Justin Cappelle
Your trusted B2B freelance developer
White-label web developer for agencies in Switzerland.
White-labelModern stackReplies within 48 hours
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What I bring to your client projects
You sell, I build. You keep the client relationship, I take care of the technical delivery. A smooth partnership that lets you scale without hiring.
01
Business and corporate websites
From one-page sites to multi-page corporate websites, I build custom sites that are fast and optimised for SEO. Next.js, WordPress, Webflow: I work with whichever stack you offer your clients.
Next.js / React
WordPress / Webflow
Built-in technical SEO
02
Mobile apps
I build cross-platform mobile apps with React Native. A single codebase for iOS and Android, native performance and a faster time to market for your clients.
React Native
iOS and Android
App Store / Play Store publishing
03
Web apps and SaaS platforms
From internal dashboards to complete SaaS platforms, I build solid web applications with authentication, payments, databases and APIs. Architecture designed to scale.
Full-stack TypeScript
Stripe / Auth / DB
Scalable architecture
04
Custom e-commerce
Shopify, WooCommerce, PrestaShop or headless: I build high-performing online shops with an optimised conversion funnel and business integrations (ERP, CRM, logistics).
Shopify / WooCommerce
Headless commerce
Business integrations
Why agencies trust me.
Since 2018, I've worked closely with web agencies, creative studios and marketing agencies. My role: turning your mock-ups and briefs into products that are delivered, tested and working.
01
Smooth integration into your processes
I'm not a freelancer you need to micro-manage. I plug into your tools (Figma, Slack, Notion, GitHub, Jira) and follow your coding conventions and workflows. You brief me, I deliver. Like a member of your team, without the fixed costs.
- Git, CI/CD, code reviews
- Direct, transparent communication
Your workflow, respected
Brief and access to your repo
specs, conventions, project board
Development on your stack
your tools, your coding standards
Pull request et code review
nothing is merged without approval
Delivery and deployment
tested, documented, in production
Tech stack
Next.js
React
TypeScript
React Native
Node.js
Tailwind
WordPress
Shopify
Webflow
7+
Years of experience
02
A broad, proven technical range
A WordPress business website for a tradesperson, a React Native app for a start-up, a full-stack SaaS platform for a major account: I adapt to the project, not the other way round. Every technology I offer, I've been running in production for years.
- Front end, back end, mobile
- From prototype to production deployment
03
Reliability and deadlines you can count on
When an agency hands a project to a freelancer, the biggest fear is being ghosted or left with delays. I've worked with agencies since 2018 precisely because I deliver on time, keep you updated throughout and never disappear mid-sprint.
- Guaranteed availability within 48h
- NDA and full confidentiality
Your agency
Technical partner
Projects delivered50+
Repeat collaboration rate100%
Average response time< 2h
Start a project
100% reliable
Since 2018
A freelancer who understands
how agencies work.
I know what it takes to deliver a client project on time with a tight budget. I know the pressure of deadlines, last-minute scope changes and demanding clients. That's why the agencies I work with keep coming back. I don't simply carry out tickets. I anticipate problems and propose solutions before they become critical.
Business and corporate websitesMobile appsWeb apps and SaaSE-commerceFully white-labelBroad tech stack
+20
5.0
100% satisfied clientsReal projects,
measurable results.
Every website is custom built around a real business need: it has to look good, earn trust and, above all, perform well enough to bring in results.
Au Koala Zen
A full redesign for Au Koala Zen, a gentle osteopathy and therapeutic massage practice in Penthalaz. New brand guidelines, a custom WordPress theme, on-page SEO rebuilt from scratch and a built-in blog.
WordPressCustom themeSEO
NORA Immobilier
A new website for NORA Immobilier, a close-knit property management firm in Nyon. Custom WordPress build, digital identity created with Immosprint and listings synced from the property CRM.
WordPressProperty CRMCustom build
FLAA architectes associés
A full redesign for FLAA, an architecture firm in Bussigny and Lausanne. Hand-coded WordPress theme, carefully crafted animations and projects shown at their best. Delivered in partnership with Immosprint.
