AWS CDK vs Terraform vs Pulumi -- UK Infrastructure as Code (2026)

Updated: June 20269 min read
UKGBPComparisonUK GDPRUK Law

AWS CDK (TypeScript) is ClickMasters default for all UK regulated AWS infrastructure: same language as application code, CDK L3 constructs for reusable NHS DTAC and FCA PS21/3 compliance patterns, and the strongest CloudFormation change set audit trail for FCA PS21/3 change management. Terraform is right for multi-cloud or large existing Terraform codebases. Pulumi right when full programming language power is needed. IaC choice affects NHS DTAC Domain 3 infrastructure change audit trail, FCA PS21/3 IBS change management, and UK GDPR data residency enforcement.

FactorAWS CDK (TypeScript)Terraform (HCL)Pulumi (TypeScript)
NHS DTAC D3 infrastructure auditBEST -- CloudFormation change set per PR (reviewed, approved, applied)Terraform plan + apply -- PR-reviewablePulumi preview + up -- PR-reviewable
FCA PS21/3 change managementBEST -- CloudFormation change set = IBS change record, IBS-tagged resourcesTerraform state drift detectionPulumi state -- less mature audit trail
UK GDPR data residency enforcementBEST -- CDK Stack with eu-west-2 constraint -- compile-time enforcementHCL region = variable -- no compile-timeTypeScript -- can enforce via constructor
Shared types with application codeBEST -- TypeScript CDK uses same FHIR R4 and FCA typesHCL -- no shared typesBEST -- same TypeScript as app code
NHS DTAC L3 reusable constructsBEST -- ClickMasters NHS DTAC CDK Construct LibraryTerraform modules -- goodPulumi ComponentResource -- good
Multi-cloud supportAWS-only (CDK for Terraform is a workaround)BEST -- AWS, GCP, Azure, KubernetesBEST -- all cloud providers
UK developer talent poolBEST -- TypeScript CDK -- largest UK IaC community 2026Large -- historically dominantSmaller -- growing
Cost of drift detectionCloudFormation drift detection (native)BEST -- Terraform plan shows all driftPulumi refresh
ClickMasters defaultAll UK regulated AWS production infrastructureMulti-cloud, non-AWS, large Terraform estatesComplex IaC needing full programming constructs

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