Every founder eventually hits a version of the same question: do I build this software myself, or buy something off-the-shelf? Both instincts are strong and both are usually wrong.
The founders who default to building tell themselves they'll "have more control" and "save money over time." Most of them spend 3-6 months building a worse version of a $50/month SaaS product they could have subscribed to on day one.
The founders who default to buying tell themselves they're being "pragmatic" and "focusing on the core business." Some of them end up paying $2000/month for six overlapping SaaS subscriptions and stitching data between them with fragile CSV exports.
Neither instinct is a strategy. Here's the honest framework I use with founders to make this decision, plus the specific tests for when custom software actually pays off — and when it doesn't.
First: understand what you're comparing
Build vs Buy is not a technical decision. It's a business decision about where to invest your finite time and money.
When you "buy" (subscribe to SaaS or use off-the-shelf software), you get:
- Immediate access (usually within hours)
- Support included in the price
- Continuous improvements without any work from you
- Compliance and security someone else maintains
- Predictable monthly cost
When you "build" (custom software), you get:
- Exactly what you want (assuming you know what you want)
- No monthly subscription (but real hidden costs — see below)
- Full ownership of the code and data
- Ability to differentiate from competitors who use the same off-the-shelf tools
- The complete responsibility for keeping it working
The trap: comparing "$0/month for custom software I own" vs "$99/month for SaaS." That's not the real comparison. The real comparison is:
- Custom software cost: initial build ($10k-$150k+) + ongoing maintenance (~25% of build cost per year) + your time managing it + the cost of features you don't have that competitors do
- SaaS cost: monthly subscription + integration effort + workflow accommodation
Both have real costs. The question isn't "which is cheaper?" It's "which is cheaper AND more strategic for my specific situation?"
The core test: is this software your competitive advantage or your commodity infrastructure?
This is the single question that resolves 80% of build vs buy decisions.
Commodity infrastructure: software that every business in your category needs, that doesn't differentiate you from competitors. Email marketing. Accounting. CRM. Payment processing. Support ticketing. HR management.
Competitive advantage: software that IS your product, or that gives you a specific edge competitors don't have. If a restaurant's ordering system is generic, they compete on food. If a restaurant's ordering system uniquely handles their specific menu customization needs 5x better than competitors, that ordering system IS the competitive advantage.
The rule:
- Commodity infrastructure → almost always buy. Every hour you spend building your own accounting software is an hour you're not spending on your actual product. Even if you save $200/month on subscriptions, you've lost days of your own time — the most expensive thing in your business.
- Competitive advantage → seriously consider building. If the software IS your product, or is what makes your product better than alternatives, then buying it means you're competing on someone else's platform. That's often a losing position.
Most "should I build or buy?" questions turn out to be commodity infrastructure disguised as competitive advantage. Be honest about which category you're actually in.
The 6 questions that determine your answer
Once you've answered the commodity vs competitive-advantage question, run through these:
1. Does a good off-the-shelf option exist?
Sometimes founders decide to build because they haven't actually looked at what exists.
The exercise: spend 4 hours researching. Try 3-5 candidate products from your list. Sign up for trials. Actually use them for a task.
If you find something that solves 80%+ of your need at a reasonable price: buy it. The 20% you'd customize is almost never worth building a whole product for.
If nothing exists that solves even 50% of your need: building might actually make sense. But verify — often the reason nothing exists is that your need is unusual, and unusual needs often turn out to be workflow assumptions you could change instead.
2. Is your workflow standard or genuinely unique?
Standard workflow: you do things the way most similar businesses do them. Your accounting is normal accounting. Your CRM needs match what CRM products are built for. Your email marketing is email marketing.
Genuinely unique workflow: you do something meaningfully different that off-the-shelf tools can't accommodate without painful workarounds. Rare but real — usually driven by industry-specific regulation, an unusual customer type, or a genuine product innovation.
