I’ve seen a pattern that keeps showing up when I review institutional onchain architectures.
The instinct, especially for teams coming from a traditional SaaS background, is to layer privacy and compliance as separate services on top of an otherwise transparent stack. Access control in one service, audit logging in another, sanctions screening through a third-party API, travel rule data handled at the application layer.
The failure mode is predictable. When a regulator asks to reconstruct what happened in a specific transaction, the answer requires correlating logs across multiple systems with different data models and different timestamp resolutions. The compliance evidence exists, but assembling it under audit pressure is a manual exercise.
The architectural alternative worth thinking about is collapsing access control, disclosure, sanctions screening, travel rule, and audit logging into the same proxy layer that mediates every RPC call. Each request gets processed through all five in sequence. The audit trail is structurally coherent because all five share the same request context.
For engineering leads designing this layer in 2026, it's worth deciding early whether the architecture stays unified or fragments.