Not sure if this is aligned with what you are asking for, but... in major engineering projects, the biggest constraints I’ve seen come from the intersection of scope, safety, and integration. The technical work is rarely the problem, it’s the regulatory timelines, supply-chain dependencies, and cross-discipline coordination that create real pressure. You’re constantly balancing design changes, long-lead materials, stakeholder approvals, and risk controls without slowing the project down. The key is tight alignment between engineering, construction, vendors, and governance so these constraints surface early instead of becoming last-minute blockers.