Using terraform_remote_state to reference another team's outputs works, but creates a tight coupling that breaks when they change their state — what's the alternative?

terraform_remote_state creates a direct, structural dependency on another team's state file's exact internal shape — any output rename, backend migration, or even just restricting read access to that state breaks your configuration with no interface contract in between. A more decoupled alternative is having the producing team publish specific values through a dedicated mechanism designed for cross-team sharing (SSM Parameter Store, Secrets Manager parameters, or a dedicated "outputs" data source specifically designed as a stable interface) rather than reading their raw state directly — this creates an explicit, versioned contract instead of an implicit dependency on internal implementation details.

terraform_remote_state reads another configuration's entire state, not just a defined interface: the data source pulls the full state file's outputs, meaning your configuration is coupled to whatever that other team's state actually contains, structured however they happen to have structured it — there's no formal contract; it's directly reading their internal implementation detail (their state file), not something explicitly published as a stable external interface.

Any change to the producing team's state genuinely breaks your configuration, often without warning: if they rename an output, restructure their state (splitting one state file into several), or migrate to a different backend, your terraform_remote_state reference breaks — and importantly, they may have no idea your configuration depends on their state at all, meaning they have no reason to consider your dependency before making a change that's entirely reasonable from their own perspective.

Publishing values through a dedicated, explicit sharing mechanism creates a real interface contract: having the producing team's Terraform configuration write specific, deliberately-published values to SSM Parameter Store (or Secrets Manager, or a similar service designed for this) — and having consuming configurations read from that parameter store rather than the raw state — means the "interface" is an explicit, intentional publication, not an accidental byproduct of however their state happens to be structured internally.

This decoupling means the producing team can freely restructure their own state without breaking consumers: since consumers read from the published parameter (a stable, deliberately-maintained value), the producing team can split their state file, rename internal resources, migrate backends — any of these internal implementation changes — without needing to coordinate with every consumer, as long as they keep publishing the same parameter values consumers actually depend on.

This mirrors a broader software-architecture principle: terraform_remote_state is analogous to directly reading another service's internal database rather than calling its published API — convenient short-term, but creates exactly the kind of tight coupling that breaks encapsulation and makes independent evolution of each side difficult, which is why a genuine "publish an interface" pattern is generally the more maintainable long-term choice for cross-team Terraform dependencies specifically.

• terraform_remote_state couples your configuration directly to another team's state file's exact internal structure, not to any deliberate, stable interface.
• Any change to the producing team's state (renamed outputs, restructured state, backend migration) can break consumers, often without the producing team even knowing a dependency exists.
• Publishing specific values through a dedicated mechanism (SSM Parameter Store, Secrets Manager) creates an explicit, intentional interface contract instead.
• This decoupling lets the producing team freely evolve their own state's internal structure without needing to coordinate with every consumer, as long as the published interface values remain stable.

• Terraform: terraform_remote_state Data Source
• AWS: Systems Manager Parameter Store