What is cloud migration?

This process involves moving data, applications and workloads from an on-premises environment to cloud infrastructure. Given the technical and organisational challenges this transition poses, understanding the fundamentals and adopting a methodical approach is essential.

Understanding cloud migration: definition and stakes

Cloud migration is the process of transferring digital resources—data, applications and IT services—from an on-premises environment to the cloud. This transition may also involve moving from one cloud to another, depending on the organisation’s evolving needs.

Organisations typically choose to migrate to the cloud to optimise their infrastructure, reduce costs and support their digital transformation. In a context where this transformation is accelerating, this approach becomes essential to remain competitive.

Moving to the cloud offers an alternative to the constraints of traditional systems. Rather than investing in physical servers and bearing associated maintenance costs, organisations can access scalable infrastructure that adapts to their needs.

By migrating to the cloud, you obtain a flexible environment where computing resources are automatically adjusted according to your actual needs. This approach fundamentally transforms how you manage your IT infrastructure.

Different types of cloud migration

Several approaches exist for migrating to the cloud, each addressing specific needs.

Complete migration from a data centre

This type of migration involves transferring all data, applications and services from one or more data centres to public cloud. This process requires rigorous planning and can extend over several months or even years.

Migration to hybrid cloud

In this configuration, some resources are moved to the public cloud whilst others remain in on-premises infrastructure. This approach allows organisations to benefit from their current investments whilst exploiting cloud advantages. It’s also common for organisations to outsource backup hosting to increase their security and resilience levels.

Cloud-to-cloud migration

Organisations may wish to move their resources from one cloud provider to another for various reasons, including taking advantage of specific pricing, features, enhanced security or new tools.

This strategy can also be part of a multi-cloud approach, where multiple providers are used in parallel to avoid dependency on a single actor, optimise costs or distribute loads more precisely according to business needs.

Specific workload migration

Rather than migrating their entire infrastructure, some organisations choose to move only particular workloads. This targeted strategy can constitute a first step before a more complete migration.

Cloud migration strategies

To succeed in your cloud migration, several strategies are available. The choice will depend on your objectives, current infrastructure complexity and technical constraints.

Lift and Shift

Lift & Shift involves moving applications to the cloud with little or no modification. Originally presented as a key promise of cloud computing, this rapid approach seems attractive, but in reality, it rarely works efficiently. Indeed, it often leads to very high costs linked to infrastructure not optimised for the cloud and degraded performance, with legacy applications retaining their original limitations without benefiting from native cloud capabilities.

Platform change (Lift and Optimise)

This strategy involves migrating applications whilst partially adapting them to better exploit cloud functionalities (managed database, scaling services, integrated monitoring, etc.). For example, a human resources management application might see its obsolete database replaced by an automated cloud service. Although longer to implement than simple Lift & Shift, this approach allows better optimisation of performance and resilience.

Refactoring

Refactoring requires rethinking application architecture to fully exploit native cloud functionalities. This approach allows considerable performance improvements but requires greater investment in time and resources.

Replacement with SaaS solution (Repurchase)

Rather than migrating an existing application, some organisations choose to replace it with a ready-to-use SaaS solution. For example, a locally installed ERP might be abandoned in favour of a cloud alternative accessible via a browser. This strategy reduces technical complexity but requires adapting to the functional constraints of a standardised tool.

Retirement

In some cases, pre-migration analysis reveals that certain applications have become obsolete or redundant. Retirement involves deactivating these applications, which simplifies architecture and reduces costs. The critical functionalities they covered must then be either transferred to other existing tools, redeveloped, or simply abandoned if they no longer present business value.

Benefits of cloud migration

Cloud migration offers numerous benefits that explain why so many organisations take the plunge.

Scalability and flexibility

Cloud infrastructure can be quickly resized to meet fluctuating business needs. This elasticity avoids over-provisioning hardware to handle occasional demand peaks.

