What are the pros and cons of public cloud?

The public cloud refers to computing services offered by third-party providers over the internet, rather than owning and maintaining your own computing infrastructure. Public cloud services are attractive to many companies because they offer potential cost savings, scalability, and flexibility. However, there are also some downsides to consider when weighing the decision to move to the public cloud. This article will examine the key pros and cons of public cloud to help you determine if it’s the right choice for your business.

Pros of Public Cloud

Cost Savings

One of the biggest potential advantages of public cloud is cost savings. With public cloud, you pay only for the resources you use without having to purchase, install and maintain your own hardware and data centers. This can significantly reduce your capital expenditures. Additionally, if your resource needs change over time, you can scale up or down to match demand, rather than being stuck with unused on-premises capacity.

Public cloud providers can offer lower costs because they benefit from economies of scale across their many customers. The three largest public cloud providers – Amazon Web Services (AWS), Microsoft Azure and Google Cloud Platform – pass some of those savings on to customers.

However, cost savings aren’t guaranteed with public cloud. You still need to optimize your cloud usage and carefully right-size your deployments to match demand. Unchecked cloud spending can quickly surpass the costs of on-premises infrastructure.

Scalability and Flexibility

The on-demand nature of public cloud makes it easier to scale your IT resources up or down to meet fluctuations in demand. If you experience a usage spike, you can instantly add more capacity without having to purchase and install new servers. When demand decreases again, you can reduce capacity and stop paying for those extra resources.

This scalability gives you more flexibility to experiment. For example, you could launch a test environment, carry out your experiments and then decommission it, paying only for the time it was in use. You couldn’t feasibly do this with on-premises hardware.

Faster Innovation

With public cloud, you don’t need to build and maintain your own infrastructure. This frees up your IT teams to focus less on maintenance and more on innovation that delivers value for the business.

Public cloud providers also release hundreds of new features and services each year. This gives you faster access to new technologies like artificial intelligence, Internet of Things, serverless computing and more to build innovative applications.

Increased Reliability

Leading public cloud providers offer very high service level agreements (SLAs), averaging 99.9% uptime for compute services. They can provide this level of reliability because they operate enormous global networks of data centers and servers.

Unless you are able to make a massive investment in redundant infrastructure, it is difficult to match the reliability of the major cloud platforms on-premises.

Improved Disaster Recovery

Using public cloud can greatly enhance your ability to recover from outages or disasters. Cloud providers operate geographically distributed data centers that you can leverage to store backup copies of your data and applications.

If one region experiences an outage, you can quickly spin up your systems in another region with minimal downtime. Creating this level of redundancy with an on-premises footprint would be very expensive and complex.

Cons of Public Cloud

Data Security Concerns

Placing your data and applications in the public cloud means you are trusting a third-party provider with that data. While cloud providers implement robust security controls, many organizations are still uneasy about giving up full control.

Data breaches can and do happen even with major cloud platforms. If your data is especially sensitive, you may prefer to keep it within your firewalls.

Compliance Risks

Along with security concerns, using public cloud can potentially expose you to compliance risks. Your company may be subject to industry or government regulations that impose restrictions on how data is managed. Storing regulated data in the public cloud may not align with compliance requirements.

Cloud providers need to adhere to standards like SOC 2 and ISO 27001, but that doesn’t guarantee compliance for your specific regulatory obligations. You are still responsible for ensuring compliance even when using public cloud.

Vendor Lock-In

Public cloud vendors offer proprietary services and technologies that may not be interoperable with other clouds. Once you build systems around a particular cloud platform, it can be difficult and costly to migrate them to a different provider.

This potential for vendor lock-in is a risk to consider, especially for large-scale, mission-critical systems where portability is important.

Loss of Control

When you move systems to the public cloud, you cede some control to the cloud provider. You rely on their capabilities to ensure adequate security, performance, availability and governance. This loss of control can be disconcerting for some organizations.

You must implement strong cloud management practices including monitoring, automation and governance models to ensure visibility and control in the public cloud.

Network Connectivity Dependence

Public clouds are accessed over the public internet. This makes you dependent on your network connectivity for availability and performance. If you experience an internet outage or network latency, it could significantly impact cloud-based systems.

Cloud providers give you options to use direct dedicated connections instead of the internet. But network dependence is still a factor to consider.

When to Choose Public Cloud

Here are some key factors that make public cloud a strong choice:

  • You have variable or unpredictable demand
  • You need rapid innovation and take advantage of new technologies
  • You want to avoid large capital expenditures
  • You need geographic diversity for disaster recovery
  • You are a small or mid-sized business without dedicated IT resources

When to Avoid Public Cloud

Here are some factors that may make public cloud less ideal:

  • You handle highly sensitive data with strict security/compliance needs
  • You need absolute control over performance and availability
  • You have very steady, predictable infrastructure needs
  • You have specialized legacy systems that won’t work in public cloud
  • You are unable to invest in cloud management best practices

Hybrid Cloud

Rather than choosing between public cloud and on-premises, many organizations use a mix of both known as hybrid cloud. You can maintain proprietary systems on-premises while also taking advantage of public cloud benefits where it makes sense.

A well-designed hybrid architecture gives you the best of both worlds—control plus agility. You can employ a cloud bursting model where your core systems run on-premises but can burst into the public cloud to scale out for traffic spikes.

Many public clouds now offer hybrid capabilities to seamlessly connect your on-premises infrastructure. This simplifies deployment of hybrid architectures.


Using services from multiple public clouds is referred to as a multi-cloud strategy. This provides benefits like:

  • Avoidance of vendor lock-in
  • Taking advantage of unique services from different providers
  • Isolation of fault domains

But it also adds management complexity of monitoring and controlling multiple cloud environments. A management platform can help provide a unified view and minimize this complexity.

Decision Criteria

When deciding whether to choose public cloud, private cloud or hybrid/multi-cloud, it’s helpful to consider factors like:

Criteria Public Cloud Private Cloud
Cost Pay-as-you-go avoids capital expenditure You own the infrastructure so full capex cost
Agility and speed Instantly tap into cloud provider’s vast capacity Adding capacity requires your own procurement/deployment
Scalability Auto-scale based on demand spikes and valleys Limited by on-prem infrastructure size
Security and compliance Depends on provider’s controls; shared security Fully within your control behind firewall

Looking at these trade-offs will help you determine the right cloud strategy for your specific requirements.


Public cloud offers compelling benefits like cost savings, scalability, reliability and innovation. But you also need to weigh cons such as reduced control, security risks and vendor lock-in.

The optimal approach for most organizations is a hybrid model that uses public cloud for suitable workloads while maintaining core systems on-premises. With proper cloud management practices, you can maximize the benefits of public cloud while minimizing the downsides.