SUNSHINE — Luxury Spa & Massage
High-conversion 4-language Jamstack web platform with headless Sanity CMS and 100/100 Core Web Vitals.
01. Context & Objectives
SUNSHINE is a premier luxury massage and wellness studio based in Belgrade. The platform was engineered as an ultra-fast, 4-language Jamstack web application optimized for maximum conversion, sub-second load times (100/100 Core Web Vitals), and dominant local SEO rankings. It features 119+ statically pre-rendered pages, an interactive 'Treatment Finder' recommendation quiz, dynamic duration-based pricing calculators, and a self-service Sanity CMS Studio directly embedded at /studio.
The Engineering Challenge
Traditional spa websites suffer from sluggish WordPress templates, confusing pricing tables, lack of multilingual accessibility for foreign diplomats and tourists in Belgrade, and reliance on manual developer intervention for every single price or service tweak.
The Implemented Solution
Architected a cutting-edge Jamstack application with Next.js 15 App Router, React 19, and Tailwind CSS v4. Integrated next-intl v4 across 4 languages with subpath routing and full Schema.org JSON-LD structured data. Deployed Sanity CMS v3 with an embedded Studio on /studio so the salon team can manage treatments, pricing, and blog content independently, while Next.js Server Actions and Resend handle instant lead delivery without external backend servers.
System Architecture & Infrastructure
Frontend Layer
Next.js 15 (App Router with React Server Components), React 19, TypeScript 5.7+, Tailwind CSS v4, Framer Motion 12, Lucide React.
Backend & Serverless Handlers
Next.js Server Actions ('use server') with robust server-side schema validation and anti-spam protection.
Database & Relational Model
Sanity Headless CMS v3 with GROQ content schemas, PortableText rich text rendering, and embedded Sanity Studio (/studio).
Cloud Storage & Media Pipeline
Cloud-hosted asset pipeline with automatic next/image conversion to Next-gen AVIF and WebP formats.
Engineered Product Features
119+ SSG Pre-Rendered Pages
Statically pre-rendered routes via generateStaticParams ensuring instantaneous page navigation and zero server load.
Quad-Language i18n Architecture
Complete localization across Serbian, English, Russian, and Turkish via next-intl v4 with localized routes and dynamic hreflang tags.
Interactive 'Treatment Finder' Quiz
Custom client-side diagnostic component matching user goals (stress relief, back pain, sports recovery) to ideal therapeutic sessions.
Dynamic Duration-Based Pricing
Interactive category filtering and on-the-fly price computation across 30, 60, 90, and 120-minute session intervals.
Embedded Sanity Studio CMS
Native /studio dashboard enabling the client to autonomously update services, pricing tiers, and publish multilingual blog posts.
Exhaustive Schema.org JSON-LD SEO
Rich structured data for LocalBusiness/DaySpa, Service catalog, FAQPage, Article, and BreadcrumbList for top Google SERP visibility.
Engineering Challenges & Tradeoffs
Scalable Multi-Locale Static Generation with Headless CMS
Sub-Second LCP & Zero CLS on High-Resolution Visual Assets
Production Results & Reliability
Achieved 100/100 Core Web Vitals & Lighthouse score across mobile and desktop devices.
119+ statically generated routes serving zero-latency content across 4 languages (SR, EN, RU, TR).
Eliminated developer maintenance overhead by empowering the salon to manage treatments, prices, and articles via Sanity Studio.
Automated client booking inquiries routed straight to the salon management in real-time via Resend API and Server Actions.