The buy vs build debate in ISV product teams is as old as commercial software itself. But here’s what’s changed in 2026: the cost of the wrong decision just went up dramatically.
Your product roadmap is a battlefield. Every feature request, every competitive gap, every “quick win” from sales triggers the same conversation. Should we build this ourselves or embed something that already exists?
Agentic tools like Claude Code tend to form a strong build temptation. Custom modules that used to take months or years can now be done in days or weeks. Just because you can build a quick v1 doesn’t mean you should. Many ISVs get this wrong because they’re asking the wrong questions. The upfront cost and development time are only part of the story. The real decision factors are buried deeper, and they’ll determine whether you’re still competitive in 18 months.
Let me walk you through the factors that matter.
The core competency filter
Before you discuss cost or timeline, ask yourself one brutal question: does this feature represent our core intellectual property?
If the answer is no, you’re probably building something you should buy.
If you’re a vertical SaaS platform for healthcare providers, your core competency is understanding healthcare workflows, compliance requirements, and clinical user behavior. Building your own payment processing engine? That’s not core. That’s distraction dressed up as control.
The core competency filter works like this: draw a line between features that differentiate your product in the market and features that simply make your product viable. Differentiation gets built in-house. Viability gets sourced externally.
Many ISVs rationalize building non-core features because “we can do it better” or “we need more control.” Your engineering team might be talented enough to build a better email delivery system than SendGrid. But should they? Absolutely not.
The opportunity cost is staggering. Every day your senior engineers spend building commodity features is a day they’re not spending on the features that win deals and build your IP.
The hidden iceberg of maintenance and evolutions (the real trap)
Product managers love to say “we can build this faster than we can evaluate, negotiate, and integrate a vendor solution.” Sometimes that’s true for a basic v1, especially leveraging AI.
But here’s the trap: you’re not only comparing build-time to integration-time. You’re comparing build-time plus all future iterations to integration-time plus all future upgrades.
Underneath the surface sits years of maintenance, bug fixes, security patches, performance optimization, API version upgrades, compliance updates, and an ever-expanding feature scope. That “simple” custom integration you built in Q2 2025? By Q4 2026, it consumed 3x the original development hours in maintenance alone.
Vendor solutions evolve. Good ones ship new features that allow you to keep up with competition. They respond to market demands across hundreds of customers. They hire specialists who do nothing but think about that one problem space.
When you build, you get exactly what you spec out. When you buy, you get continuous improvement (assuming you picked the right vendor).
At MediaDev we talk to dozens of ISVs every month who go through this. An ISV builds a custom analytics dashboard because buying an embedded analytics solution “seemed expensive” at $2,000/month. Fast forward 18 months. They’ve burned $120K in engineering time maintaining it, it still doesn’t have the features their enterprise customers expect, and now it’s blocking a major deal because it can’t handle the data volume.
Talent opportunity cost
Your best engineers should be working on problems and features that increase the value of your software product.
When you choose to build a non-differentiating feature, you’re asking your talent to solve already-solved problems. This has consequences beyond the immediate project.
Your lead backend engineer didn’t join your company to build another OAuth implementation or reverse-engineer how Stripe’s webhook system works. They joined to solve the unique challenges in your domain. If you make them spend six months on commodity infrastructure, you’re just increasing your attrition risk.
This is the talent opportunity cost, and it’s invisible on the balance sheet. But it shows up in:
- Longer time-to-hire when good engineers hear about your tech stack decisions
- Higher churn among senior ICs who feel their skills are stagnating
- Slower velocity on actual differentiating features
- Reduced innovation because your team is in maintenance mode
If you are applying a strict buy vs. build framework the dynamic changes. Your engineers get to stay focused on the problems only your company can solve and driving innovation. The features that make customers say “wow, nobody else does this.” That’s where breakthroughs happen.
A framework that provides clarity
Here’s a simple framework for product teams to cut through the noise:
Score each potential feature on two axes:
Strategic differentiation: Does this feature create competitive moat? (0-10)
Implementation complexity: How hard is this to build AND maintain? (0-10)
Plot them on a grid:
- High differentiation + High complexity = Build (this is your core IP)
- High differentiation + Low complexity = Build fast (quick wins)
- Low differentiation + Low complexity = Buy or ignore (don’t waste resources)
- Low differentiation + High complexity = Buy (this is where ISVs bleed resources)
That last quadrant is where most bad decisions happen. Teams see a complex feature, assume “nobody could build this as well as us,” and commit to 6 months of development hell.
Making the call
For most features, when you run through this framework honestly, the answer is buy. And that’s exactly the point. The best ISVs in 2026 are the ones with the discipline to say no to building everything.
Do fewer things in-house but do them exceptionally well. Be the best in the world at 3-5 core capabilities and buy or partner for everything else.
Your engineering capacity is finite. Your market window is closing faster than ever. And your customers don’t care whether you built it or bought it. They care whether it works brilliantly and solves their problem.
The buy vs build decision isn’t about pride or giving up control. It’s about focus.
Bonus food for thought: Have you ever considered if your software could provide value to other ISVs so they don’t have to build what you’ve already mastered? If you’ve solved a hard problem, you might just be the vendor someone else is looking for and open up a new revenue stream.
