SST Ion vs Pulumi vs AWS CDK: Best Infrastructure as Code 2026

Infrastructure as code is no longer optional. Every serious engineering team defines their cloud resources in version-controlled files, reviews infrastructure changes in pull requests, and deploys through automated pipelines. The debate has moved past "should we use IaC?" to "which IaC tool gives us the best balance of speed, safety, and developer experience?"

Three tools dominate the TypeScript and general-purpose IaC landscape in 2026: SST Ion, Pulumi, and AWS CDK. They share a surface-level similarity (write real code, deploy cloud resources) but differ dramatically in architecture, cloud support, state management, and pricing. Picking the wrong one costs you months of migration work and real money.

We have deployed infrastructure with all three across 200+ client projects. This guide gives you our honest, opinionated take on when each tool shines and when it falls flat. If you are evaluating IaC tools for a new project or considering a migration, this is the breakdown you need.

The biggest differences between these tools are hidden under the hood. Understanding the engine each tool uses to provision resources explains most of its strengths and limitations.

SST Ion: Terraform Providers with TypeScript Sugar

SST Ion (the successor to SST v2, which used CDK under the hood) made a radical architectural pivot. It dropped AWS CloudFormation entirely and rebuilt on top of Pulumi's engine and Terraform providers. The result is a tool that uses the massive Terraform provider ecosystem for resource provisioning but wraps it in a clean, opinionated TypeScript API designed specifically for serverless and full-stack applications on AWS.

SST Ion is not trying to be a general-purpose IaC tool. It is purpose-built for teams deploying Next.js, Remix, Astro, or API-based applications to AWS. It provides high-level components like Function, Cron, Queue, Bucket, and StaticSite that abstract away dozens of underlying AWS resources. A single NextjsSite component, for example, provisions a Lambda function, CloudFront distribution, S3 bucket, IAM roles, and route configurations automatically.

Pulumi: Real Languages, Any Cloud

Pulumi takes a fundamentally different approach. It is a general-purpose IaC platform that supports TypeScript, Python, Go, C#, Java, and YAML. Resources are defined using native programming constructs (loops, conditionals, classes, functions) and provisioned through Pulumi's own providers, which cover AWS, Azure, GCP, Kubernetes, Cloudflare, and hundreds of other services.

Pulumi's engine maintains a state file (stored in Pulumi Cloud, S3, or locally) and performs a diff against your desired state on every deployment. There is no intermediate compilation step like CloudFormation. Pulumi talks directly to cloud APIs, which means faster deployments and more accurate error messages when something fails.

AWS CDK: CloudFormation, But Make It TypeScript

AWS CDK (Cloud Development Kit) is Amazon's answer to the verbosity of raw CloudFormation templates. You write TypeScript (or Python, Java, C#, Go), and CDK "synthesizes" your code into a CloudFormation template, which is then deployed through the CloudFormation service. This means CDK inherits both the strengths and weaknesses of CloudFormation: rock-solid AWS integration, excellent drift detection, but painfully slow deployments and cryptic error messages when stacks fail.

CDK's L2 and L3 constructs provide sensible defaults for common patterns. An ApplicationLoadBalancedFargateService construct, for instance, provisions an ALB, ECS service, task definition, security groups, and auto-scaling in a single call. The construct library is mature and well-documented.

Architecture matters, but developer experience is what determines whether your team ships infrastructure changes confidently or dreads every deployment. Here is where the three tools diverge the most.

SST Ion: Live Lambda Dev Changes Everything

SST Ion's killer feature is Live Lambda Development. When you run sst dev, SST sets up a WebSocket connection between your local machine and AWS. Your Lambda functions execute locally with full access to deployed cloud resources (DynamoDB tables, S3 buckets, SQS queues). Change a function, save the file, and it runs in under a second. No redeployment. No waiting.

This is a game-changer for serverless development. Traditional workflows require you to deploy, wait 30 to 90 seconds, test, find a bug, fix it, deploy again, and repeat. SST's dev mode turns that into a near-instant feedback loop. For teams building Lambda-based APIs, this alone justifies choosing SST.

