Fintech teams already live with a version of this discipline — it's usually called compliance, and it usually feels like overhead bolted onto engineering rather than something engineering does naturally. SpecDevShip's approval gates aren't a compliance feature, but they produce an artifact that compliance work needs anyway: a real, checkable record of what was reviewed and signed off on, and when.
Draft and approved as an actual audit trail
Every spec document's draft/approved status, combined with git history, produces exactly the kind of trail an audit or incident review asks for after the fact: what was the requirement, when was it approved, by implication of the commit history what changed and when, and — critically — was anything altered after approval without going back through review. That last question is usually the hardest one to answer honestly in a codebase without this discipline. Here, it's structurally impossible to answer "yes, silently."
Where full tier is almost always the right call
Payment processing, KYC/AML logic, anything touching account balances or transaction integrity — this is close to the canonical case for full tier's "data model change with real migration risk" and "new external system integration" criteria. The overhead of proper requirements, an architecture doc, and a task checklist is exactly proportionate to what's actually at stake in this category of change, which is precisely when the heavier path stops feeling like overhead.
Investigation discipline where a guessed fix is a liability, not just a bug
A financial-logic bug fixed on a plausible guess, without a cited, verified root cause, isn't just a quality problem — depending on what broke, it can be a reporting and disclosure problem. The Investigate skill's requirement to cite a cause by file and line, confirmed against real behavior rather than reasoned from code, produces exactly the artifact you'd want in hand if a regulator or auditor ever asked "how do you know what caused this, and how do you know the fix addressed it."
What this doesn't replace
To be clear: none of this is a substitute for your actual compliance program, your existing controls, or legal review of what regulatory requirements apply to your business. What it does is make your engineering process produce artifacts that make those conversations easier, instead of an engineering process that compliance has to work around.
For a fintech team already juggling real regulatory weight, a workflow that produces an honest paper trail as a side effect of how it normally works is worth more than one more dashboard telling you to write documentation you'll never get around to.