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CAST AI vs. Zesty: Which One Is Better for Cutting Your Cloud Costs?

After years of unimpeded growth, teams are looking to cut expenses quickly in the face of a downturn. This shift calls for proper tooling and processes – and that’s where AI and automation can deliver great results.

A zesty toy with a cloud on it.

Zesty started as a storage optimization solution and has since transitioned to cost reduction via committed resource buy-back with an element of rightsizing.

While similar to CAST AI in broad strokes, Zesty offers a limited approach to cloud cost management based on reserved capacity buy-back that only works on AWS. Read our comparison to find out which one will be more suitable for your team.


CAST AI automates cloud infrastructure management for Kubernetes and cuts your compute bill by an average of 65%.

The platform works on all three major cloud providers and features autoscaling, rightsizing, spot instance automation, full-fledged cost monitoring, and security insights all in one place. It is the ultimate choice for an engineer looking to save time and control costs in one go.

About Zesty

Zesty, originally a storage optimization tool, now has a reserved cloud capacity buy-back feature with an added element of rightsizing.

The product promises fast results and reduced reserved capacity management burden but can only help teams operating in AWS. The approach doesn’t solve the root cause of high costs in the long term, especially in cloud-native organizations.

CAST AI vs. Zesty – quick feature comparison

FeatureCAST AI 🥇Zesty
Supported platforms
Google Cloud Platform
Microsoft Azure
Cost allocation and visibility
Detailed cost allocation
Automated cost forecasting
Advanced cost reporting
Cost view across multi-cloud
Cost optimization and automation
Automated rightsizing
Node autoscaling
Reserved Instances
AI-driven instance selection
Automated pod scaling parameters
Automatic bin packing
Cluster scheduling
Spot instance automation

Detailed comparison of Zesty and CAST AI

  1. Installation and setup
  2. Cost allocation and visibility
  3. Cost optimization and automation
  4. Security
  5. Pricing
  6. Summary

1. Installation and setup

CAST AI is fast to start on your own. After creating an account, you can connect your Kubernetes cluster and get free cost optimization recommendations within minutes. To do so, you will need to connect your cluster.

Once you complete this step, you will get a detailed comparison of your current and recommended cloud resources within minutes. Then, if you’re happy with the results, you can implement them automatically – the platform guides you through all the required steps.

Supported cloud providers: CAST AI supports AWS, Google Cloud Platform, and Microsoft Azure.

Zesty’s freemium version of Commitment Manager lets you quickly check potential savings on your EC2 consumption. The provider promises to deliver insights on possible savings within 5 minutes and without installing additional software.

Nonetheless, Zesty will ask for permission to access your AWS Cost Explorer account. Once connected, it will scan your infrastructure needs in real time and adjusts your commitments accordingly, finding the most attractive discounts in the AWS marketplace. You’ll also need to register to the RI marketplace or connect to an existing account.

Supported cloud providers: Zesty supports only AWS Reserved Instances.

2. Cost allocation and visibility

CAST AI cost monitoring features provide complete, real-time visibility into the provisioning and cost of your resources across different cloud providers. You can track expenses down to individual microservices before seeing the total cost of the cluster. The platform works with the three major service providers and offers cross-cloud visibility thanks to universal metrics and Prometheus integration.

Cost allocation in CAST AI is available per cluster, node, namespace, workload, and label. You can divide expenses into project, cluster, namespace, and deployment levels. The historical cost report lets you understand how your cluster expenses fluctuated over time, the normalized cost per provisioned and requested CPU, and how much you’ll have to pay at the end of the month.

Zesty also provides an overview of your expenses, but due to its focus on Reserved Instances, its scope of reporting is far narrower. It improves visibility only over your EC2 instances.

Zesty’s dashboard mainly presents RI-related insights, including on-demand compute cost, effective EC2 cost, daily compute cost, and average commitment coverage. It also lets you view how your expenses changed over time and the projection of costs and usage for the end of the month.

3. Cost optimization and automation

Although both CAST AI and Zesty depend on AI and automation to reduce cloud costs, they use them very differently.

CAST AI: a complete range of cloud cost optimization methods

CAST AI analyzes your workload’s needs in real time and picks the most appropriate mix of methods from the following:

Automated rightsizing with AI-driven instance selection

CAST AI’s algorithms select the optimal instance types and sizes to match your workload’s needs at a fraction of the cost. When more nodes are needed, the platform’s engine picks instances that guarantee the required performance at the lowest price – all of this happens automatically.

