Nexity: How to Migrate From a Legacy Stack to Next.js + Sanity — Fast, Safe, and Without Freezing Your Team
What Is Nexity?
Nexity is Pagepro’s proprietary system for migrating websites from legacy stacks to Next.js and Sanity. It is two things simultaneously, and the distinction matters for understanding why it works where other approaches fail.
A starter kit built from real migrations, not demo projects
Nexity is a production-grade Next.js + Sanity foundation built and refined across 20+ real client migrations. Every pattern in it came from a live client project.
None of it was designed in the abstract or optimised for a demo — it was built to solve the problems that show up on real migrations, with real content, real traffic, and real deadlines.
What that means in practice is that Nexity ships with the decisions already made.
Folder structure, TypeScript configuration, CMS integration, SEO layer — the things that consume the first two to three weeks of any Next.js project from scratch are pre-built, pre-validated, and ready from day one.
A 4-week migration service built on top of that foundation
The starter kit is the foundation. The service is how Pagepro delivers it.
Pagepro offers a fixed-price, 4-week migration engagement built entirely on Nexity. The scope and price are confirmed before any code is written. The engagement ends with a production-ready foundation — all content migrated, core journeys working, editors trained, and a Sprint 2 scope delivered for whatever custom integrations come next.
The starter kit gives developers a system they can trust. The service gives decision-makers a process they can sell internally — fixed cost, fixed timeline, zero ambiguity about what gets delivered.
Interested in trying nexity in your project?
What makes Nexity different from every other Next.js starter
Every Next.js starter available today was built for teams starting from zero. They are greenfield-first by design.
Nexity is the only production-grade starter built specifically for teams that already have something and need to move it without breaking what’s already working.
That difference shows up in what Nexity includes that no comparable starter does:
- redirect management built into Sanity Studio,
- a structured migration methodology,
- and architectural defaults validated on real client projects by a team that maintains Nexity on every engagement they deliver.
| Feature | Building from scratch | Generic Next.js starter | Sanity’s own templates | Nexity |
| Production-grade architecture | Depends on team | Partial | ❌ | ✅ |
| Sanity CMS integration | Manual wiring | ❌ | ✅ | ✅ |
| Built for migration | ❌ | ❌ | ❌ | ✅ |
| Redirect management in CMS | ❌ | ❌ | Partial | ✅ |
| SEO layer out of the box | ❌ | ❌ | Partial | ✅ |
| Validated on real client projects | ❌ | ❌ | ❌ | ✅ |
| Fixed-price migration service | ❌ | ❌ | ❌ | ✅ |
The patterns aren’t theoretical. They’re the ones that worked across 20+ live client projects — and Pagepro maintains Nexity actively because they build on it every day.
What’s Inside Nexity
Most migration conversations focus on the process — timelines, risk, cost. What rarely gets discussed is the substance of what a team is actually getting. This section covers exactly that.
Core architecture
Nexity is built on a pnpm workspace monorepo with two workspaces: /apps/web for the Next.js frontend and /apps/studio for Sanity Studio.
This structure is pre-configured and consistent across every Pagepro project — which means any developer who has worked on one Nexity project can navigate another without an onboarding period.
The language layer is TypeScript strict mode throughout, with Sanity TypeGen active from day one.
Sanity TypeGen automatically generates TypeScript types directly from Sanity schemas — so when a content model changes during the migration, the type definitions update automatically. An entire class of type-mismatch bugs is removed before they can happen.
The rest of the developer tooling is pre-configured and enforced from the first commit:
- ESLint + Prettier — code style enforced, not debated
- Husky + lint-staged — linting and type-checking run before every commit, keeping the codebase clean without relying on CI
- Dependabot — dependency updates handled automatically, keeping the codebase visibly maintained
Sanity integration — production-grade, not template-level
Nexity’s Sanity integration goes significantly deeper than anything available in Sanity’s own templates or community starters. What’s included out of the box:
- Sanity Studio v5 embedded directly in the monorepo
- GROQ query patterns — a library of pre-built queries covering the most common content retrieval patterns
- Portable Text renderer — production-ready rich text rendering with full block customisation
- Draft mode and live preview — editors see changes in real time before publishing
- Presentation Tool — visual editing directly on the frontend
- AI content features — auto alt-text generation, SEO meta description generation from content, content summarisation for excerpts
- Sanity TypeGen — TypeScript types auto-generated from Sanity schemas, kept in sync automatically
For teams evaluating Sanity + Next.js, this integration alone represents months of work that Nexity delivers on day one.
