In recent years, the public cloud has established itself as an essential accelerator of digital transformation. Its promises of on-demand scalability, operational flexibility and pay-as-you-go cost models are seductive, especially for businesses looking for agility and time-to-market. However, behind this enthusiasm lies a problem that is often relegated to the background: technological dependence on a single supplier. A dependency that, if not anticipated, can compromise digital sovereignty, increase exit costs and limit strategic room for manoeuvre.
Cloud reversibility, i.e. the ability to take back control of data, applications and infrastructure and rehost them elsewhere, is therefore becoming a critical governance issue.
Why is cloud reversibility a major issue?
A risk of vendor lock-in
The big cloud providers - the "hyperscalers" as they are known - are the ones who have the most to lose. AWS, Microsoft Azure or Google Cloud - offer powerful proprietary services that are often very well integrated, but not very interoperable. A company that builds its IS around services such as AWS Lambda, Azure Functions, BigQueryor Cloud Spanneris soon faced with a structural dependency.
Underestimated exit costs
Leaving the cloud can be accompanied by significant technical, financial and operating costs. The outgoing data transfer fees (egress fees) can become a real financial trap. For example, transferring 10TB of data from AWS to another cloud or data centre can generate costs of over €1,000, not including any redeployment costs.
In addition, some contracts include restrictive clauses on data recovery, retention periods or early penalties, making exit even more complex.
Increasing regulatory constraints
Regulators are demanding more and more guarantees that the location, traceability and retrievability of data. Le RGPD requires companies to know where personal data is stored at all times, and to be able to delete or transfer it at any time. In sectors such as healththe public sectoror financial servicesthe challenges of compliance and sovereignty require tried and tested reversibility mechanisms.
How do you build an effective reversibility strategy?
A reversibility strategy cannot be improvised at the end of a project. upstreamright from the design phase of the cloud architecture. Here are the key levers to mobilise:
Favour interoperable and portable architectures
The adoption of open standards avoids services that are too specific to one cloud provider. In addition, the use of multi-cloud-ready as OpenShift or HashiCorp Vault makes transitions easier.
For example, you can use :
- Kubernetes for container orchestration,
- Terraform for infrastructure management (IaC),
- RESTful APIs for application exchanges.
Structuring data governance
Data formats and processing tools must also be chosen with care. Opt for formats open and interoperable (JSON, CSV, Parquet) and integration solutions such as Apache NiFi, Airbyte or Apache Airflowwhich make it easier to synchronise or migrate to another environment.
It is also essential to put in place a data mapping (Data Catalog) and clear documentation of the technical architecture to guarantee a controlled transfer.
Incorporating reversibility into contracts
When contracting with a cloud provider, make sure you include :
- A reversibility clause This will include a clear description of how the data will be retrieved, the expected formats, deadlines and support commitments.
- From exit cost clausesincluding egress charges and any breakage penalties.
- A period of coexistence or double runallowing for a gradual migration.
European or sovereign players are now offering reversible by design" offerswith multi-cloud compatible infrastructures and SLAs that take these requirements into account.
Cloud reversibility is one of essential to a sustainable, sovereign and responsible cloud strategy. Companies that include it from the outset of their projects retain their freedom of action, control their costs more effectively and respond to regulatory requirements with greater peace of mind.
At Cloud Temple, by building open, documented and governed architectures, we provide our customers with strong guarantees of reversibility.without dependency.