Comparison · Approach

Build custom,
or buy off the shelf?

The wrong answer is expensive in both directions — an unnecessary build, or a decade of licence fees for software your team quietly works around. Here is how to tell which side you are on.

Buy, when the process is standard

If thousands of companies do the thing identically and a mature vendor market exists — accounting, payroll, email, calendars — buy it. Building commodity software is the most reliable way to spend a year producing a worse version of something you could have licensed on a Tuesday.

Build, when the process is the business

Build when the workflow is the thing that makes you money, when per-seat licensing has started to compound faster than your growth, or when the software has forced the business to reshape itself around a vendor's assumptions.

Sentinel exists for exactly that reason. Multifamily operators were licensing five tools that did not talk to each other, then re-keying numbers between them. The licences were not the expense — the re-keying was.

The tell: look for the shadow system

You have already outgrown a tool when the team has quietly built a second one beside it.

  • Spreadsheets running alongside the software — the real system of record has moved, and you are paying a subscription for a filing cabinet.
  • The same number keyed into two places — that is an integration you are paying a salary to perform manually, every week, forever.
  • A documented workaround for a core task — when onboarding includes "here is how we get around this," the tool no longer fits the business.
  • Per-seat cost rising faster than headcount value — growth is being taxed by a licence rather than funded by it.

Two or more of these and the build case is usually already made — you are simply paying for it in hours instead of engineering.

The risk nobody quotes

The real failure mode of custom software is not cost or quality. It is abandonment: a build that ships, the team disperses, and within a year nobody can safely change it. That is why Zorm quotes the operation alongside the build. Unowned software is the liability — not the code.

Questions people ask

Should we build custom software or buy off the shelf?
Buy when the process is genuinely standard and the vendor market is mature — accounting, payroll, email. Build when the process is the differentiator, when you are paying per seat for software you have outgrown, or when the real cost has migrated into the spreadsheets and manual re-keying that surround the tool you already licence.
How do we know we have outgrown an off-the-shelf tool?
The clearest signal is the shadow system. When the team maintains spreadsheets beside the software, re-keys the same numbers between tools, or has a documented workaround for a core task, you are already paying for a custom system — just in salaried hours instead of engineering.
Is custom software more expensive?
Usually higher up front and often lower over three to five years, because per-seat licensing compounds as you grow while a build does not. The comparison that matters is total cost including the operation, not the build price against the first-year subscription.
What is the biggest risk in building?
Being abandoned with it. A build that ships and then has no owner becomes a liability within a year. This is why Zorm quotes the run alongside the build — unowned software is the actual failure mode, not the code.

Not sure whether to build?

Tell us the workflow and what you licence today. If buying is the right answer, that is the answer you will get.

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