Most hybrid projects do not fail with an outage. They stall at 60 percent, because connectivity, identity or data movement was assumed instead of designed. This guide covers the four things that have to be right before workloads start moving between your data centre and a public cloud.
Scroll sideways to see the whole diagram →Numbered lines show what crosses between the two environments. Everything crosses over the private link, never the open internet.
Part
What it does
1 Application traffic
Cloud applications call core systems and the other way round. Keep these calls few and coarse: chatty traffic across a WAN link is slow and, in the cloud, billed.
2 Identity sync
Users and groups are synced from Active Directory to the cloud identity service, so people use one account and one password everywhere.
3 DNS forwarding
Each side can resolve the other's names. Without this, applications break in confusing ways after migration.
4 Private connectivity
A dedicated link such as AWS Direct Connect, Azure ExpressRoute or OCI FastConnect, with an IPsec VPN as backup. Sized from measured traffic, not guessed.
5 Data copies
Large datasets stay where they are used. Only what is needed is copied, on a schedule, with egress cost in mind.
Four things to get right first
Classify every workload. Decide for each application whether it stays, moves as-is, or is rebuilt for the cloud. Moving a VM unchanged is fine for some systems and expensive for others.
Design connectivity early. A VPN added late becomes the bottleneck and single point of failure for every hybrid workload. Order dedicated links early: provisioning can take weeks.
One identity, not two. If on-premises and cloud accounts are managed separately, you get two logins, two audit trails and a clean-up project nobody planned.
Respect data gravity. Large databases cannot move overnight. Plan how data is synced, how long the first copy takes, and what the final cutover window looks like.
Typical tools
Layer
Common choices
Private links
AWS Direct Connect, Azure ExpressRoute, OCI FastConnect, IPsec VPN as backup
Identity
Active Directory with Microsoft Entra Connect, AWS IAM Identity Center, OCI Identity Domains
Send us a VM inventory export (RVTools is fine) and a line on what is driving the change. We will come back with a plain first view: what could move where, in what order, and roughly what it would cost to run.