Claude Code agents — consistency at migration speed
One of the less visible advantages Nexity brings to a migration is how Pagepro’s team works inside it. Across recent migrations, Pagepro has built a library of Claude Code skills, agents, and commands — purpose-built for Nexity’s conventions and content model patterns.
In practice this means: when a developer needs to scaffold a new page type, wire a new Sanity schema, or implement a recurring pattern, they’re not doing it from memory or re-reading documentation. They run a command.
The output is consistent with every other instance of that pattern across the codebase — same structure, same types, same conventions.
The result is a migration that moves faster and produces a codebase that’s more consistent than what most teams achieve even on greenfield projects. It’s not a feature of the starter kit itself — it’s a capability Pagepro brings to every engagement built on Nexity.
SEO and performance layer
Nexity focuses on static page generation with revalidation as its primary rendering approach — keeping compute costs low while ensuring content stays fresh. There is no per-route configuration required, no risk of accidentally shipping a client-rendered page that search engines can’t index. Full HTML is available to crawlers on the first request, from the first deployed route.
The SEO layer covers:
- Next.js metadata API mapped to Sanity fields on every document type — pages, articles, case studies, site settings
- OG image generation — dynamic, per-page
- Sitemap.xml — auto-generated
- robots.txt — included and configurable
- JSON-LD structured data templates — covering the schema types most relevant to SMB content sites
- Canonical URL handling — built in, not retrofitted
Performance defaults are active from the first deployed route: next/image for automatic image optimisation, next/font for zero CLS on web font loading,
Vercel edge caching, and minimal client-side JavaScript to reduce main thread work. The target is 95+ Lighthouse Mobile as a baseline, with 100/100 as the delivery standard.
Redirect management deserves specific mention because it is the feature that matters most during a migration and that most starters don’t include. Nexity ships with a Redirects document type inside Sanity Studio.
Editors and project managers map old URLs to new ones directly in the CMS — no developer involvement, no spreadsheets, no Vercel configuration.
Every redirect is stored, versioned, and deployed as a 301. Redirect management becomes part of the content migration workflow, not an afterthought handled the week before launch.
The Migration System — How It Works in Practice
Nexity is the foundation. The migration system is what gets it delivered predictably, without disrupting the client’s product team or leaving SEO debt behind.
Here is the exact sequence Pagepro follows on every engagement.
The 48-hour demo
Before any scope is agreed or any contract is signed, Pagepro rebuilds a section of the prospect’s site using Nexity — with their real content, on the real stack — and delivers it in 48 hours.
No pitch deck. No proposal. Just working code.
This is deliberate. The fastest way to evaluate a migration is not to read about one. It’s to see your own site running on the new stack before you’ve committed to anything.
The demo answers the questions that no proposal can: what will the editor experience actually feel like, what will the performance look like, what will the content model look like for our specific content types.
The 4-week engagement
Once the demo is approved and scope is confirmed, the engagement runs on a fixed four-week timeline with defined deliverables at each stage.
| Week | Name | What gets delivered |
| Week 1 | Discovery & Demo | Full content and URL audit. SEO risk report. Redirect map started. Fixed scope and price confirmed. |
| Week 2 | Content Migration | All content and media moved to Sanity. Content schemas designed. 301 redirect map completed. |
| Week 3 | Core Build | Core pages and main user journeys built on Nexity components. Staging environment live. |
| Week 4 | Stabilise & Handover | QA, 95+ Lighthouse verified, redirect testing, editor training, Sprint 2 scope and estimate delivered. |
What “4 weeks” honestly means: a production-ready foundation — all content migrated, core journeys working, editors trained and unblocked.
Custom integrations and advanced features are scoped in Sprint 2 at handover. This is not a promise of a finished product. It is a promise of a solid, shippable foundation that the team can build on immediately.
What the migration team is actually doing while the product team ships
The question every CTO asks before approving a migration: what happens to our roadmap while this is going on?
The short answer: nothing. The product team keeps shipping.
Here’s what that looks like across the four weeks:
While the product team ships features → the migration team is auditing URLs, mapping redirects, and designing content schemas in Sanity. No overlap. No dependency.
