Thynkr Systems
What Is Infrastructure as Code — and Why Does It Matter for Your Development Team?
There is a version of cloud infrastructure management that most development teams are quietly familiar with — the one where environments drift apart over time because each was created by hand, where 'it works on staging'
Custom Software Development
3 min read
There is a version of cloud infrastructure management that most development teams are quietly familiar with — the one where environments drift apart over time because each was created by hand, where 'it works on staging' failures happen because staging was configured differently from production three months ago by someone who has since left, and where disaster recovery is limited by the fact that nobody quite knows how the production environment was set up.
Infrastructure as Code is the practice that eliminates most of this. It is not a new idea — the principle of defining infrastructure declaratively rather than configuring it manually has been around since at least the early 2000s — but the cloud has made it both significantly more powerful and significantly more accessible.What infrastructure as code actually means
Infrastructure as Code (IaC) means representing your infrastructure — servers, networks, databases, storage, security groups, DNS records, load balancers — as configuration files in a version-controlled repository, rather than as a set of manual steps performed in a cloud console or terminal.
Instead of logging into the AWS console, clicking through the interface to create a VPC, then creating subnets, then an EC2 instance, then a security group — all steps that exist only in the cloud provider's records and your memory — you write a configuration file that describes the desired end state. Running that file creates or updates the infrastructure to match the description. The file is the infrastructure, and it lives in your code repository alongside your application code.The concrete benefits
Reproducibility is the most immediate benefit. An environment defined as code can be created identically as many times as needed — development environments that match production, staging environments that are not one manual-configuration-decision away from drifting, disaster recovery environments that can be stood up in minutes rather than days.
Version control means infrastructure changes are audited. Every change to the infrastructure configuration is a commit with an author, a timestamp, and a message. The question 'who changed the production security group to allow inbound traffic on port 22?' has a clear answer when the infrastructure is in a repository. Before IaC, that question could be unanswerable.
Code review for infrastructure changes. If your database configuration, your network topology, and your security group rules are all code, they can be reviewed by a second engineer before being applied, using the same pull request process used for application code. This is one of the most effective ways to catch infrastructure security issues before they reach production.The main tools: Terraform, Pulumi, and native options
Terraform by HashiCorp is the most widely adopted IaC tool and supports all three major cloud providers with the same declarative syntax. Its state management model — tracking what it has deployed and reconciling configuration with actual cloud state — is powerful but requires careful management, particularly in team environments where multiple people may be making changes.
Pulumi allows infrastructure to be defined in general-purpose programming languages (Python, TypeScript, Go) rather than a domain-specific language like Terraform's HCL. For teams that find the DSL limiting or want to share code between application and infrastructure layers, Pulumi is a compelling alternative.
AWS CloudFormation and Azure ARM Templates are provider-specific native IaC tools. They offer deep integration with their respective providers but create vendor lock-in and have historically been considered more verbose and less ergonomic than Terraform.How to start if your team isn't there yet
The most practical starting point for teams new to IaC is not to attempt to codify your entire existing infrastructure immediately. That path leads to a large, complex migration project that competes with other priorities and frequently stalls. Instead, apply IaC to new infrastructure as you create it. The next new environment you build, build it with Terraform. The next new service you deploy, define its infrastructure as code. Over time, the proportion of your infrastructure that is managed as code grows, and the benefits accumulate.ThynkrSystems implements infrastructure as code as a standard part of all cloud engagements. If you're moving to the cloud or modernising your infrastructure management, we will set you up with IaC practices that your team can actually maintain and build on.