SST's CLI is also exceptionally clean. Commands like sst deploy, sst dev, sst remove, and sst secret set cover 90% of what you need. The SST Console (a web dashboard) gives you visibility into functions, logs, and issues across environments.

Pulumi: Preview, Up, and Real IDE Support

Pulumi's DX revolves around pulumi preview and pulumi up. Preview shows you exactly what will change before you deploy: resources created, updated, or destroyed, with a detailed diff. This is similar to terraform plan but with the full power of a programming language behind it. Pulumi's error messages reference your source code directly, not some intermediate template.

Because Pulumi uses real programming languages, you get full IDE support: autocompletion, type checking, inline documentation, refactoring tools. You can write unit tests for your infrastructure using standard testing frameworks (Jest, pytest, Go test). You can create reusable components as classes or functions and share them across projects via package managers (npm, pip, Go modules).

CDK: Synth, Deploy, Wait, Debug CloudFormation

CDK's workflow is cdk synth (generate CloudFormation), cdk diff (preview changes), and cdk deploy (push to CloudFormation). The synth step is fast, but CloudFormation deployments are notoriously slow. A simple Lambda function change can take 60 to 120 seconds. A VPC or RDS change can take 10 to 20 minutes. When a deployment fails, the error comes from CloudFormation, not your TypeScript code, and debugging often means digging through CloudFormation events in the AWS Console.

CDK does offer cdk watch for hot-swapping Lambda code and Docker images, which speeds up development. But it is limited compared to SST's Live Lambda Dev and does not work for most resource types. If you have worked with CDK on a large project, you know the pain of waiting for CloudFormation rollbacks after a failed deployment.

If your team deploys to more than one cloud provider, or even if you just want the option, this is where the three tools diverge sharply.

Pulumi: The Clear Multi-Cloud Winner

Pulumi supports over 150 providers: AWS, Azure, GCP, Kubernetes, Cloudflare, Datadog, PagerDuty, GitHub, Vercel, and more. You can provision an AWS RDS database, a Cloudflare DNS record, and a Datadog monitor in the same program. For enterprises running workloads across multiple clouds, or teams that use best-of-breed services from different providers, Pulumi is the only serious option among these three.

Pulumi's provider ecosystem is also growing faster than its competitors. Community providers and bridged Terraform providers mean that if a Terraform provider exists for a service, Pulumi can usually use it too. This is a massive advantage for teams integrating with niche or newer cloud services.

SST Ion: AWS-Focused, But That Is the Point

SST Ion is designed for AWS. While its underlying Pulumi engine technically supports other clouds, SST's high-level components (NextjsSite, Function, Queue, Cron) are AWS-specific. You can drop down to raw Pulumi or Terraform resources for other providers, but you lose SST's opinionated DX when you do.

For most startups, this is fine. AWS has the broadest service catalog, the largest market share, and the most mature serverless platform. If you are building on AWS and plan to stay on AWS, SST's focused approach means less configuration and faster shipping. If you need Cloudflare Workers or GCP BigQuery alongside your AWS infrastructure, look at Pulumi instead.

CDK: AWS Only, Full Stop

AWS CDK deploys to AWS through CloudFormation. That is it. Amazon released CDK for Terraform (CDKTF) as a separate tool that generates Terraform HCL, but it has a different API, a different community, and a different set of trade-offs. If you need multi-cloud, CDK is not the answer.

Where CDK does shine in the ecosystem is AWS construct libraries. The community has published thousands of L3 constructs on Construct Hub covering patterns like serverless APIs, data pipelines, and container services. If your architecture is 100% AWS and your team likes the construct model, CDK has the deepest library of pre-built AWS patterns. For a deeper look at setting up CI/CD pipelines alongside your IaC tool, we cover that in a separate guide.

Every IaC tool needs to track what resources currently exist so it can compute diffs on the next deployment. How each tool handles state has real implications for team collaboration, security, and disaster recovery.

