How to Build a CMS Migration Roadmap From AEM to Sanity

Most AEM migrations stall not on the technology but on the fear of a big-bang cutover: a two-year reimplementation, a frozen content calendar, and an author team that has to relearn everything the week before a product launch. The classic failure mode is the "lift and shift that never ships," where a replatform runs so long that the new stack is already behind the DXP it was meant to replace, and the CFO starts asking why the license renewal keeps arriving anyway.

The reframe is that migration is not a single event; it is a governed sequence of small, reversible moves. Sanity, the Content Operating System for the enterprise, is designed for exactly this kind of incremental cutover: an intelligent backend where content is queryable structured data in Content Lake, where authoring lives in Sanity Studio, and where you can run new content models alongside your AEM estate instead of behind a freeze. That changes the roadmap from a cliff into a ramp.

This guide walks through how to build that roadmap: how to inventory an AEM install honestly, how to model content for the future rather than copying the past, how to run AEM and Sanity in parallel, and how to sequence the cutover so governance, compliance, and the content calendar all survive the move.

Start with an honest inventory, not a lift and shift

The first mistake enterprises make migrating off Adobe Experience Manager is treating the existing implementation as the specification. A decade-old AEM install accumulates dead templates, orphaned components, half-finished workflows, and content fragments that no page references anymore. Copy all of that into a new system and you have paid to migrate your technical debt.

Start instead with a content audit that measures reality. Pull usage analytics to find which templates and pages actually drive traffic and conversions. Catalog your component library and mark each component as keep, merge, or retire. Map every integration touching AEM: DAM, translation, personalization, commerce, analytics, and any homegrown Java services. Identify the workflows that carry real governance weight (legal review, regulated-industry approvals) versus the ones that exist because someone built them in 2016.

The output is a migration ledger: every content type, its volume, its owner, its downstream dependencies, and a disposition. This is where you decide what moves, what gets remodeled, and what quietly dies. It is unglamorous, and it is the single highest-leverage week of the whole project.

The payoff shows up later. Because Sanity treats content as structured data in Content Lake rather than as rendered pages, the audit doubles as the input to your content model. Every retained content type becomes a schema; every dependency becomes an integration you will rebuild deliberately with Functions or the App SDK rather than inherit by accident. You are not photographing the old house, you are drawing the new one.

Model your business, not your old page tree

AEM's page-and-component model encourages content that is shaped like the pages it renders. That coupling is exactly what makes the DXP hard to evolve: change the design and you touch the content, add a channel and you rebuild the templates. The migration is your one chance to break that coupling, and skipping it means you carry the constraint into the new system.

The discipline is to model your business domain rather than your presentation. A product is a product whether it appears on a web page, in a mobile app, in an email, or as grounding for an AI assistant. Model it once, with its real attributes and relationships, and let each channel query what it needs. In Sanity this is the Studio schema layer over Content Lake, where content is structured, queryable via GROQ, and reusable across every surface rather than trapped in a template.

This is the first pillar in practice: model your business. Resist the urge to recreate AEM's component granularity one to one. Instead, define content types around meaning (article, campaign, product, location, policy) and use references to compose them. Portable Text handles rich text without locking you into a rendering, and Studio Workspaces lets a multi-brand or multi-market estate live in a single, governed authoring environment rather than the sprawl of separate AEM instances many enterprises end up running.

Get the model right and the rest of the roadmap gets easier: parallel running is cleaner, integrations are simpler, and the next redesign is a frontend change instead of a replatform.

Run AEM and Sanity in parallel, cut over in slices

The single biggest risk-reducer in an enterprise migration is refusing to do it all at once. A big-bang cutover concentrates every risk (data, integrations, author training, SEO, performance) into one weekend and gives you no way to roll back gracefully. The alternative is the strangler pattern: stand up Sanity alongside AEM and migrate one slice of the site or one content domain at a time.

Concretely, pick a bounded, lower-risk surface first: a resource center, a blog, a single market, or a new campaign microsite. Model those types in the Studio, migrate their content into Content Lake, and route just those URLs to a new frontend that reads from Sanity while the rest of the estate still renders from AEM. A routing layer at the edge (or in your CDN) decides which system owns which paths. Each slice you cut over is a small, reversible deployment with its own go or no-go.

