In the digital era, organizations are under constant pressure to innovate faster, reduce operational costs, and improve security and scalability.
One of the most effective ways to achieve this is by moving from traditional on-premise infrastructure to cloud computing models — Infrastructure as a Service (IaaS), Platform as a Service (PaaS), and Software as a Service (SaaS).

This shift is not about using a specific provider such as Azure, AWS, or Google Cloud.

It’s about adopting a more flexible, efficient, and future-ready way of managing IT resources.

From On-Premise to Cloud — The Paradigm Shift

Traditional on-premise systems require heavy investments in physical servers, networking equipment, software licenses, and maintenance staff.
Cloud computing eliminates this burden by delivering infrastructure, platforms, and software as on-demand services over the internet.

Instead of owning and maintaining everything, companies rent only what they need, when they need it.

IaaS vs SaaS vs PaaS 

Cloud providers provide three main cloud service models: 

1. Infrastructure-as-a-Service (IaaS) 
2. Platform-as-a-Service (PaaS) 
3. Software-as-a-Service (Saas)

The image above shows your (users) responsibilities per model versus what the cloud provider takes on its hurdle.  

Being on-prem means you manage every part of the data center. But by moving towards the cloud, you can hand over responsibility to the cloud provider; it all depends on the model you pick. Let’s explain. 

Infrastructure-as-a-Service (IaaS) 

IaaS offloads all your traditional hardware you had in on-prem environments. You’re left with managing the OS, runtime and apps, as the service provider handles the rest of your infrastructure (like networking, storage, etc.). IaaS allows you to scale up new VMs in minutes, not weeks. And there’s no more need to buy expensive servers upfront.   

The building blocks for your architecture from IaaS services are VMs, VDI, Disc Storage and Virtual Network. This model is ideal for applications requiring high customization or legacy workloads.

Platform-as-a-Service (PaaS) 

PaaS shifts responsibility (such as the OS, runtime, and VMs) towards the service provider. It removes the hassle of infrastructure management so you can focus on building and deploying web apps with very little hassle, such as with App Service. 

SQL serves your relational database needs. Even so, other PaaS offerings include Functions (or Lambda), which runs event-driven code on demand, and Logic Apps, which automate workflows with pre-built connectors.

Software-as-a-Service (SaaS) 

SaaS takes it even further by taking care of everything, leaving you to manage only the data and software you use. Here, you don’t need to install or maintain the software; you access it via a web browser. SaaS is easy to use and maintain, and the service provider manages the updates and patches. 

Examples of SaaS (Software as a Service) include Microsoft 365 and Dynamics 365. It’s a good idea to switch to SaaS if your app is highly automated and web-based (such as when it doesn’t require specific Operating System or middleware).

From On-Premise to the Cloud: How to Successfully Migrate to IaaS, PaaS, and SaaS

In today’s fast-paced digital economy, cloud migration has become more than just a trend — it’s a necessity for companies that want to stay agile, scalable, and cost-effective.
Businesses that continue to rely on on-premise infrastructure often face limitations such as high maintenance costs, slow scalability, and outdated technologies that hinder innovation.

Migrating to the cloud — whether through Infrastructure as a Service (IaaS), Platform as a Service (PaaS), or Software as a Service (SaaS) — empowers organizations to modernize their operations, enhance security, and focus on what truly matters: delivering value to customers.

But successful migration doesn’t happen overnight.
It requires careful planning, assessment, and execution, often with the help of an experienced cloud migration partner.
Here’s a detailed look at how companies can prepare for and execute a smooth transition from on-premise systems to the cloud.

Phase 1: Assessment and Readiness Analysis

The first step in any cloud migration journey is understanding what you currently have. Before moving anything to the cloud, your organization needs to perform a comprehensive infrastructure and application assessment.

Inventory and classification

Start by identifying all your existing assets — servers, databases, applications, storage systems, and network configurations. Classify them based on:

• Business criticality
• Performance requirements
• Security and compliance needs
• Dependencies between systems

This step helps you determine which workloads are ready for migration and which may need modernization or replacement.

Readiness evaluation

Evaluate the technical readiness of your environment and team. Questions to ask include:

• Are your applications cloud-compatible?
• Do you have the right security policies in place?
• Are your employees trained to manage cloud-based systems?

Define your migration goals

Clearly define why you are migrating.

Common objectives include reducing costs, increasing scalability, improving performance, and enhancing security. Having measurable goals ensures the migration effort delivers tangible business outcomes.

Read on: How Secure Are Your Cloud Migration Pipelines?

Phase 2: Choosing the Right Cloud Model (IaaS, PaaS, or SaaS)

Each cloud model offers unique advantages. The right choice depends on your business needs, technical maturity, and long-term strategy.

IaaS (Infrastructure as a Service)

Iaas is ideal for companies that want to move their infrastructure as-is (a “lift and shift” approach). You get complete control over virtual machines, storage, and networking while the cloud provider manages the physical infrastructure.

Example use case:

Migrating virtual machines, file servers, or backup solutions to Azure Virtual Machines or AWS EC2.

PaaS (Platform as a Service)

This is best for organizations that want to modernize applications without managing operating systems or runtime environments. The provider manages infrastructure and scalability, freeing your developers to focus on innovation.

Example use case:

Deploying web applications using Azure App Service, AWS Elastic Beanstalk, or Google App Engine.

SaaS (Software as a Service)

SaaS is perfect for replacing legacy, on-premise software with ready-to-use cloud applications. There’s no need to install, patch, or maintain anything — everything runs in the cloud.