While the product team closes sprint tickets → the migration team is moving content and media into Sanity Studio, validating the content model against real editorial workflows. The editors are already working in the new CMS. The product team doesn’t notice.
While the product team reviews PRs → the migration team is building core pages and user journeys on Nexity components. The staging environment is live. QA has already started.
While the product team plans the next quarter → the migration team is running Lighthouse validation, testing every redirect, training editors, and handing over a Sprint 2 scope for whatever comes next.
The reason this works isn’t clever project management. It’s that Nexity’s foundation is pre-built — the migration team doesn’t spend weeks on infrastructure decisions before touching the product. They’re productive from day one, which means the workstream moves fast enough to never become a bottleneck.
At the end of four weeks, the product team inherits a production-ready foundation. They didn’t slow down to get there.
Why Migrations Usually Fail — and How Nexity Is Built to Prevent It
Most migrations fail for reasons that are entirely predictable. The mistakes that cost teams their rankings or freeze their roadmap are not bad luck — they are the product of starting without a system designed to prevent them.
The SEO mistakes that cost teams their rankings
The teams that lose rankings during a migration are rarely the ones that ignored SEO entirely. They are the ones that addressed it too late — after the cutover, after the first crawl report, after the damage was already in motion.
The four failure patterns that appear repeatedly — and how Nexity addresses each one before it can happen:
| Mistake | What goes wrong | How Nexity prevents it |
| Missing redirects | URL structures change, old URLs go unmapped, years of accumulated link equity disappear overnight | Redirects document type in Sanity Studio — editors manage 301s throughout the migration, not the week before launch |
| Client-side rendering | Googlebot receives an empty HTML shell, content isn’t immediately indexable, rankings move before the team notices | Every page SSR or statically generated by default — no configuration step, no per-route decision, no risk |
| Metadata loss | Meta titles, descriptions, OG tags, and canonical URLs from the old CMS have no equivalent in the new content model — discovered three months after launch | Sanity fields mapped to Next.js metadata API on every document type from day one — nothing to re-implement |
| Core Web Vitals regression | New frontend scores significantly worse than the legacy site it replaced, triggering ranking adjustments within weeks | next/image, next/font, Vercel edge caching, minimal client-side JS — 95+ Lighthouse Mobile baseline from the first deployed route |
For most clients, the legacy site scores in the 40–60 range on Lighthouse Mobile.
A Nexity migration doesn’t just protect Core Web Vitals — it produces a measurable improvement that Google’s ranking systems respond to within weeks of launch.
Across 20+ migrations delivered on these patterns, Pagepro has recorded zero SEO ranking drops post-launch.
The development mistakes that freeze roadmaps
The SEO risk gets most of the attention in migration conversations. The development risk is quieter — but for most product teams, it’s the one that actually kills the project before it starts.
| Mistake | What goes wrong | How Nexity prevents it |
| The setup tax | Every Next.js project from scratch starts with 2–3 weeks of infrastructure decisions — folder structure, TypeScript config, CMS integration, CI/CD — before the team can touch a single product requirement | Nexity’s foundation is pre-built. The migration team is productive from day one. No infrastructure phase, no delay before product work begins |
| Architectural inconsistency | Without established patterns, every developer makes independent decisions. Code reviews take longer, onboarding takes longer, QA surfaces more inconsistencies | ESLint, Prettier, Husky, TypeScript strict mode enforced from the first commit — codebase stays consistent regardless of team size or when engineers join |
| No migration-specific tooling | Generic starters have no concept of a migration — no redirect management, no content audit process, no structured way to move content from one CMS to another | Redirect management, Sanity document types, and the 4-week engagement model all exist because migration is Nexity’s primary use case, not an afterthought |
| Stakeholder friction | Content teams get blocked, editorial calendars slip, marketing asks uncomfortable questions about timelines | Editors work in Sanity Studio from week two — familiar tooling, stable publishing workflow, unblocked throughout the entire migration |
The result of avoiding both sets of mistakes is what Pagepro’s track record reflects: development teams that kept shipping throughout, zero SEO ranking drops, and a foundation that’s production-ready on day one of go-live — not something to stabilise after the fact.
Who Nexity Is Built For
Nexity is not a general-purpose starter kit for anyone spinning up a new Next.js project.