WordPressCustom themeArchitecture
Régal'Animals
A full redesign of Régal'Animals, an online shop specialising in food for dogs, cats and ferrets. New WooCommerce store, restructured catalogue and a checkout built to convert.
WooCommerceWordPressE-commerce
Tell me about your project,I'll handle the rest.
Describe what you need in a few clicks. I'll get back to you within 24 hours with a personal analysis and a free quote.
5.0
30+ happy clientsAssociation Artémont
Concerts and cultural events
“Justin brought together creativity, responsiveness and technical expertise to build a website that lives up to our standards. He listened, he was flexible, and the result is flawless. We will be calling on him again for our next projects without a second thought.”
Nathanaël B.
Alpura Lodges
“A modern, smooth website that is completely true to our image. Justin listened at every stage, came up with relevant ideas and delivered work of exceptional quality, on schedule. A serious, creative and passionate developer.”
Joel Lopez
ImmoSprint
“Impeccable work of flawless quality. Justin designed a website that matches our vision exactly, while bringing his own technical and creative expertise. The result: a professional, modern and extremely fast website.”
Romain B.
Leedy
“Available, committed and attentive, Justin built a website that goes beyond what I expected. He took the time to understand my needs and delivered a beautiful result, on time. I highly recommend him to anyone looking for a real professional.”
Association Artémont
Concerts and cultural events
“Justin brought together creativity, responsiveness and technical expertise to build a website that lives up to our standards. He listened, he was flexible, and the result is flawless. We will be calling on him again for our next projects without a second thought.”
Nathanaël B.
Alpura Lodges
“A modern, smooth website that is completely true to our image. Justin listened at every stage, came up with relevant ideas and delivered work of exceptional quality, on schedule. A serious, creative and passionate developer.”
Joel Lopez
ImmoSprint
“Impeccable work of flawless quality. Justin designed a website that matches our vision exactly, while bringing his own technical and creative expertise. The result: a professional, modern and extremely fast website.”
Romain B.
Leedy
“Available, committed and attentive, Justin built a website that goes beyond what I expected. He took the time to understand my needs and delivered a beautiful result, on time. I highly recommend him to anyone looking for a real professional.”
Yann Wegmüller
Chantemerle
“Meticulous, reliable work with excellent value for money. Justin delivers exactly what he promises, on time and with no unpleasant surprises. A dependable, rigorous developer. I recommend him without any hesitation.”
Yann Chaplet
Trio De Turismo
“Justin built our website to perfection. He respected our wishes while bringing his professional touch and sound advice. The result goes beyond our expectations. Excellent service, I recommend him without the slightest hesitation.”
Reviews translated from French
Frequently asked questions about agency partnerships
Can't find what you're looking for? Get in touch directly, I always reply within 24 hours.
Get in touchI work entirely under your brand. Your clients never know I was involved. I adapt to your processes, your project management tools (Notion, Jira, Linear, Trello) and your communication channels (Slack, Teams). You keep full control of the client relationship.
I cover a broad technical range: Next.js, React, React Native, Node.js, TypeScript, WordPress, Shopify, Webflow, WooCommerce, PrestaShop. For SaaS and web app projects, I work with modern stacks (Vercel, Supabase, Firebase, Stripe). I can also adapt to your clients' existing stack if needed.
Absolutely. I'm used to picking up projects midway, auditing existing code and joining an established team. I take the time to understand the architecture before touching anything, so nothing breaks.
I always keep capacity in reserve for my partner agencies. I can generally start a project within 48 to 72 hours. For technical emergencies (critical bug, tight deadline), I respond the same day.
I offer day rates or fixed project prices, whichever you prefer. No surprises: a clear, detailed quote before every assignment. For ongoing partnerships, I offer preferential terms in exchange for guaranteed volume.
Technologies and specialities
The areas I know best for building custom websites, interfaces and apps.