The Fundamental Question
Should you use Salesforce or build a custom CRM? Should you license an LMS or build your own? Should you use Shopify or build a custom e-commerce platform? The build vs buy decision affects every technology-dependent business — and getting it wrong costs years of lost productivity or hundreds of thousands in wasted development.
This guide gives you a practical, numbers-based framework to make the right decision for your specific situation.
When SaaS Wins
SaaS products win when your use case is standard, you're moving fast, and you don't have differentiated processes. Specific signals:
- Your process is commodity: Email marketing, project management, video conferencing, basic HR — there's no competitive advantage in building these. Use Mailchimp, Notion, Zoom, BambooHR.
- Speed is paramount: You can be live with Shopify in a day. A custom e-commerce platform takes 4–6 months minimum.
- Team is small: A 5-person startup doesn't have engineering bandwidth to build and maintain internal tools.
- Compliance is handled: Established SaaS products (HubSpot, Salesforce) have invested heavily in SOC 2, GDPR, and HIPAA certifications. You inherit that compliance posture.
When Custom Software Wins
Custom software wins when your processes are genuinely different from your competitors', when SaaS licensing becomes expensive at scale, or when integration complexity makes off-the-shelf solutions untenable.
- Your process IS your competitive advantage: Your pricing algorithm, your risk model, your supply chain logic — if competitors could replicate your process by buying the same SaaS, you don't have a moat. Custom software encodes your IP.
- SaaS costs scale badly: Salesforce Enterprise charges $300/user/month. At 100 users, that's $360,000/year — every year. A custom CRM built for $80,000 pays back in 3 months.
- You need deep integrations: If you need 15 legacy systems to talk to each other, no SaaS product will cover it cleanly. Custom middleware or a unified platform is the only option.
- Regulatory requirements are unique: IRDAI, RBI, DPDP Act, and sector-specific regulations often require data localisation and audit trails that SaaS products can't provide.
The Real Cost Comparison
Let's compare a CRM over 5 years for a 100-person sales team:
| Cost Item | Salesforce Enterprise | Custom CRM (Canny) |
|---|---|---|
| Year 1 | $360,000 (licences) | $75,000 (build) + $6,000 (hosting) |
| Year 2 | $360,000 | $24,000 (maintenance + hosting) |
| Year 3 | $396,000 (5% increase) | $24,000 |
| Year 4 | $415,800 | $30,000 (feature additions) |
| Year 5 | $436,590 | $30,000 |
| 5-year total | $1,968,390 | $189,000 |
The custom CRM costs 90% less over 5 years — and doesn't charge you more as you add users or data.
The Hybrid Approach
The best architectures often combine SaaS for commodity functions with custom software for differentiated processes. Examples:
- Use Stripe for payments (commodity) + custom CRM for complex sales workflows (proprietary)
- Use AWS infrastructure (commodity) + custom ML pipeline (proprietary)
- Use Shopify for checkout (battle-tested) + custom inventory/ERP integration (complex proprietary logic)
Decision Framework
Answer these five questions:
- Does an off-the-shelf product cover 80%+ of your exact use case without painful workarounds? → Buy
- Will your annual SaaS cost exceed $50,000 within 2 years? → Consider building
- Is the process you're automating a source of competitive advantage? → Build
- Do you have a technical team (or trusted development partner) to build and maintain the software? → Build feasible
- Are you in a regulated industry with specific data requirements a SaaS can't meet? → Build
If you answered "buy" to question 1 and "no" to questions 2–5, buy. If you answered "yes" to two or more of questions 2–5, build.