Field note
Draw trust boundaries before you ship the next feature
When product pressure rises, teams often extend an existing service with a new endpoint and postpone the harder question: which principals should ever be allowed to reach it. Softgategrid engagements begin with that question because trust boundaries age faster than feature lists.
A useful boundary map names the actors (users, jobs, partner systems), the channels they use, and the data classes that cross those channels. Without that map, rate limits and WAFs become theatre around an open interior.
In United Kingdom regulated contexts, the map also clarifies which flows need stronger evidence of control. That is not paperwork for its own sake; it keeps remediation focused when an auditor or customer security questionnaire arrives.
If your next release adds a privileged admin action, pause long enough to write the boundary. The architecture review we run treats that pause as engineering work, not a compliance afterthought.