2 min lesson
The DX tradeoff is part of the design
Take this situation: "In your JIT access design, why is replacing standing IAM permissions with just-in-time grants a reduction in blast radius rather than just a process change?" Lead with your decision, then add the reason.
Step 1 of 2
The DX tradeoff is part of the designFrictionless or it gets bypassed
If a JIT grant takes 20 minutes during an incident, engineers will keep a break-glass admin role - and now you have standing access anyway.
Design for sub-minute grants on the common path or the control gets routed around.
An approver-≠-requester step on production-data roles costs one click and stops self-service privilege escalation.
Auto-expiry costs nothing at use time and removes a whole class of forgotten-credential risk.
Say explicitly that the secure path has to be the easy path. A defense that engineers bypass under pressure is worse than none, because it gives false assurance. The senior move is to design the JIT flow so the fast way and the safe way are the same way - that's the builder-first, developer-empathy posture Cursor hires for, stated out loud.
Lead with boundaries, not controls. Open with “let me mark the trust boundaries first” and physically draw them before proposing a single mitigation. It signals you reason from the system's structure rather than reaching for a checklist and it gives the interviewer a map to push on. Then tie each control back to a specific boundary so nothing is a free-floating best practice.
Cross-check against the cloud-security and threat-modeling modules. If you stalled enumerating boundaries or couldn't justify a friction tradeoff, that's the gap to close before the onsite.