Infrastructure as Code

Setting up a research cluster or a production trading server by manually clicking through a cloud console works fine the first time, but it's nearly impossible to reproduce exactly, hard to audit, and easy to accidentally drift out of sync between "what's running" and "what anyone documented." Infrastructure as code (IaC) replaces the clicking with declarative configuration files — written in tools like Terraform, AWS CloudFormation, or Pulumi — that describe the desired end state of the infrastructure: which servers, with what specs, on which network, with what permissions.

The config files live in the same version control system as the trading code itself, so every change to the infrastructure is a reviewable diff with a commit history, exactly like a code change. Applying the config brings the real infrastructure into line with what's declared — spinning up what's missing, tearing down what's no longer listed — and running it twice in a row does nothing the second time, since nothing has changed (a property called idempotency).

For a quant team, this matters most for reproducibility: a research environment that produced a backtest six months ago can be recreated byte-for-byte from the same config, a disaster-recovery failover to a new region is a config apply rather than a week of manual rebuilding, and a new hire's laptop or cloud dev environment can be provisioned identically to everyone else's with one command instead of a checklist that's always slightly out of date.