Guide
When should a business build custom software instead of buying SaaS?
Most software decisions should be “buy”. Off-the-shelf SaaS is faster and cheaper for common needs. But there's a line past which buying starts costing you more than building — in workarounds, per-seat fees, and lost differentiation. Here's how to tell which side of the line you're on.
By Miguel Alejandro Hayes· Founder, Hayes Projects· with Claude (AI)
Default to buying
If a mature tool already does what you need — email, accounting, basic CRM, scheduling — buy it. You get maintenance, security, and updates for a predictable fee, and you're not tying up capital in something that isn't your core business.
Building custom software to replicate a commodity tool is almost always a mistake. The question isn't “could we build it?” — it's “is this specific enough to us that no tool fits?”
Signs it's time to build
Consider custom when: you're paying for several tools plus the manual work of gluing them together; your team lives in spreadsheets because no product matches your process; per-seat SaaS costs scale painfully as you grow; or the workflow is a genuine competitive advantage you don't want to hand to a generic tool every competitor also uses.
The strongest signal is repeated manual work that exists only because your tools don't talk to each other. That gap is exactly what custom software closes — and it compounds in value every day the tool is used.
You don't have to choose all-or-nothing
The best answer is often hybrid: keep buying commodity SaaS, and build the thin custom layer that connects them and encodes your specific process. A configurator on top of your catalog, an integration that syncs your CRM and accounting, a portal that gives clients exactly what they need — small, high-leverage custom pieces around tools you already pay for.
That's how we approach it: build what's differentiating, integrate the rest.
An honest note: I wrote this with AI’s help. I used it to organize the research and tighten the prose, then reviewed, corrected and signed off on every line myself. Which is, more or less, the whole point: AI speeds up the draft — the judgment and the responsibility stay mine.
Frequently asked
Isn't building always riskier than buying?
+
Building carries risk, which is why we start with a short paid validation phase and ship a lean MVP before committing to a full build. Buying has its own hidden risk: outgrowing a tool and being locked into its limits.
What's the cheapest way to test a custom idea?
+
Build the smallest version that solves one real workflow, put it in front of users, and expand from what you learn. A focused MVP ships to production first and grows from there — the timeline follows the scope, which we define up front.
About the author
Miguel Alejandro Hayes — Founder, Hayes Projects
Economist and essayist turned developer. He founded Hayes Projects, a Miami venture studio and custom software lab, to build software that ships, scales and solves real problems.
Meet the founder→Co-author (AI)
Claude — Anthropic’s AI assistant
Anthropic’s AI model. It helped organize the research, structure the draft and tighten the prose. Every claim was verified and signed off by a human.
Not sure which side of the line you're on? Tell us your workflow and we'll give you a straight answer — build, buy, or hybrid.
Talk it through →Prefer email?
Leave your email and we'll reach out with an idea for your case.
No obligation. No spam — just one useful, concrete reply.
We use first- and third-party cookies (Google Analytics and Google Ads) to measure traffic and improve the site. You can accept or reject them. Learn more