SST Ion: Managed State with Passphrase Encryption

SST Ion stores state in an S3 bucket in your AWS account, encrypted with a passphrase you set during initialization. State is scoped per app and per stage (dev, staging, production), so team members can work on different stages without conflicts. The SST Console provides a visual layer on top of this state, showing deployed resources, function logs, and environment variables.

This approach is simple and works well for small to mid-sized teams. You do not need a separate state management service, and your state stays in your own AWS account. The downside is that you lose some collaboration features (state locking, audit logs, RBAC on state access) that managed platforms like Pulumi Cloud provide.

Pulumi: Flexible State Backends with Enterprise Features

Pulumi offers the most flexibility in state management. You can store state in Pulumi Cloud (their managed service), an S3 bucket, Azure Blob Storage, Google Cloud Storage, or a local file. Pulumi Cloud adds state locking, audit logs, RBAC, drift detection, secrets management, and a web dashboard with deployment history.

For teams, Pulumi Cloud's collaboration features are excellent. You can see who deployed what, when, and what changed. Stack references let one project consume outputs from another (your networking stack exports VPC IDs that your application stack imports). The policy-as-code engine (CrossGuard) lets platform teams enforce rules like "no public S3 buckets" or "all Lambda functions must have a timeout under 30 seconds."

CDK: CloudFormation Is Your State

CDK delegates state management entirely to CloudFormation. Every CDK stack maps to a CloudFormation stack, and CloudFormation tracks the state of every resource. This means you get drift detection for free (CloudFormation can detect when someone manually changes a resource) and you never need to worry about state file corruption or storage.

The downside is that CloudFormation stacks are scoped to a single AWS account and region. Cross-account and cross-region deployments require CDK Pipelines or a custom CI/CD setup. CloudFormation also has hard limits: 500 resources per stack, 200 outputs, 60 parameters. Large applications need to be split across multiple stacks, which adds complexity to your dependency graph.

IaC tools are free to use locally, but the collaboration features, dashboards, and managed services that make them practical for teams all have price tags. Here is what each tool actually costs when you factor in team usage.

SST Console: Free Tier + $20/Seat/Month

SST's CLI is open source and free. The SST Console, which provides function logs, resource visualization, and issue tracking, has a free tier for personal use and costs $20 per seat per month for teams. This is reasonable for what you get, especially since the Console integrates directly with your deployed SST apps and provides features like log tailing, secret management, and environment overviews that would otherwise require multiple AWS Console tabs.

Pulumi Cloud: Free Individual + $50/Seat/Month for Teams

Pulumi's CLI is open source. Pulumi Cloud's Individual tier is free and includes 200 resources, unlimited deployments, and basic secrets management. The Team tier is $50 per seat per month and adds RBAC, audit logs, deployment history, and policy enforcement. The Enterprise tier (custom pricing) adds SAML SSO, self-hosted options, and dedicated support.

At $50/seat/month, Pulumi is the most expensive option for teams. For a 10-person engineering team, that is $500/month (or $6,000/year) just for the IaC collaboration layer. You can avoid this cost by using a self-managed backend (S3 + DynamoDB for state locking), but you lose the dashboard, audit logs, and RBAC features that justify the price. If you are watching cloud costs closely, this is worth considering carefully.

AWS CDK: Free (But You Pay in Time)

CDK is completely free. There is no paid tier, no managed service, no dashboard subscription. CloudFormation is free too (you pay only for the AWS resources you provision). This makes CDK the cheapest option in terms of direct tooling costs.

The hidden cost of CDK is developer time. Slower deployment cycles, more verbose code, harder debugging, and more complex CI/CD pipelines all translate to hours of engineering time per week. A senior engineer spending an extra 2 hours per week fighting CloudFormation deployments costs far more than $50/month in Pulumi Cloud fees. The "free" tool is only free if your team's time has no value.

Cost Comparison Table

• SST Ion: $0 CLI + $0 to $20/seat/month (Console). 10-person team: $200/month.
• Pulumi: $0 CLI + $0 to $50/seat/month (Cloud). 10-person team: $500/month.
• AWS CDK: $0 everything. 10-person team: $0/month direct cost, higher indirect cost in engineering time.