Auto-scaling offered by Clever Cloud automatically adjusts resources allocated to your applications. Whether your traffic increases or decreases, your infrastructure adapts in real-time to guarantee optimal performance whilst controlling costs.

Enhanced security

Major cloud providers invest heavily in security to protect their infrastructure and your data. These investments translate into robust security measures, including encryption, multi-factor authentication and regular audits.

Clever Cloud integrates security from the design of its services, with a systemic rather than reactive approach. This translates into:

• Immutable infrastructure: each deployment occurs in a clean environment, avoiding software drift
• Continuous security monitoring (MCO)
• Automatic system image updates as soon as a critical vulnerability is detected
• Security patches applied without manual intervention, guaranteeing better responsiveness than in most traditional environments

Improved performance

By migrating to the cloud, you benefit from the latest advances in server and network technology, ensuring faster processing speeds and optimal performance for your applications.

Clever Cloud clients report significant performance gains. For example, AmphiBee agency saw average loading times reduced by three after its migration, dropping from 6 seconds to just 1 second for certain critical operations.

Continuous innovation

Cloud providers maintain their infrastructure up-to-date with the latest technologies and security patches. They also offer regular updates integrating new functionalities, allowing you to stay at the cutting edge without additional effort.

Clever Cloud, as a French cloud player, constantly invests in innovation to offer increasingly high-performing and environmentally-friendly cloud services, whilst also enriching its add-on marketplace, including:

• Keycloak as a Service for identity management (IAM);
• Azimutt for visually exploring your databases;
• Materia, our own serverless database;
• OCamlPro for running COBOL on the cloud.

These services are accessible directly from our console, CLI, API or via Terraform, and can be integrated into your existing workflows.

Cloud migration challenges

Despite its numerous advantages, cloud migration presents certain challenges that should be anticipated.

Technical complexity

Migrating interdependent applications can prove complex. Legacy systems may be incompatible with cloud environments and require significant refactoring.

At Clever Cloud, we don’t directly perform migrations, but we collaborate with a network of specialised partners capable of supporting the most complex projects. Our tools then allow you to fully benefit from PaaS infrastructure once applications are migrated.

Change management

When migrating to a SaaS application, the organisation may need to modify certain practices to adapt to the new solution. This organisational change must be anticipated and supported to guarantee team adoption.

Security and compliance

Cloud migration requires rethinking security strategies and ensuring data remains protected during and after transfer. Regulatory compliance issues must also be addressed, particularly in heavily regulated sectors.

Clever Cloud, as a French sovereign cloud, guarantees strategic autonomy of your data and their hosting on European infrastructures. Our security commitment translates into a rigorous certification policy:

• ISO 9001: quality management;
• ISO/IEC 27001:2022: information security management;
• HDS (Health Data Hosting): certification obtained across all 6 standard activities, guaranteeing secure, compliant hosting of personal health data;
• SecNumCloud: certification in progress, with the possibility of hosting your data on a certified Cloud Temple partner zone to meet trusted cloud requirements.

These certifications demonstrate our ability to support organisations with high requirements, particularly in healthcare, by offering reliable, high-performing PaaS and DBaaS cloud infrastructure that complies with the strictest standards.

Cost management change: CAPEX vs OPEX

Moving from on-premises infrastructure to a cloud model implies structural change in budget management. We generally move from a CAPEX (capital expenditure) model to an OPEX (operational expenditure) model.

This change can be surprising as it may in some cases reduce initial investments but involves recurring costs linked to resource consumption (CPU, RAM, storage, etc.).

This evolution requires adapting financial management practices, better predictability of usage, and sometimes acculturation of accounting teams or CFOs. It also opens the way to better financial elasticity, closer to the organisation’s real needs.

Key steps to successful cloud migration

Successful cloud migration relies on a structured approach and good understanding of technical, organisational and financial issues. Here are the essential steps to follow.

1. Needs analysis and requirements definition

Before anything else, understanding migration objectives is crucial. Is it about reducing costs? Improving resilience? Modernising infrastructure?

