Deploying Serverless Functions Across Regions with AWS Lambda
Part 2 of the multi-region serverless series: getting the same Lambda deployed to several AWS regions and keeping it that way. Infrastructure-as-code with provider aliases, a CI/CD pipeline that ships to every region, and versions plus aliases for safe rollouts.
This is the second part of the "Going Global with Serverless" series. The first part laid out the whole picture. This one zooms in on one job: deploying a Lambda function to more than one region and keeping those deployments identical. You do it for lower latency, better availability, data-residency rules, and plain redundancy, but the hard part is not the first deploy. It's making sure region two never drifts from region one.
The article works through three strategies. First, infrastructure-as-code so every region gets provisioned the same way, with a Terraform example that uses provider aliases to define the function once and target multiple regions. Second, CI/CD to remove the manual step, shown as a GitHub Actions workflow that deploys to us-east-1 and eu-west-1 on every change. Third, Lambda versioning and aliases (via the AWS CLI) so you can publish a version, point an alias at it, and roll forward or back without editing the function itself. The running example is a travel booking platform that routes users to their nearest region and fails over when one goes down.
Key takeaways
- Multi-region only works automated: manual deploys drift, and drift bites during failover; IaC plus a fan-out pipeline is the whole game
- Publish versions and move an alias, don't mutate the function: a
prodalias on a numbered version gives clean rollback and canary hooks - Pick one IaC tool and stick with it across regions; article shows Terraform provider aliases, skips SAM/CDK/Serverless and per-region env config and layers
Who this is for
Developers and architects who already run serverless in one region and are being asked to go multi-region. Assumes you know Lambda, and are at least comfortable reading Terraform and a GitHub Actions workflow. Read part 1 of the series first for the context.
The full walkthrough, with the Terraform, the Actions workflow, and the CLI commands, is on DEV.to.