Cloud Migration Consulting: 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.

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.