Incremental Cloud Migrations
Not everything has to move at once. We migrate system by system, starting with whatever is hurting most, so you see results long before the project ends.
Why moving everything at once rarely goes well
The instinct with migration is to treat it as a single project with a start date, an end date, and a big switch in the middle. It reads well in a plan. It behaves badly in reality.
The problem is that all of the risk lands on one day, and none of the benefit arrives until then. If the cutover slips, everything slips. If one component turns out to be far harder than estimated, it holds up components that were ready months earlier. And the whole time, the team is maintaining two environments while shipping nothing new.
Incremental migration inverts that. You move one thing, confirm it works, and keep the improvement. Then you do the next one.
Starting where it actually hurts
The first candidate is not the easiest system, and it is not the one at the top of the org chart. It is the one costing you the most in a way you can point at.
That usually looks like one of a few things. An application that falls over under traffic it should handle. A server whose hosting bill has crept up year after year without anyone renegotiating it. A component so fragile that nobody wants to deploy changes to it, which quietly slows every project touching that area.
Any of these gives you a clear before-and-after. That matters more than people expect, because the second phase of a migration is much easier to justify when the first one produced a number you can show.
The first move is also a rehearsal
Whatever moves first will teach you more about your own estate than any planning document. That is a large part of its value, and it is worth choosing the first component with that in mind.
Almost every migration turns up the same category of surprise. A configuration value hardcoded somewhere nobody remembers touching. A scheduled job running on a machine that is not in any inventory. An integration authenticating by IP address, which stops working the moment the address changes. A dependency on a library version that the new platform does not offer.
Finding these on one contained system is inconvenient. Finding all of them at once, during a single cutover weekend, is how migrations end up in the stories people tell years later. The first phase is where you pay that cost cheaply.
The boundary between old and new
The part of incremental migration that gets underestimated is coexistence. For as long as the project runs, some of your system is in the cloud and some is not, and the two halves have to work together as if nothing had changed.
That means a few things have to be solved early rather than per component. Authentication has to work across both sides, so a user does not get logged out crossing an invisible line. Services need network paths to each other that are secure and reliably fast. Shared data needs a single owner. The most common failure here is two systems both writing to what they think is their own copy.
Building this properly during the first phase feels like overhead. It is what makes every subsequent phase routine.
Knowing when to stop
A migration plan does not have to end with everything in the cloud. That is worth saying plainly, because the assumption that it does causes a lot of unnecessary work.
After a few phases, the remaining systems are often the stable ones. They run on hardware that is paid for, they rarely fail, and nobody has needed to change them in two years. Moving them would cost real money and return very little. We review what is left periodically, and if the honest answer is that the rest should stay put, that is what we recommend.
The goal was never to be entirely in the cloud. It was to stop the infrastructure from getting in the way.
What you get
Priority list based on real pain
We rank your systems by failure frequency, hosting cost and how hard they are to change, then start where the return is clearest rather than where the diagram is tidiest.
A migration path per system
Each component gets its own plan. Some are a straight lift-and-shift, some need reworking first, and some are better left where they are for now.
Coexistence between old and new
During the transition, migrated and unmigrated parts have to keep talking to each other. We design that boundary explicitly instead of discovering it mid-project.
Shared identity and data access
Users should not notice which half of the system they are in. Authentication and shared data are handled once, at the start, rather than patched per component.
Cost visibility as you go
Each migrated piece has its old and new running cost measured, so the business case is built from actual numbers rather than a forecast made a year earlier.
A stopping point you can live with
A partial migration should be a stable end state, not a half-finished project. Every phase leaves the system in a shape you could stay in indefinitely.
How we work
- 01
Audit and prioritise
We review the current estate: what runs where, what it costs, what breaks. The output is an ordered list with the reasoning attached, not just a diagram.
- 02
Migrate the first component
The first move is deliberately something valuable but contained. It proves the approach, exposes the surprises early, and gives the team a template for the rest.
- 03
Establish the boundary
Networking, authentication and data access between the cloud and whatever is still on-premise get built properly during the first phase, because everything after depends on them.
- 04
Repeat and measure
Each subsequent component follows the same pattern, with cost and reliability compared before and after so the next decision has evidence behind it.
- 05
Review the remainder
Periodically we reassess what is left. Sometimes the right answer is to stop. The remaining systems are stable, cheap, and not worth moving.
Tools and technology
Where a solid open-source tool exists, we choose it over a closed one. No lock-in to a single vendor, and costs you can actually predict.
- OpenTofu
- Terraform
- Docker
- Kubernetes
- PostgreSQL
- Keycloak
- Traefik
- Grafana
- AWS
- Microsoft Azure
- Google Cloud
- Cloudflare
Frequently asked questions
More services in this category
Zero-Downtime Cloud Migrations
Some systems cannot be switched off for a weekend. We migrate them while they keep serving customers, with a rollback path at every step.
Infrastructure Modernization Sprints
A short, focused engagement that fixes the infrastructure problems actually costing you something, without committing to a project that runs for months.
Serverless Architecture and Scale-to-Zero
Your code runs when it is needed and costs nothing when it is not. For workloads with uneven traffic, that changes the economics of running a system.
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Which system is hurting you most right now?
Message usTell us what breaks most often or costs the most to run, and we will suggest where an incremental migration should start and where it can safely stop.
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