What it is
The Low-Code Build-vs-Buy Decision Guide is a practical framework for deciding, before you commit budget and headcount, when to buy packaged SaaS, when to build on a low-code platform like OutSystems or Power Apps, and when to write custom code. It reframes the choice away from a ladder you climb only when you outgrow the last rung and toward three genuinely different bets, each best for a different kind of problem. The guide provides a decision matrix scoring all three options across nine criteria, a 'build on low-code when' checklist, a set of pressure-test questions, and a frank list of the hidden low-code costs to budget for.
The three options are clearly drawn. Buy means licensing packaged SaaS — a CRM, a help desk, an HRIS — that already does roughly 80% of the job. Build on low-code means assembling the app yourself on a visual platform (OutSystems, Mendix, Microsoft Power Apps, Appian, or Retool), where you gain speed and a managed runtime but trade away some control. Custom-code means engineers writing the app from scratch with full ownership and no platform fees beyond infrastructure. The guide's central argument is to pick by fit, not by reflex.
The fit rules are specific. Buying wins when the need is common and non-differentiating. Low-code wins when the workflow is specific to how you operate but is not your competitive moat, and you need it in weeks not quarters. Custom wins when the app itself is the differentiation, must scale hard, or has constraints no platform will satisfy. The pressure-test questions then surface the traps — whether the missing 20% is worth building at all, whether the app is something you would ever sell, what it looks like at 10x volume in five years, who maintains it after launch, and how hard it would be to leave the platform.
What it's used for
Teams use this guide to make a defensible build-versus-buy call before money is committed, and specifically to know when low-code is the right tool rather than a reflexive middle ground. It is most valuable at the start of an internal-app decision, when the cost of choosing wrong is highest.
- ✓ Scoring a specific app against the nine-criterion decision matrix — from how common the problem is, to time to first release, to five-year total cost, to scale ceilings and exit portability — to see which of buy, low-code, or custom actually fits.
- ✓ Confirming low-code is the right path using the checklist: the workflow is specific to how you operate, you need it live in weeks, business users can own the logic with IT governing the platform, requirements keep changing, and the app orchestrates existing systems rather than inventing core tech.
- ✓ Pressure-testing the decision against the questions that expose hidden risk — whether the missing 20% above a SaaS product is worth building anything, whether the app is competitive IP, what happens at 10x volume in five years, who maintains it, and how hard the platform is to leave.
- ✓ Budgeting honestly for hidden low-code costs: platform and per-app or per-user licensing that climbs with adoption, vendor lock-in that makes apps hard to port off OutSystems, Mendix, or Power Apps without a rebuild, governance overhead to prevent citizen-built sprawl, and scaling ceilings on records, concurrency, and APIs.
- ✓ Avoiding the lock-in trap of building competitive differentiation on a platform you cannot leave, by routing genuine IP toward custom code instead.
- ✓ Distinguishing a real gap from a request that an existing app, spreadsheet, or SaaS tool already covers, so you do not build a whole app for a 20% gap.
- ✓ Giving finance and leadership a structured, criterion-by-criterion rationale for the chosen path rather than a gut call.
Who uses it
The guide is used by the people who decide where internal apps get built and who will pay for them. It is most useful before a platform commitment, when the team is weighing options rather than defending a choice already made.
Context & good to know
The most expensive build-versus-buy mistakes come from treating the three options as a maturity ladder rather than distinct bets. Teams reflexively reach for custom code because it feels serious, or for low-code because it is the new default, without asking whether the problem is even theirs to solve. This guide's core move — pick by fit, not by reflex — exists to interrupt that reflex with explicit criteria, because the right answer is sometimes simply to buy SaaS and configure the gap.
Low-code's sweet spot is narrow but real: a workflow specific to how you operate, needed fast, owned by business users with IT governing the platform, orchestrating existing systems rather than inventing core technology, and operationally important but not the product you sell. The danger zone is building competitive differentiation on a platform you cannot easily leave — OutSystems, Mendix, and Power Apps apps rarely port to another vendor or to open code without a rebuild. The pressure-test questions about IP, five-year scale, and exit are designed to keep teams out of that zone.
Hidden costs are where low-code decisions most often go wrong after the fact. Licensing climbs with adoption rather than staying flat; success itself can push an app into record, concurrency, or API limits that force a costly re-platform exactly when it is delivering most; and ungoverned citizen building creates a sprawl that demands governance overhead the original business case never counted. This guide pairs naturally with a governance policy and a build-on-low-code checklist, and it points directly at the comparison work — features, pricing, and verified reviews for OutSystems, Mendix, Power Apps, Appian, and more at spotsaas.com — that turns a 'low-code' decision into a specific platform choice.