Opentofu vs pulumi, which one survives a 200-account landing zone

IaC tools built for single-team deployments fail structurally at 200 accounts because the failure modes are architectural, not configurational. Why 200 Accounts Is Where IaC Tools Break IaC tools built for single-team deployments fail structurally at 200 accounts because the failure modes are architectural, not configurational. Scale Threshold State Management Provider Auth Overhead Execution Time Impact ~10 accounts One backend bucket, one workspace; quirks are routable Not a meaningful bottleneck Sequential plan/apply is manageable ~50 accounts Sequential execution still viable; blast radius contained Per-account latency exists but tolerable Below threshold where parallelism is required 200+ accounts 200 separate plan operations per shared-module refactor 3-sec per-account auth × 200 = 10 min added per plan cycle Sequential Terraform applies measured at 4.1 hours end-to-end A 10-account environment forgives sloppy state management. One backend bucket, one workspace convention, one pipeline. Engineers learn the tool's quirks and route around them. At 200 accounts, those same quirks compound. Why the threshold is 200 State lock contention, cross-account provider authentication chains, and module resolution latency stack on top of each other. The result is not slower deploys. It is non-deterministic deploys, which is operationally worse. The specific threshold matters. Below roughly 50 accounts, most teams run plan and apply sequentially without parallelism because the blast radius of a runaway apply is contained. Above 200 accounts, sequential execution becomes untenable. We measured a 200-account org where sequential Terraform applies across all accounts took 4.1 hours end-to-end. That latency made emergency remediation impossible inside a standard incident window. Three compounding failure modes State file proliferation. Each account carries its own state file, and each state file is a consistency boundary. At 200 accounts, a single refactor touching a shared modu