Cloud Migration Services: Move Fast Without Breaking Security

If your business handles Controlled Unclassified Information (CUI) or ITAR-controlled technical data for the Department of Defense, commercial Microsoft 365 generally can't satisfy DFARS 252.204-7012 or your CMMC obligations. Essendis — a Microsoft Government Cloud reseller and AOS-G partner — plans and executes tenant-to-tenant migrations from commercial Microsoft 365 to GCC High: email, files, Teams, and the CUI workflows around them, with coexistence planning so your team keeps working through the cutover.

Many contractors pair a GCC High migration with a scoped CMMC secure enclave, isolating CUI to shrink both the migration effort and the assessment boundary.

Every Essendis migration follows the same disciplined, security-first sequence — the kind of process that keeps your business running while your infrastructure moves.

01 — Assess

We inventory workloads, dependencies, data sensitivity, and compliance obligations. Not sure the cloud is right for a workload? A cloud assessment answers that before you commit a dollar.

02 — Design

We architect the target environment — identity, networking, encryption, conditional access — and validate the approach with a proof-of-concept.

03 — Migrate

Applications and data move in planned waves, with rollback points and coexistence so your users are never stranded mid-move.

04 — Validate

We test performance, security controls, and compliance mapping against the design before anything is decommissioned.

05 — Operate

Keep it running with managed cloud services: cost control, patching, monitoring, and ongoing security management.

Our cloud migration services start with a migration assessment. Pairing cloud assessment and migration means you have a fact base before any workload moves. It also shows which workloads should stay where they are for now.

The assessment identifies your current security posture and the performance requirements each application must meet. It lists the data centers and hosts you can retire once the move is complete. It maps the dependencies between applications so that related systems move together.

The findings set the target cloud environments for each workload, such as Azure or Microsoft 365. Where CUI or International Traffic in Arms Regulations (ITAR) data is in scope, the target is usually GCC High. GCC High is Microsoft's Government Community Cloud High, and our Microsoft GCC High migration service covers that move.

The assessment also sets the data migration approach. It decides what moves first, what moves together, and where the rollback points sit. The results feed a cloud adoption roadmap that orders the work into planned waves.

The roadmap then sets cost expectations for the long term. It explains the cost drivers of your current estate and of the target design. Any figures come from your actual workloads, not from generic estimates.

What Migration-Ready Means

A workload is migration ready when four prerequisites are in place and verified. Identity: accounts, roles, and multifactor authentication are configured in the target environment. Network: connectivity, name resolution, and firewall rules have been tested from end to end.

Backup: source data is backed up, and a test restore has succeeded. Monitoring: logging and alerting run in the target environment before any users move. To begin, see our cloud assessment services or the wider cloud assessments and migrations overview.

The migration assessment assigns a strategy to each workload. Most workloads fit one of three: rehost, replatform, or refactor. A few are retired or left in place.

Rehosting moves a server to the cloud as it is. It is the fastest route and carries the least application risk. The new cloud environments inherit the old sizing, so the running cost rarely drops on its own.

Replatforming changes the platform under an application without changing its code. Common examples are moving a database to a managed service or a file server to SharePoint. The data migration is larger, and the operating burden is smaller afterwards.

Refactoring rebuilds an application for cloud services such as containers or serverless functions. It costs the most up front and suits applications you plan to keep for the long term. We recommend it only where the assessment shows a clear return.

Where significant cost savings exist, they come from retiring data centers, right-sizing servers, and dropping unused licenses. They rarely come from the move itself. The assessment models these drivers for your workloads before you choose a strategy.

Retiring a workload means switching it off after its data is archived or moved. Retaining means leaving it where it is until a contract, hardware cycle, or dependency changes. Both are valid outcomes of a cloud assessment and migration plan.

Most migration shops bolt security on at the end. Essendis cloud engineers work under the same roof as security advisors — former Big Four auditors — so encryption, identity and conditional access, logging, and compliance mapping (GDPR, PIPEDA, HIPAA, CMMC) are baked into the migration design from day one, not retrofitted after go-live. It's the same integrated approach that helped AgilityHealth streamline how it manages security audits.

How much downtime should we expect?

Our goal is zero user-facing downtime for most workloads. Migrations are staged in waves with coexistence between old and new environments, and cutovers are scheduled around your business calendar. Some workloads — legacy databases, heavily customized applications — may need a brief maintenance window, which we identify in the assessment phase.

How long does a cloud migration take?

It depends on workload count, data volume, and compliance requirements. A single-tenant Microsoft 365 move is typically measured in weeks, while a multi-workload datacenter exit can run several months. The assessment phase produces a timeline you can actually plan around.

What drives the cost of a migration?

Data volume, application count and interdependencies, compliance requirements — a GCC High migration carries licensing and scoping decisions a commercial move doesn't — and how much post-migration management you want handled for you.

Do we need GCC High?

Only certain organizations do — typically defense contractors handling CUI or ITAR-controlled data under DFARS 252.204-7012. If that's you, commercial Microsoft 365 generally won't satisfy paragraphs c–g of the clause. If you're not sure, that's the first question our advisors answer.

What is the difference between a cloud assessment and a cloud migration?

A cloud assessment is the analysis stage. It inventories workloads, dependencies, and compliance obligations, then recommends a target and a strategy for each. A cloud migration is the execution stage, where workloads move in planned waves and are validated against that design.

Can you move us from AWS or Google Cloud to Azure?

Cloud to cloud migration is one of our core services. The assessment maps each service on the source platform to its equivalent on the target. Anything without a direct equivalent is flagged for redesign before the move.