From this analysis, develop clear requirements that specify:

• Applications and data to migrate;
• Regulatory constraints;
• Performance and security requirements;
• Expected service level (IaaS, PaaS, SaaS).

This step is crucial for guiding technical and organisational choices for the rest of the project.

2. Cloud provider selection

Based on your needs, identify the provider whose offering best meets your requirements. The choice between IaaS (Infrastructure as a Service) or PaaS (Platform as a Service) will strongly influence how migration is conducted.

Clever Cloud, as a 100% French PaaS provider, allows you to deploy your applications without managing low-level infrastructure layers, guaranteeing data sovereignty, transparent and predictable pricing, and infrastructure designed for automation, performance and security.

3. Migration planning and timeline

Once the provider is selected, build a realistic migration plan:

• Prioritise applications to migrate;
• Define technical dependencies;
• Plan validation milestones;
• Develop fallback plans for unexpected issues.

The timeline will directly depend on chosen solutions.

4. Application and Data Migration

The actual migration stage typically begins with test environments or non-critical applications. The objective is to validate methodology and adjust processes before moving to sensitive or strategic components.

5. Testing and Validation

Verify that migrated applications function as expected:

• Load testing;
• Security testing;
• Performance and integration verification.

Ensure teams are ready to operate in the new environment.

6. Continuous Optimisation and Monitoring

Once in production, monitor usage, performance and costs. Identify optimisation levers to improve your cloud infrastructure efficiency.

Clever Cloud offers continuous integration and automated deployment tools that optimise post-migration workflows, streamline updates and strengthen application resilience over time.

Cloud Service Models to Consider

During your cloud migration, you’ll need to choose between different cloud computing service models based on your specific needs.

Infrastructure as a Service (IaaS): maximum customisation but increased complexity

IaaS allows organisations to rent computing resources—servers, virtual machines, storage, networks—from a cloud provider. This model offers great flexibility: you can scale your resources (scale-up/scale-down) according to demand and only pay for what you actually consume.

However, this freedom comes with significant technical responsibility: maintaining operational conditions of systems (OS, databases, runtimes, etc.) remains the client’s responsibility. This often requires internal skills or recourse to managed services. In short, IaaS suits organisations needing very specific architecture, but it can be costly and time-consuming to manage.

Platform as a Service (PaaS): automation and time savings

PaaS offers IaaS infrastructure advantages but also includes managed development tools, databases, analytics and operating systems. This solution is ideal for reducing development costs and time-to-market.

Clever Cloud is a PaaS provider distinguished by its ease of use and high level of automation. Our platform allows developers to focus on their code whilst all underlying infrastructure is automatically managed.

Software as a Service (SaaS): ease of use but limited flexibility

SaaS provides access to applications via the Internet, often on subscription. Hosting, maintenance and updates are managed by the provider. This model eliminates local installation constraints, simplifying users’ daily lives and limiting technical costs.

However, this simplicity has a downside: customisation possibilities are often restricted. SaaS perfectly suits organisations wanting to quickly standardise their tools (CRM, office suites, collaboration tools), but it may prove too rigid for organisations with specific business needs or strong technological sovereignty requirements.

Simplified cloud migration, enhanced performance and guaranteed sovereignty

Clever Cloud offers a unique approach to cloud migration, combining simplicity, performance, security and digital sovereignty.

Our PaaS platform fully automates infrastructure management, allowing development teams to focus on their code: “You code. We handle the rest.”

Thanks to our optimised architecture and intelligent auto-scaling system, applications always benefit from necessary resources without over-provisioning. Result: consistent performance, controlled consumption, and significant reduction in your bill. Meanwhile, our European-based data centres ensure GDPR compliance and data protection within a sovereign legal framework. Our security relies on immutable infrastructure and trusted network prevention, guaranteeing enhanced protection.

To support your transition, our France-based support team guides you throughout: needs assessment, seamless migration, continuous optimisation.