It was designed for a specific situation: a team with a working site on a legacy stack that needs to move, but can’t afford to stop shipping while the move happens. If that describes your situation, Nexity was built for you. If it doesn’t, there are simpler tools that will serve you better.
Small and medium sized businesses on legacy stacks
Common entry points:
WordPress sites that have outgrown the platform. Slow build times, plugin conflicts, editorial workflows that don’t match how the content team actually works. The site is live and ranking — but every new feature costs more than it should and the platform is becoming the bottleneck.
Gatsby sites carrying performance debt. Built before the React Server Components era, these sites now require incremental fixes that never fully resolve the underlying architecture. The team knows a proper migration is inevitable; they’ve been putting it off because the last one was painful.
Custom PHP or Drupal stacks. The original developers are gone. The codebase is fragile. Documentation is sparse. Every new feature requires archaeology before anyone can touch it, and the cost of maintenance keeps rising while the cost of migration feels too high to justify.
What these teams share is a site with real traffic, real rankings, and a real product roadmap. They can’t afford a six-month freeze, and they can’t afford to lose the organic visibility they’ve spent years building.
Want to know more about Nexity?
Teams evaluating or already on Sanity
Nexity is opinionated about its CMS. For teams that have evaluated Sanity and decided it’s the right fit — or that are already on it — Nexity is the fastest path to a production-grade implementation.
The Sanity integration covers visual editing, live preview, the Presentation Tool, AI content features, TypeGen, and a full GROQ query pattern library. Building this from scratch takes months. Nexity delivers it on day one.
For teams evaluating a Sanity + Next.js stack as part of their migration target, Nexity removes the biggest risk in that evaluation: the gap between “Sanity looks good in the demo” and “Sanity works in production at our scale.”
What Nexity is not the right fit for
| Not a good fit | Why |
| E-commerce projects | Nexity is built for content-heavy platforms; dedicated e-commerce architectures have different requirements that Nexity wasn’t designed to handle |
| Enterprise teams with 100k+ page sites | Nexity targets SMB scale; large enterprise migrations have different scope, governance, and compliance requirements |
| Teams that need a finished product in four weeks | Nexity delivers a production-ready foundation; custom integrations and advanced features are scoped in Sprint 2 at handover |
Nexity vs. Building From Scratch
Building from scratch looks like the cheaper option on paper. No agency fee, no fixed-price engagement — just your internal team doing the work on a stack they control. The real cost calculation looks different once you account for what starting from scratch actually requires, and what it typically gets wrong.
The more useful frame isn’t agency vs. internal. It’s: do you want to start with three years of validated decisions, or start with none?
What building from scratch actually costs
The hours are only part of the picture. The deeper cost comes from three sources that don’t show up in the initial estimate:
Architecture time. Every decision Nexity has already made — folder structure, CMS integration, SEO layer, redirect management, TypeScript configuration, CI/CD — has to be made from scratch.
For a senior engineer, that’s two to three weeks of research, debate, and iteration before a line of product code is written. On a migration, where the team is already split between the legacy site and the new build, that delay compounds.
SEO recovery time. When rankings drop post-migration — and they frequently do without a structured approach — recovery takes months.
The cost isn’t just the lost traffic. It’s the engineering and SEO consultant time spent diagnosing and fixing problems that a structured approach would have prevented. That cost rarely appears in the original migration estimate and always appears in the post-mortem.
Delivery drag. Without established patterns, every developer on the project makes independent decisions.
Code reviews take longer. Onboarding new engineers takes longer. QA surfaces more inconsistencies at the end. The project finishes later than planned and with more technical debt than intended.
The comparison
| Factor | Building from scratch | Nexity migration |
| Time to first live route | Weeks to months | Days |
| SEO risk level | High | Low |
| Dev velocity disruption | High | Minimal |
| Core Web Vitals outcome | Variable | 95+ Lighthouse Mobile baseline |
| Redirect management | Manual / frequently missed | Built into Sanity Studio |
| Sanity CMS integration | Manual wiring from scratch | Pre-built, production-grade |
| Metadata continuity | Depends on implementation | Structured from day one |
| Ongoing maintenance burden | High — inconsistent patterns | Low — shared conventions |
| Engineering setup time | Full cost absorbed by team | ~70% reduction vs. scratch |
The cost that compounds
A missed redirect or a metadata gap doesn’t show up in a sprint retrospective. It shows up three months later in Search Console, after Google has already re-evaluated the affected pages and adjusted their rankings. By that point the engineering team that caused the problem has moved on, the context is gone, and recovery requires starting the diagnostic process from scratch.
