, constantly trading off against other priorities. The real question isn't "agency or consultant" but "performance handled by a specialist, or not at all".

Do you take one-off projects or only long engagements?

Both, and I'm open to new engagements at all times. A one-shot audit is valuable to frame a subject before a redesign, after a major release or to plan a quarter. Long engagements (several months to several years) suit sites where performance is a recurring battle: frequent deployments, large teams, third-party scripts constantly changing. The right format depends on your context, not mine.

How does your audit differ from a Lighthouse report?

Lighthouse measures a site in a lab: virtual machine, simulated connection, a single scenario. It's useful for preliminary diagnostics, never enough for a business decision. The gains that truly matter, in SEO and conversion, are measured on field data: Google CrUX and real-user monitoring (SpeedCurve, Datadog, Dynatrace). An audit that doesn't cross-reference the two misses the bottlenecks that actually cost money.

What if you don't find anything urgent to fix?

It can happen and the report says so plainly. No engagement is created artificially to bill. On most high-traffic e-commerce sites, however, there's always still room for gain: metrics evolve (INP replaced FID in 2024), stacks age, third-party scripts pile up. The real question isn't "is there something to fix" but "where to set the bar, at what cost, for what ROI".

A slow site costs you customers. Let's talk.

Independent consultant

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8+ years of experience

100% satisfied clients
Data 2023-2025