I watched a client spend $800K building a custom analytics dashboard. It took eight months, consumed their best engineers, and delivered roughly 80% of what Looker offered out of the box for $30K per year. They built it because their VP of Engineering wanted to. Not because it was the right business decision.
This happens constantly. Engineering teams naturally prefer building over buying because building is more interesting, more resume-enhancing, and gives them more control. That instinct isn’t wrong — it’s just incomplete. Every build decision is a capital allocation decision, and it needs to be evaluated like one.
The Three Questions
Is this a differentiator or a commodity? If the capability you need is what makes your product unique — your recommendation algorithm, your proprietary data processing pipeline, your core workflow engine — you should probably build it. If it’s something every company needs and has nothing to do with your competitive advantage — authentication, payment processing, email delivery, analytics — you should probably buy.
The test I use: would your customers switch to a competitor because of this capability? If yes, build. If no, buy.
How quickly do you need it? Building takes 3-12x longer than buying, depending on complexity. If you need the capability in production within 6 weeks and building it would take 6 months, the buy decision is obvious regardless of long-term preference. Speed to market has real economic value that engineers often underweight.
What’s the 3-year total cost of ownership? This is where build-versus-buy analyses usually go wrong. Companies compare the build cost against the annual license fee and conclude that building is cheaper. But the build cost doesn’t include: ongoing maintenance (typically 15-25% of initial build cost per year), infrastructure costs, the cost of hiring and retaining engineers to maintain the system, and — most importantly — the opportunity cost of those engineers not building your actual product.
When you run the real math, buying is cheaper for commodity capabilities roughly 90% of the time.
When Building Makes Sense
Your core product. If you’re a fintech company, you should build your transaction processing engine. If you’re a healthcare platform, you should build your clinical workflow system. The thing that makes you you should live in your codebase.
When integration is the product. Sometimes the value isn’t in any individual capability but in how they’re connected. If your product’s unique value is an integrated experience that no combination of bought tools can replicate, building the integration layer (at minimum) is justified.
When the market doesn’t serve your need. This is rarer than engineers think, but it’s real. If you have genuinely unusual requirements — extreme performance constraints, novel data processing patterns, regulatory requirements that no vendor satisfies — building may be your only option.
When Buying Makes Sense
Identity and authentication. Use Auth0, Clerk, or your cloud provider’s identity service. Building your own auth is a security liability and a maintenance burden. The number of companies that have been breached through homegrown authentication systems is staggering.
Payment processing. Stripe, Adyen, or similar. Unless you’re building a payments company, this is not where your engineering time should go.
Monitoring and observability. Datadog, New Relic, Grafana Cloud. These companies employ hundreds of engineers to build monitoring tools. You will not build something better with a team of three.
Email and communication. SendGrid, Twilio, Customer.io. The deliverability problem alone takes years to solve well.
The Partner Option
Partnering — through APIs, white-label arrangements, or deep integrations — is the underused middle option. It makes sense when you need a capability that’s adjacent to your core product, when the integration quality matters to the user experience, and when neither building from scratch nor buying off-the-shelf gets you what you need.
I helped a healthcare client partner with a telemedicine platform rather than building video conferencing from scratch or buying a generic tool. The partner brought HIPAA-compliant video infrastructure and clinical workflow experience. My client brought the patient engagement platform and the user base. The integrated product was better than either company could have built alone, and it shipped in 8 weeks instead of 8 months.
The Decision Meeting
Here’s how I run build-versus-buy decisions with clients. Get engineering leadership, product leadership, and the CFO in the same room. Present three columns: build (with real cost, timeline, and ongoing maintenance estimate), buy (with total 3-year cost including implementation and integration), and partner (if applicable). Include opportunity cost in the build column — if those engineers spend 6 months building this, what features are you not shipping?
The conversation almost always converges once the opportunity cost is on the table. Engineers who wanted to build often agree that their time is better spent on the core product when the alternative cost is visible.
Related: Tech Debt Translation: Making Your CFO Care | AI Strategy for Non-Technical CEOs | The Prototype-to-Production Gap