Selecting the same instance shape for every node in a cluster can lead to overprovisioning, so CAST AI includes multi-shape cluster creation. As a result, you get an optimal combination of different instance types in line with your application’s needs.


CAST AI includes an autoscaler that uses business metrics to generate the optimal number of required pod instances. The feature then scales the replica count of your pods up and down.

If there is no work to be done, it eventually scales to zero, eliminating all pods. CAST AI also guarantees that the number of nodes in use always suits the application’s requirements, autonomously scaling nodes up and down.

Cluster scheduling and termination

CAST AI allows you to stop and resume clusters created within the platform automatically.

Automatic bin packing

Kubernetes distributes applications equally across a cluster without regard for how cost-effective this setup is, which often proves challenging.

CAST AI modifies the default pod scheduling behavior and uses automatic bin-packing to reduce waste according to your set preferences. As a result, fewer nodes bring greater savings – without any engineer lifting a finger.

Spot instance automation

Spot instances can be even 90% cheaper than on-demand instances, but you need automation to avoid potential interruption when your provider pulls the plug.

CAST AI fully automates the process of replacing spot instances, so you don’t have to worry about your workloads not having a place to run. The platform always looks for better instance alternatives and provisions instances in a split second to guarantee high availability.

And if there happens to be no spot available, CAST AI’s spot fallback will temporarily schedule affected pods to on-demand nodes.

Zesty: automatic adjustment of Amazon RIs to your app’s needs

Once connected, Zesty’s algorithm starts collecting data on your Amazon EC2 usage patterns to train the prediction model. Simultaneously, the platform analyzes the prices of RIs on the marketplace to spot the most lucrative deals.

Equipped with this data, Zesty promises to predict how many cloud resources like CPUs or hard drives your workload may need at any given time. Informed by these projections, the platform takes nearly real-time actions like purchasing and selling public cloud instances without human intervention.

Zesty automatically picks the optimal instance type and size when adding new resources. Subsequently, the platform manages EC2 commitments in real time and without manual tasks for your team – reducing costs by up to 60%.

Zesty seems capable of boosting your cloud resource management for companies already using Reserved Instances. However, while quickly relieving the issue of soaring cloud bills, the tool doesn’t address its root cause – cloud waste – as comprehensively as CAST AI.

4. Security

Created by cybersecurity industry veterans, CAST AI is both ISO 27001 and SOC 2 certified. Unsurprisingly, it has several security features, such as encryption at rest/in transit, secrets management, network security, logging, visibility, and more. The platform doesn’t access sensitive environment variables like secrets, passwords, tokens, etc.

Besides, CAST AI provides automatic patching and upgrades to VMs and K8s, eliminating the chance of error in your clusters. The platform’s most recent container security feature analyzes, prioritizes, and reports on your cluster configuration and vulnerability issues.

Authentication in Zesty is based on the AWS Identity and Account Management (IAM) cross-account role for which an external ID will need to provide factor-two authentication. The platform doesn’t store private keys, passwords, or authentication tokens.

5. Pricing

CAST AI users can start by examining how much they can save thanks to optimizing their cloud infrastructure. The free account provides access to the savings report but also free cost monitoring and container security insights.

If you want to implement the recommendations automatically, you must choose one of the three options: Growth, Growth PRO, and Enterprise. Each plan follows a transparent pricing model based on your use of compute resources, not the reserved resources or the percent of savings it helps you get. That’s why there is no need for prepayment or forecasts.

Zesty’s Commitment Manager also provides users with a quick way to discover potential savings thanks to its free visibility and monitoring tool.

Automation features unlocking potential savings on EC2 instances require a premium subscription – and here, Zesty offers just one success-based option. The platform’s fee is 25% of the savings it helped generate. In addition, the provider offers higher discounts and premium support to users choosing its annual subscription.

Summary – CAST AI vs. Zesty for reducing your cloud expenses

Both Zesty and CAST AI deploy automation to deliver tangible savings and streamline cloud operations, but they do it differently.

While Zesty helps to reduce bills for AWS users, it lacks a more comprehensive approach to cloud cost management that includes multiple cloud provider compatibility and visibility of cloud costs. As a result, it mainly deals with the symptoms instead of solving the root cause once and for all.

On the other hand, CAST AI’s rich selection of automation features delivers cost and time savings to any cloud-native organization. The platform offers the same convenient workflow for large organizations operating on multiple clouds and easy onboarding valued by businesses looking for immediate cost savings.

To see what results CAST AI can bring you, register and start with a free savings report.

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