Security issues discovered late in delivery are expensive, disruptive and difficult to remediate. Despite this, many digital services still treat security assurance as a final hurdle rather than an integral part of design.

Threat modelling and architecture assurance allow organisations to identify realistic attack scenarios early, when mitigations are cheaper and easier to implement. By understanding trust boundaries, data flows and attack paths upfront, teams can make informed design decisions rather than relying on compensating controls later.

For regulated environments, this approach also supports clearer risk ownership. Decisions are documented, residual risks are visible, and go‑live approvals are based on evidence rather than assumptions.

Key takeaway:

Security added late slows delivery; security designed early enables it.