Client testimonials: successful migrations to Clever Cloud PaaS

AmphiBee reduces costs and improves performance

AmphiBee, a web agency specialising in WordPress and WooCommerce, migrated to Clever Cloud to solve slowness, stability and technical rigidity problems.

This migration achieved Google PageSpeed scores above 90/100 whilst controlling maintenance costs. Concrete proof that a good hosting choice can transform team performance and efficiency.

Guest Suite: From IaaS to PaaS for greater peace of mind and performance

Guest Suite, a Nantes-based editor of SaaS solutions dedicated to e-reputation, made the strategic choice to migrate its IaaS infrastructure to Clever Cloud’s PaaS.

Whilst redesigning its platform, the team sought to gain scalability, simplicity and autonomy. Thanks to Clever Cloud, it could rely on sovereign, automated and high-performing hosting.

In less than two months, all applications were migrated without service interruption. Each step was supervised with responsiveness by the Clever Cloud team.

Today, more than half of Guest Suite’s clients use the new platform hosted at Clever Cloud. A successful migration that allows teams to focus on their business: helping companies master their online image.

Application integration and deployment in the cloud

Once the decision to migrate to the cloud is made, deploying your applications becomes a crucial step. Clever Cloud considerably simplifies this process through advanced automation and tools specially designed for developers.

More complex applications also benefit from this simplicity, with support for numerous programming languages like Java, PHP, Python, JavaScript, Ruby, Go and many others. This versatility allows practically any application to be migrated to their platform.

For databases, Clever Cloud offers fully managed services like PostgreSQL, MySQL, MongoDB, Redis®, Elastic and Materia, thus eliminating all complexity of managing these critical systems.

Innovation and emerging technologies in the cloud

Cloud migration also opens doors to adopting emerging technologies that can transform your business. Clever Cloud continuously integrates these innovations into its platform to allow you to benefit from them.

Artificial intelligence is a good example. Clever AI, our AI solution, allows aggregating language models (LLM), integrating them into an identity management system (IAM), making them available via a conversational interface and defining usage policies compliant with business requirements. Based on the open-source Otoroshi gateway and developed with Cloud APIM, Clever AI adapts to your constraints: serverless deployment, on dedicated instances or on-premises, with traceability and centralised data control.

To go further, Otoroshi with LLM is available as an add-on. It facilitates managing your APIs and AI providers (OpenAI, Anthropic, Hugging Face, Mistral, OVHcloud, Scaleway, etc.) in a unified environment controllable directly from Clever Cloud.

Object storage is another area where cloud brings significant advantages. Cellar, Clever Cloud’s object storage service, offers a sovereign, reliable and scalable solution for storing and distributing your files. Compatible with Amazon S3 API, Cellar allows you to benefit from a known ecosystem whilst keeping control of your data through European hosting respecting GDPR standards.

Migrating to the cloud: a strategic lever

Migrating to the cloud isn’t just about changing infrastructure. It’s about rethinking how you design, deliver and evolve your services.

With Clever Cloud, you automate resource management, gain performance and keep control of your data—securely.

Real change begins when your teams can finally focus on what matters: creating value.