Because Content Lake exposes content over a global CDN as queryable structured data, the new frontend can go live for a slice without waiting for the whole catalog. Content Releases let editors stage and ship a batch of migrated content as a single unit, so a market launch is one atomic publish rather than a scramble of individual saves. And because you never freeze the whole content calendar, the marketing team keeps shipping in AEM for the slices that have not moved yet.

The parallel period is not overhead; it is the mechanism that lets you validate each slice against real traffic before it owns production. You learn on the resource center so you are not learning on the checkout flow.

Preserve governance, compliance, and audit continuity

Enterprise buyers do not get to trade governance for velocity, and the fastest way to kill a migration is to tell legal or security that the new system relaxes controls. Whatever AEM enforced (role-based access, approval chains, an audit trail of who changed what) has to have a credible equivalent on day one, and ideally an improvement.

Map your existing controls before you migrate a single field. Who can create, who can edit, who can publish, who signs off in regulated content, and what evidence you must retain. Sanity's governance primitives cover this: Roles & Permissions for granular access, SSO for identity, and Audit logs for the record of changes that compliance and security teams require. For data-residency obligations, Sanity offers regional hosting so EU content can stay in the EU. On the compliance posture, Sanity maintains SOC 2 Type II and GDPR compliance and publishes its sub-processor list, which is the documentation an enterprise security review will actually ask for.

Governance also improves in the move. Content Releases give you the editorial equivalent of a reviewable, atomic change set: a batch of edits staged, reviewed, and shipped together rather than a stream of individual publishes that are hard to reason about. As AI enters editorial workflows, that same reviewable loop matters more, because AI-generated or AI-assisted content needs the same approval and audit trail as anything a human wrote. Building the roadmap around these primitives means you can walk into the security review with answers, not aspirations, and that is often what actually unblocks the budget.

Rebuild integrations as deliberate services, not inherited glue

An AEM estate is usually surrounded by integration glue: OSGi bundles, custom Java services, workflow launchers, and connectors to DAM, translation, personalization, commerce, and analytics. Much of it is invisible until you try to leave, and treating it as a straight port is how a migration silently doubles in scope. The roadmap needs an explicit workstream for rebuilding integrations as clean, observable services.

Go back to the migration ledger and take each integration in turn. For every one, decide whether it is still needed, whether a managed integration replaces custom code, and where the logic should live. Sanity's approach favors composability over an everything-in-the-box suite: Functions run event-driven logic (translation kickoffs, moderation, compliance checks, AI enrichment) close to your content, and the App SDK lets you build custom tooling into the authoring experience. Translation is a concrete example: rather than an AEM translation connector, you can use the native plugin or integrate Phrase or Smartling for multi-market workflows.

This is the automate everything pillar. The goal is not to reproduce every piece of glue but to replace inherited, opaque behavior with logic you can see, test, and change. Content Source Maps help the analytics side of the house trace which content drove which outcome, closing a loop that AEM's rendered-page model often obscures. The counterintuitive result is that the integration workstream, usually the scariest part of an AEM exit, becomes the part where you retire the most cost, because a decade of custom bundles collapses into a handful of legible Functions.

Sequence, staff, and cost the roadmap end to end

A roadmap that lists phases without owners, dates, and a rollback story is a wish list. The final step is to sequence the work into named phases, staff each with clear ownership, and build the total cost of ownership case that the migration has to win to get funded.

A workable sequence: (1) inventory and audit; (2) content modeling and Studio setup; (3) first low-risk slice cut over in parallel; (4) governance and integration workstreams hardened against that slice; (5) progressive cutover of remaining domains, highest-traffic and highest-risk last; (6) AEM decommission once no path routes to it. Each phase has a go or no-go gate, and because slices are reversible, no single gate can sink the program. For large or multi-market rollouts, Sanity's Partner network of systems integrators can carry the implementation load rather than forcing a DIY build.

The cost argument is where enterprise buyers actually decide. Total cost of ownership is license plus implementation plus ongoing operations, and the legacy-DXP number is dominated by the operations and reimplementation tail. With Content Lake, you do not operate the content database, patch the servers, or size the infrastructure, which removes a standing operations cost that AEM carries indefinitely. The honest framing for the business case is not just that the new stack is cheaper, but that it is cheaper and faster to evolve: the next redesign is a frontend project, not another replatform. That is the number that ends the AEM license renewal for good.