Cloud migration: on-premise vs cloud

⸻ Beyond Energy

Senior Cloud Engineer Graeme Stirling examines the shift from on-premise to cloud and its impact on costs and agility.

Cloud migrations spark strong opinions in the tech world. Some champion the reliability and control of on-premise solutions, while others swear by the agility and scalability of a cloud-first approach. Both approaches serve important purposes, and gaining insight into their development and specific strengths enables organisations to choose the best fit for their needs.

A look back: the dawn of data centres

In the early days, companies essentially had two options for their infrastructure: On-premise or Co-location.

On-premise meant owning and managing everything such as hardware, racks, power, networking, and cooling within your own data centre.
Co-location took some of these responsibilities off the customer’s plate but came at a premium. However, it offered greater flexibility by placing your data in a nearby facility that met key data centre requirements within a shared location

Enter the hyperscalers

The arrival of cloud hyperscalers dramatically changed the landscape. These massive providers built extensive data centres worldwide, often pushing the limits of local power availability – especially in regions like the USA. Instead of dedicating hardware to a single customer, cloud providers embraced a shared-resource model across many users.

This shift has driven rapid migration from on-premise to the cloud, enabling organisations to transition from Capital Expenditure (CapEx) models to more flexible Operational Expenditure (OpEx) models.

CapEx vs OpEx

Traditional on-premise deployments require heavy upfront investments, including building data centres, purchasing hardware, and provisioning all necessary infrastructure before a service goes live. This creates a high barrier to entry and often results in long lead times when scaling or upgrading.

In contrast, the cloud offers much lower barriers to entry. Scaling cloud instances up or out can happen within minutes, sometimes automatically, thanks to auto-scaling groups and monitoring tools. You only pay for the resources you actually use, which enhances both flexibility and cost efficiency.

Characteristics and challenges

Agility in the Cloud

Cloud platforms don’t just offer scalable resources – they foster agility:

Hardware refresh: Unlike on-premise applications locked to specific hardware, cloud apps can migrate seamlessly to newer, optimised hardware types as providers innovate.
Rapid prototyping: Launch, test, and tear down entire environments quickly. This accelerates development cycles and reduces costs by only paying for resources when needed.
Infrastructure as Code (IaC): Tools like Terraform enable teams to define infrastructure through code. This ensures testing environments closely mirror production, supporting consistent deployments and easier scaling. Principal Engineer Edwin Lizarazo touches on this in his blog, highlighting these benefits and more.

Why stay on-premise?

There remain compelling reasons to stick with on-premise solutions, primarily for industries with strict regulatory requirements. Owning dedicated hardware within your own data centres can simplify compliance, despite the increased management and cost overhead.

Cloud providers are addressing this with offerings like AWS Dedicated Hosts, which give users dedicated physical servers within the cloud, bridging some gaps between the models.

Modernising for the cloud

Migrating applications to the cloud presents a valuable opportunity to evaluate your current software and its suitability for cloud environments. Legacy monolithic applications can be challenging to transition directly, making this a good time to consider modernisation efforts. These may include updating the existing system, replacing it with a newer solution, or moving to a Software as a Service (SaaS) provider. Each option involves significant decisions that require careful planning and thoughtful preparation before moving forward.

Lift and shift: when modernisation isn’t an option

When modernisation isn’t a viable option, migrating applications from on-premise to the cloud using a “lift and shift” approach can be the most practical solution. This is often driven by factors such as legacy hardware reaching end-of-life or falling out of vendor support, prompting a reassessment of how the application is delivered.

In such cases, a cutover migration allows the application to be moved as-is to newly provisioned cloud infrastructure. These migrations must be carefully planned in advance. Maintenance windows should be clearly communicated to all relevant teams, and steps such as taking final snapshots, transferring data to the cloud, and restoring it on the new environment must be executed with precision. Planning for DNS cutovers is also essential to ensure a smooth transition and minimal disruption for end users.

Communication is key

Successful migration starts with clear communication:

Effective communication is vital: Informed users are supportive users. Keeping teams and customers updated about migration timelines, planned outages, and restoration helps set clear expectations and reduces frustration.
Avoid overwhelming support channels: When users know what to expect, customer service desks can focus on critical issues instead of managing confusion.
Build trust through transparency: Open communication fosters positive sentiment toward migration teams and future changes.

Final thoughts

Building and managing your own data centre or even renting space in one is costly and time-consuming. Cloud migration offers a compelling alternative, especially when hardware refreshes loom.

With consumption-based pricing, rapid provisioning, and continuous innovation, the cloud lets teams focus on delivering value rather than managing infrastructure. Internal or customer-facing applications alike can benefit from the speed, agility, and cost-efficiency the cloud provides.

By embracing modern cloud practices, organisations unlock a foundation for agility, collaboration, and operational excellence. To stay informed with tech insights like these and explore how Hypercube’s cloud solutions can support your transformation, check out our Cloud Offerings.