Key takeaways on cloud migration

• Migrating to the cloud means moving your data, applications and workloads from your on-premises infrastructure to cloud infrastructure. This transformation becomes essential to remain competitive in an accelerated digital transformation context.
• Four migration types exist: complete data centre migration, hybrid cloud migration, cloud-to-cloud migration, or targeted migration of only certain workloads.
• Five main strategies are available: Lift & Shift which rarely works efficiently despite its promise of speed, Lift and Optimise to partially adapt applications, refactoring to fully exploit cloud-native, replacement with SaaS solution, or retirement to simplify by eliminating obsolete elements.
• Benefits are concrete: automatic scalability according to your real needs, enhanced security with immutable infrastructure and automatic updates, improved performance up to 3 times faster, continuous innovation and financial flexibility with transition from CAPEX to OPEX model.
• Successful migration requires six key steps: needs analysis and requirements definition, cloud provider selection, planning and timeline with validation milestones, methodical application migration, thorough testing, then continuous optimisation.
• Three cloud service models exist: IaaS offers maximum customisation but with increased management complexity, PaaS fully automates management to focus on code, and SaaS simplifies usage but limits flexibility.
• Challenges to anticipate include technical complexity of interdependent systems, organisational change management, security and regulatory compliance issues, and adaptation to CAPEX to OPEX budget change.
• To simplify your migration, Clever Cloud offers a French PaaS platform that fully automates infrastructure management. Result: your teams focus on code whilst auto-scaling and per-second billing optimise performance and costs.
• Migrating to sovereign cloud addresses growing compliance issues. With its ISO 27001, complete HDS on 6 activities and ongoing SecNumCloud qualification certifications, Clever Cloud guarantees your migration respects strategic autonomy and GDPR compliance.
• Successful migration opens access to tomorrow’s technologies: secure AI integration with Clever AI, simplified API management with Otoroshi, and sovereign object storage with Cellar to support your post-migration growth.
• Migrating to the cloud fundamentally transforms how you design and deliver your services. Real change begins when your teams can finally focus on what matters: creating value.

FAQ on cloud migration

How long does cloud migration take?

Cloud migration duration depends on your infrastructure complexity and strategy. Simple migration can take a few weeks. For larger projects, expect 6 to 18 months, with typical breakdown: 30% planning, 50% execution, 20% optimisation.

How do you ensure data security during migration?

Security during migration relies on several pillars: data encryption in transit, strong authentication to control access, and rigorous testing at each stage. Choosing a provider like Clever Cloud, which integrates security from design, guarantees optimal protection throughout the process.

What are the hidden costs of cloud migration?

Moving to cloud doesn’t always mean immediate cost reduction, but rather economic model change: moving from heavy investments (CAPEX) to operational expenses (OPEX). Some charges are often underestimated: team training, application adaptation, data transfer fees or exit costs with certain providers. Clever Cloud distinguishes itself through transparent pricing, without hidden fees or constraining commitments, for better budget control.

How do you choose between complete migration and hybrid approach?

This choice depends on several factors: regulatory constraints, data sensitivity, required performance and available budget. Hybrid approach allows progressive transition whilst keeping certain critical systems on-site. Precisely evaluate your current and future needs to determine optimal strategy for your organisation.

What skills are needed to manage a cloud environment?

Managing a cloud environment requires skills in cloud architecture, automation, network security and data management. However, with a PaaS solution like Clever Cloud, these needs are considerably reduced since the platform automates most infrastructure tasks, allowing your teams to focus on application development.

How do you minimise risks during migration?

Adopt progressive approach by first migrating non-critical applications. Perform exhaustive testing at each stage and prepare detailed rollback plans. Train your teams in cloud technologies and benefit from expert support to secure the transition.

How do you choose between public, private or hybrid cloud?

Evaluate your security, regulatory compliance and performance requirements. Public cloud optimises scalability and innovation. Private cloud meets enhanced security needs. Hybrid combines operational flexibility and sensitive data control.

What to do if a legacy application cannot migrate?

Analyse specific technical and regulatory constraints. Consider virtualisation, containerisation or temporary on-premises maintenance. Also evaluate replacement with equivalent SaaS solutions or progressive module-by-module refactoring.

How do you measure cloud migration success?

Define technical and business KPIs that best correspond to your challenges: cost reduction, performance improvement, deployment time, service availability and user satisfaction. Also measure business agility and your technical teams’ innovation capacity.

Is cloud migration reversible in case of problems?

Portability depends on your initial strategy and technological choice. Favour open standards and avoid constraining vendor lock-in. Precisely document your architecture and maintain capacity for migration to other platforms if necessary.

What skills should be developed for successful migration?

Train your teams in cloud-native architectures, DevOps, containers and microservices. Develop expertise in monitoring, cloud security and FinOps. Support from cloud experts accelerates this essential skill development.