Architecture economics
The Seam Tax
The Seam Tax is the recurring cost created when responsibility is split across platforms without clear ownership, contracts and operational control.
Where the tax appears
- Duplicate customer and interaction data
- Workflow rebuilt in more than one platform
- Fragile event and identity mapping
- Manual reconciliation after partial failure
- Separate reporting that never quite agrees
Why it grows
Each workaround makes the next change harder. Teams add more integration, more exception handling and more manual control because the underlying ownership decision remains unresolved.
How to reduce it
- Choose a system of record for each durable object
- Define event contracts and failure behaviour
- Give the integration product ownership and service levels
- Measure rework, delay and operational exceptions
- Remove duplicate workflow when platform ownership changes
Make the boundary explicit
A seam will always exist. The goal is to make it intentional, observable and economically justified.