Example use case:

Moving from local email servers to Microsoft 365 or Google Workspace.

Read on: Cloud Computing in Software Development: Benefits & Use Cases

Phase 3: Planning and Strategy Development

Once you know your goals and chosen models, it’s time to create a migration roadmap. This plan should outline every detail of the move — from timelines and resources to risk mitigation and communication strategies.

Migration strategy types

Most organizations adopt one of the following migration approaches:

• Rehost (Lift and Shift): Move applications as they are to the cloud with minimal changes. Fast, but doesn’t leverage full cloud benefits.
• Refactor (Re-architect): Modify applications to use cloud-native features like auto-scaling and containers.
• Rebuild/Replace: Fully rebuild applications or replace them with SaaS alternatives.
• Hybrid: Combine on-premise and cloud for flexibility during transition.

Security and compliance planning

Security must be embedded from day one. You should define:

• Encryption standards
• Identity and access management (IAM)
• Backup and recovery policies
• Compliance with regulations (GDPR, ISO, HIPAA, etc.)

Partnering with experts

Migrating to the cloud is a complex process that touches every part of your IT ecosystem. Partnering with an experienced cloud migration company ensures best practices are followed, risks are minimized, and the migration is aligned with your business goals. A good partner can also assist with licensing, architecture design, and post-migration optimization.

Read on: The Real Cost Of Migrating Your Application Stack To The Cloud

Phase 4: Migration and Testing

This is where the real transformation begins. Depending on your chosen approach, the migration can be done in stages or all at once.

Data migration

Transferring data from on-premise systems to the cloud requires careful coordination to prevent downtime and data loss. Tools like Azure Migrate, AWS Migration Hub, or Google Transfer Service automate much of this process.

Key best practices:

• Backup everything before migration
• Test data integrity after transfer
• Use incremental sync for large databases

Application migration

Applications can be migrated as-is (lift and shift) or modernized using containers and microservices. Testing in a staging environment ensures everything performs as expected before go-live.

Validation and testing

Post-migration testing is crucial:

• Validate system performance and connectivity
• Confirm user access and authentication
• Monitor resource utilization and cost

Phase 5: Optimization and Continuous Improvement

Migration is not the end — it’s the beginning of continuous optimization.

Performance tuning

Use cloud monitoring tools (Azure Monitor, AWS CloudWatch, etc.) to track performance, latency, and resource usage. Adjust instance sizes, autoscaling rules, and caching strategies to optimize costs and efficiency.

Cost management

The beauty of the cloud lies in its pay-as-you-go model. Regularly review your resource consumption and remove unused services to maximize ROI. Tools like Azure Cost Management or AWS Cost Explorer can help you stay within budget.

Training and culture shift

Successful cloud adoption requires a shift in mindset. Invest in training your teams to understand cloud governance, DevOps principles, and security best practices. Encourage collaboration between IT, operations, and development teams.

Read on: How to Save 65% on Cloud Costs with Optimization

The Human Side of Cloud Migration

Beyond the technical benefits, cloud migration empowers people.

It frees IT staff from repetitive maintenance work and allows them to focus on innovation. Developers can build faster, operations teams can scale dynamically, and business leaders gain real-time insights through analytics and AI services.

Working with a trusted migration partner also means your team doesn’t walk this journey alone. Specialized firms bring experience from dozens of successful migrations — guiding you through challenges, ensuring compliance, and helping your company unlock the full potential of the cloud.

The Key Benefits of Moving to IaaS, PaaS, and SaaS

Cost Efficiency

• No more large upfront investments in servers or licenses.
• Pay only for what you use — a true “operational expense” (OpEx) model instead of “capital expense” (CapEx).
• Reduce maintenance, cooling, power, and space costs.

Scalability and Flexibility

• Scale resources up or down in seconds.
• Handle seasonal traffic or unexpected workloads without buying new hardware.
• Ideal for growing businesses and dynamic environments.

Improved Security and Compliance

• Leading cloud providers invest billions in cybersecurity and compliance certifications.
• Features like encryption, identity management, and continuous monitoring come built-in.
• You gain enterprise-grade protection with minimal internal effort.

Business Continuity and Disaster Recovery

• Cloud infrastructure provides built-in redundancy and backup options.
• Quick recovery in case of data loss or system failure.
• High availability (often 99.9%+ SLA) without expensive secondary data centers.

Faster Innovation and Deployment

• Teams can deploy applications in minutes instead of weeks.
• Automation tools (CI/CD pipelines, APIs) are native in most cloud platforms.
• Focus shifts from maintaining servers to building products that matter.

Global Reach and Accessibility

• Deploy applications close to your users anywhere in the world.
• Access resources securely from any location and device.
• Perfect for distributed or remote teams.

Environmental Sustainability

• Cloud data centers are optimized for energy efficiency and renewable energy use.
• Reducing on-prem hardware directly lowers your carbon footprint.

Ready to modernize your infrastructure and unlock the full potential of the cloud? This article highlights how shifting from on-premise systems to IaaS, PaaS, or SaaS can reduce costs, improve scalability, strengthen security, and accelerate innovation — all while freeing your teams to focus on what truly matters. Whether you’re looking to lift-and-shift, refactor, or fully reimagine your applications, the right cloud model can transform how your business operates. If you’d like expert guidance on assessing your environment or planning a seamless migration, get in touch with Rare Crew — we’re here to help you move forward with confidence.