A founder framed this as a binary recently: hire security out entirely and stop thinking about it day to day, or invest in building at least a small amount of in-house security literacy on the team. Worth walking through what each choice actually trades away, because neither is free of a real cost, just different kinds.
What fully outsourcing actually buys you
Handing security entirely to an outside reviewer or firm means real, deep expertise applied to your app without your team needing to develop that expertise themselves, and it removes the temptation to grade your own homework that comes up constantly in this space. For a lot of small teams, this is a completely reasonable trade, especially early on, when building that expertise in-house would mean pulling focus from the product itself.
What it quietly gives up
An outside review is a point-in-time snapshot, and I've written about this limitation before. If nobody on your own team has any baseline literacy, no ability to recognize a gap between scheduled reviews, every mistake introduced in the gap sits there, undetected, until the next engagement happens to catch it. A team with zero in-house awareness has no early-warning system at all between reviews, only the review itself, however far apart those are scheduled.
What building even a small amount of in-house capability actually looks like
This doesn't mean hiring a dedicated security engineer, which is genuinely out of reach for most small teams. It means whoever's building the app knows the basic checklist from this blog well enough to run it themselves as a matter of habit: the cross-account test, the logged-out admin check, the key search. That's a modest amount of literacy, achievable without a security background, and it's the layer that actually catches something between outside reviews, rather than leaving that entire gap unguarded.
The actual recommendation
- Build the basic checklist habit in-house regardless of budget. It costs time, not money, and it's the layer that catches things continuously rather than only at scheduled intervals.
- Bring in outside expertise for anything genuinely complex, a deeper audit, business-logic review, anything beyond what the basic checklist can catch on its own.
- Don't treat these as competing options funded from the same limited budget. The in-house habit is nearly free. The outside expertise is what it costs to go deeper than that habit can reach alone.
Fully outsourcing without any in-house baseline leaves the gaps between engagements completely unwatched. Building a modest in-house habit without ever bringing in an outside perspective leaves you checking your own work with your own blind spots intact. The strongest setup, for any team that can manage it, uses both, not as alternatives to choose between, but as two different layers doing two different jobs.