Case Study: Building a Headless WordPress + Next.js Site for a SaaS Startup
A B2B SaaS client came to us with a request: they needed a marketing site, but it had to integrate with their product API. They wanted to display live user testimonials, updated pricing (synced from their app), and real-time case study metrics.
A traditional WordPress site wouldn't cut it.
The brief:
- Marketing site (landing page, features, pricing, blog, case studies)
- Dynamic pricing (pulled from their API, updates daily)
- Live testimonials (synced from their customer database)
- Blog (SEO-critical)
- Integrate with their authentication (users can log in via the site)
Traditional solution: WordPress plugin + lots of custom code + performance hits.
Our solution: Headless WordPress + Next.js
WordPress as the CMS (blog, case studies, testimonials, static content).
Next.js frontend (pulls data from WordPress AND their SaaS API).
Deployment on Vercel (Next.js native, auto-scaling, performance optimised).
Why this stack?
WordPress is the best CMS for content-heavy sites. Blogs, case studies, media management — it's unbeatable.
But WordPress isn't great at real-time data or complex integrations.
Next.js let us:
- Build a blazing-fast frontend (9.2 Lighthouse score)
- Integrate their API seamlessly
- Use Next.js Image Optimisation (images load significantly faster)
- Use server-side rendering for SEO (critical for a marketing site)
- Use Incremental Static Regeneration (blog posts update instantly when published, no rebuilds needed)
The architecture:
WordPress (hosted on WP Engine) serves as the CMS.
Next.js API routes aggregate data: fetch blog posts from WordPress, pricing/testimonials from their SaaS API, combine and render.
When the client updates a blog post in WordPress, Next.js automatically regenerates that page. No manual rebuilds.
The results:
- Site loads in 0.9 seconds (vs. their old WordPress site at 3.2s)
- Dynamic pricing updates in real-time (no manual updates)
- Blog posts automatically appear on the site (client just writes in WordPress)
- 95+ Lighthouse score (desktop and mobile)
- Seamless API integration (users see live data)
The handoff:
Client maintains the WordPress site themselves. They add blog posts, case studies, testimonials in WordPress. Everything flows to the frontend automatically.
Our team maintains the Next.js frontend and API integrations. We update it quarterly.
Would we do it again?
Yes. This is the future of WordPress agency work. Clients want performant sites AND easy content management. Headless gives you both.