Migrating between IaC tools is painful but sometimes necessary. Here is what each migration path looks like in practice.

CDK to SST Ion

This is the most common migration we see. Teams that started with CDK hit the wall of slow CloudFormation deployments and limited dev tooling, then discover SST's Live Lambda Dev and want to switch. SST Ion supports importing existing AWS resources, so you can gradually move resources from CloudFormation to SST-managed state without destroying and recreating them. The SST team has published migration guides specifically for CDK users, and the process typically takes 1 to 3 weeks for a medium-sized project.

CDK to Pulumi

Pulumi provides a pulumi import command that can import existing AWS resources (including those managed by CloudFormation) into Pulumi state. They also offer a CDK-on-Pulumi adapter (pulumi-cdk) that lets you use CDK constructs inside Pulumi programs, giving you a gradual migration path. This is a solid option for teams that want to keep their existing CDK constructs while gaining Pulumi's multi-cloud support and faster deployments.

SST v2 to SST Ion

If you are on SST v2 (which used CDK under the hood), upgrading to SST Ion is a significant rewrite. The component APIs are different, the state backend changed from CloudFormation to Terraform/Pulumi, and the configuration format is new. SST provides a migration guide, but plan for 1 to 2 weeks of focused work for a typical serverless application.

Pulumi to SST Ion (or Vice Versa)

Since SST Ion uses Pulumi's engine under the hood, there is some conceptual overlap. But SST's high-level components do not map 1:1 to raw Pulumi resources, so migration in either direction requires rewriting your infrastructure definitions. Export your resource IDs, import them into the new tool, and verify the state matches before decommissioning the old setup.

After deploying with all three tools across dozens of client projects, here is our opinionated recommendation.

Pick SST Ion If You Are a Startup Building on AWS

If you are deploying a full-stack application (Next.js, Remix, Astro, or a serverless API) to AWS, SST Ion is the best choice in 2026. Live Lambda Dev alone saves hours per week. The high-level components mean less code and fewer foot-guns. The SST Console gives you visibility without a $50/seat/month price tag. The trade-off is that you are locked into AWS and SST's opinionated component model, but for most startups shipping fast on AWS, that is exactly what you want.

Pick Pulumi If You Need Multi-Cloud or Enterprise Features

If your organization runs workloads across AWS, Azure, and GCP, or if you need enterprise governance features like policy-as-code, RBAC, and audit logs, Pulumi is the right tool. It is also the best choice for platform engineering teams building internal developer platforms, where you need to create reusable infrastructure components that other teams consume. The cost is higher, but the flexibility and governance features justify it at scale. For teams evaluating hosting platforms alongside their IaC setup, Pulumi's multi-provider support integrates well with hybrid deployment strategies.

Pick CDK Only If Corporate Policy Requires It

We will be direct: CDK is the weakest option in 2026 for new projects. The CloudFormation bottleneck is real, the developer experience lags behind SST and Pulumi, and the AWS-only limitation is the same as SST but without SST's superior DX. The only scenarios where CDK makes sense are when your organization has mandated CloudFormation for compliance reasons, when you have a large existing CDK codebase that would be expensive to migrate, or when your platform team has deep CDK expertise and no appetite for change.

The Bottom Line

Infrastructure as code tooling has matured significantly. You no longer need to write YAML or JSON templates to manage cloud resources. All three tools let you use real programming languages, but SST Ion and Pulumi deliver meaningfully better developer experiences than CDK for the majority of use cases.

If you are starting a new project today on AWS, start with SST Ion. If you outgrow it or need multi-cloud, Pulumi is a natural next step. If you are already on CDK, evaluate whether the migration cost to SST or Pulumi is worth the developer experience gains (in most cases, it is).

Need help choosing the right IaC tool for your project or migrating from one to another? Book a free strategy call and we will map out the best infrastructure approach for your team, stack, and growth stage.