The teams that choose Nexity over building from scratch are typically not doing so because they can’t build a migration themselves. They’re doing it because they’ve done the calculation: the cost of getting the migration wrong — in lost organic traffic, in engineering time, in delayed product work — exceeds the cost of doing it right from the start.
Nexity is Pagepro’s proprietary system for migrating websites from legacy stacks to Next.js and Sanity. It is two things simultaneously: a production-grade starter kit built and refined across 20+ real client migrations, and a 4-week fixed-price migration engagement that takes teams from their current stack to a modern, maintainable foundation without ranking drops or sprint disruption.
Yes. Nexity was designed with migration as the primary use case — the redirect management, the content audit tooling, and the 4-week engagement model all exist to solve migration-specific problems. That said, nothing prevents a team from using it as the foundation for a greenfield Next.js + Sanity project. Teams starting from zero will benefit from the architecture and the conventions, but they won’t need everything Nexity includes.
Before any scope is agreed or contract signed, Pagepro takes a section of the prospect’s current site, rebuilds it on the Nexity stack using their real content, and delivers working code in 48 hours. No pitch deck, no proposal — just the prospect’s own site running on the new stack. The demo answers the questions no proposal can: what the editor experience feels like, what the performance looks like, what the content model looks like for their specific content types. It is Pagepro’s primary sales mechanism because it removes uncertainty before any commitment is made.
A standard Nexity migration engagement runs four weeks from kick-off to handover. Week one covers discovery, content audit, and redirect mapping. Week two moves all content and media to Sanity and completes the redirect map. Week three builds core pages and main user journeys on Nexity components, with a staging environment live. Week four covers QA, Lighthouse validation, editor training, and handover — including a Sprint 2 scope and estimate for custom integrations and advanced features.
Yes. The migration runs as a separate workstream with no dependency on the product team’s sprint cadence. The reason this works is speed: because Nexity’s foundation is pre-built, the migration team is productive from day one and moves fast enough that it never becomes a bottleneck. The product team ships what they need to ship. The migration runs alongside them. At the end of four weeks, they inherit a production-ready foundation without having slowed down to get there.
Nexity is built specifically for Sanity. The integration covers Sanity Studio v5 embedded in the monorepo, GROQ query patterns, Portable Text rendering, draft mode, live preview, the Presentation Tool, AI content features, and Sanity TypeGen for auto-generated TypeScript types from Sanity schemas. For teams already on Sanity, or that have chosen it as part of their migration target, Nexity delivers a production-grade integration that would otherwise take months to build from scratch.
At handover, Pagepro delivers a Sprint 2 scope and estimate covering the custom integrations and advanced features that sit outside the fixed-price engagement. From that point, teams can continue with Pagepro on a monthly retainer for ongoing development, or take the foundation and build independently. The codebase is built on conventions that any Next.js developer can navigate without an extended onboarding period.
Conclusion
Nexity exists because migrations kept failing in the same predictable ways — and because Pagepro had delivered enough of them to know exactly why.
The ranking drops, the frozen roadmaps, the six-month rebuilds that still didn’t ship on time — none of that is inevitable. It is the product of starting a migration without a system built to prevent those outcomes.
Nexity is that system. Every pattern in it came from a real project. Every default was validated on a live migration. The 20+ engagements that shaped it are the reason the track record looks the way it does: zero SEO ranking drops, development teams that kept shipping throughout, production-ready foundations delivered in four weeks.
The choice between velocity and SEO protection during a migration is a false one. Nexity was built on the premise that both are achievable simultaneously — and the track record backs it up.
Ready to see it in practice?
The best way to evaluate Nexity is not to read about it. It’s to see your own site rebuilt on it.
Pagepro’s starting point is always the 48-hour demo: a section of your current site, rebuilt on the Nexity stack using your real content, delivered before any scope is agreed or any contract is signed. No pitch deck. No proposal. Just working code.
If you’re evaluating a migration and want to see what zero ranking drops and no sprint disruption actually looks like, get in touch with the Pagepro team.
