Case Study: Reddit cuts infrastructure costs and simplifies migration with HashiCorp Terraform

How Reddit Conducted a Large-Scale Infrastructure Migration Using Terraform

Reddit worked with HashiCorp and its Terraform platform to solve a major infrastructure challenge: its data engineering team was manually managing AWS resources across regions and accounts, which created high operational overhead, security complexity, and expensive data transfer costs. As Reddit’s user base and data needs grew, the company needed a better way to inventory, standardize, and migrate its infrastructure while making it easier for other teams to use the same patterns.

Using HashiCorp Terraform, Reddit built reusable modules for foundational AWS infrastructure, Kafka, Zookeeper, and Kubernetes, then used them to migrate its data infrastructure from us-west-2 to us-east-1 with parallel pipelines and controlled traffic cutover. The result was significantly less manual work, a reduction of Kafka broker replacement from 14 steps to 3, broader internal reuse of infrastructure modules, and measurable savings of about 50% in data transfer costs and 40% in EC2 instance costs.

Reddit

Krishnan Chandra

Senior Software Engineer