The test: describe your workflow to a person from your industry who's never worked with you. Can they immediately map it to standard tools? If yes, buy. If they say "hm, that's unusual," maybe build — but verify the unusual-ness is a strategic choice, not just accumulated habit.
3. What's the true 3-year cost of each option?
Do the math over 3 years, not 12 months.
SaaS example: $200/month × 36 months = $7,200. Plus 20-40 hours of integration and training. Total ~$8k-$10k.
Custom build example: $40k initial build + $10k/year maintenance × 3 years = $70k. Plus your time managing it (~50 hours/year × 3 = 150 hours of your time). Total closer to $80k-$100k.
Even at 10x higher cost, custom might still be right IF it's your competitive advantage. But if it's commodity infrastructure, the math is brutal — you're spending 10x for the same functional outcome.
Hidden costs founders underestimate for custom builds:
- Bug fixes (constant)
- Feature parity (customers will expect features SaaS competitors have)
- Security updates (never done)
- Regulatory changes (payment processing rules, tax rates, data privacy)
- Technical debt (accumulating faster than you notice)
- Original developer leaves (context loss = massive cost)
4. How stable is your understanding of the requirement?
Stable requirement: you know exactly what you need, it's not going to change much, and you understand the edge cases from experience.
Unstable requirement: you're still figuring out what you need. What you want in 6 months will probably be different from what you want today.
- Stable → buying makes sense (get something that solves the known problem)
- Stable AND custom → building makes sense (build the specific solution once)
- Unstable → BUY, don't build. Building the wrong custom software takes months to unwind. Switching between SaaS products takes days.
Founders who build too early usually do so BECAUSE the requirement is unstable — they think building will give them flexibility. It doesn't. It gives them a large asset that's built for the wrong version of the problem.
5. Do you have (or will you have) the team to maintain it?
Custom software has an ongoing cost that gets ignored during the "should we build?" decision: you need someone who can maintain it.
- Bug fixes when things break
- Updates when dependencies change or vulnerabilities are found
- New features when your business evolves
- Documentation as you hire new people who need to understand it
If you don't have this team, and can't afford to hire one, don't build. You'll end up with software you can't maintain and can't get anyone to touch, which is worse than paying a SaaS subscription forever.
The specific test: would you be willing to sign a 3-year contract for one senior developer at $100k+/year to maintain what you're building? If not, you can't afford the true cost of building.
6. What happens if the vendor dies?
For every SaaS you subscribe to, there's a risk: what if they get acquired, raise prices 5x, discontinue the product, or go out of business?
Mitigating factors:
- The vendor is profitable and public (unlikely to disappear)
- The data is portable (you can export and move)
- Multiple competing alternatives exist (you can switch)
- Your integration is loose (you're not deeply dependent)
High-risk situations for buying:
- Small vendor, unclear business model (might disappear)
- Data is proprietary and hard to export (you're trapped)
- Only one competent alternative (they can charge whatever they want when you're locked in)
- Deep integration into your workflow (switching means re-doing weeks of work)
If the vendor risk is high AND the software matters to your business, building starts to look better. But this is a smaller factor than the first 5 questions — most SaaS vendors are stable enough for the risk to be manageable.
The decision tree
Putting it together:
Is this software your competitive advantage?
├── NO → BUY.
│ (Don't waste your time building commodity infrastructure.)
│
└── YES → Does a good off-the-shelf option exist?
├── YES → Buy it, extend it with API/webhooks if you need custom bits.
│ (Extending a mature product is 10x cheaper than building from scratch.)
│
└── NO → Is your workflow genuinely unique?
├── NO → You're probably just being non-standard. Change YOUR workflow
│ to match a good product, not the other way around.
│
└── YES → Do you have (or will you have) the team to maintain?
├── NO → Buy, even if imperfect. Custom you can't maintain is worse.
│
└── YES → What's the 3-year cost of each option?
├── SaaS is <5x cost of custom → Buy.
│ (Every 1x in cost saved by building is easily lost in
│ time to build + opportunity cost)
└── SaaS is >5x cost of custom → Build. (Rare)The hybrid approach most founders miss
The build vs buy decision is often presented as binary. In practice, the highest-ROI answer is usually a hybrid:
Buy the commodity infrastructure. Build the differentiator that sits on top of it.
Example: a restaurant chain in Saudi Arabia I worked with was tempted to build a full custom ordering system from scratch. Instead, we used Salla (buy) for the commodity ordering + payments + inventory, and built a small custom module (build) for their unique multi-branch loyalty program that Salla didn't support.
- Built module: ~20,000 SAR
- Salla subscription: ~5,000 SAR/year
- Total year 1: ~25,000 SAR
The "full custom" quote they'd received: 350,000 SAR to build, ~80,000 SAR/year to maintain. The hybrid was 15x cheaper AND shipped in 3 weeks instead of 6 months.
The pattern: identify the specific 10-20% of functionality that's your differentiator. Buy the other 80% off the shelf. Build only the differentiator, and use APIs to connect it to what you bought.
This requires more strategic clarity than "build everything" — you have to actually name what's differentiating vs commodity. But it's almost always the right answer.
Common build-vs-buy traps
Trap 1: The vendor pitch that becomes a build recommendation.
Some consultants and dev shops will look at any problem and recommend building custom software. That's how they get paid. Get a second opinion from someone who doesn't profit from the outcome (a peer founder, an advisor, or an independent consultant who charges hourly not by project).
Trap 2: "We'll build it once and then it's free forever."
No software is free forever. Every custom system requires ongoing maintenance, updates, security patches, and feature additions. The idea that you build once and stop paying is a fantasy.
Trap 3: "The subscription is too expensive."
A $500/month subscription feels expensive. Building the equivalent yourself for $50,000 upfront + $15,000/year to maintain feels like "saving money." Do the math: SaaS pays for itself for 8+ years before it matches the build cost. Almost no founder needs a specific software feature to remain unchanged for 8 years.
Trap 4: "The SaaS almost does what we need — let's build our own version."
The word "almost" is doing violent work in that sentence. If SaaS does 80% of what you need, the 20% delta is almost never worth building a full alternative. Extend, integrate, or accommodate — don't rebuild.
Trap 5: Building because you enjoy building.
Technical founders sometimes build because it's fun, not because it's strategic. If you're building software your business doesn't strategically need because you personally enjoy the coding, be honest with yourself. That's a hobby, not a business decision.
What to do this week
Identify the software decision you're currently facing (the one that made you read this post). Write down the specific need in one sentence.
Run through the 6 questions above. Write down the answers. Don't skip any.
Do the 4-hour research exercise. Even if you're leaning toward building, spend 4 hours seriously evaluating what exists. Often you'll find something that's 80% right for 5% of the cost of building.
Get one outside opinion. Not from the vendor selling to you. From a peer, an advisor, or an independent consultant.
Consider the hybrid approach. Even if you decide to build, ask: what's the smallest piece I can build that only handles the differentiating 10-20%, buying the commodity 80% off the shelf?
If you're considering custom software but don't yet know the realistic scope of the build, the free MVP planner tool on this site will give you a first-draft estimate of what a proper build would look like. And if you're evaluating whether to hire a freelancer, an agency, or an in-house developer to do the build, the vendor decision tree is the prior question. If you decide to buy, the software contract clauses guide applies to SaaS agreements too, not just custom builds.
The founders who make this call well aren't the ones with the best technical instincts. They're the ones who separate "what makes my business different" from "what every business needs" — and only build the first.
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If you're staring at a specific build vs buy decision and want an independent read on which way to go, reach out via the contact page with a paragraph about the need and what you've already looked at. I'll spend 30 minutes on it and tell you what I'd do in your position — no bias toward either option.