Build vs buy for technology platforms: a decision framework

The build-versus-buy decision is about where engineering capacity creates the most value. Building gives control and differentiation at the cost of ongoing ownership; buying gives speed and maturity at the cost of dependency. A simple framework makes the trade-off explicit instead of leaving it to habit or preference.

Question 1: does it differentiate?

Ask whether customers would choose your product because of this capability.

• Core differentiators — the parts of the product customers pay for. In a travel platform, that might be pricing logic, the order model, supplier mix or the booking experience. Strong case to build.
• Context — necessary but not distinctive: email delivery, payment processing, authentication, monitoring, accounting. Strong case to buy.

Engineering time spent on context is time not spent on differentiation.

Question 2: what is the full lifetime cost?

Compare total cost over several years, not the first quarter:

Cost	Build	Buy
Initial	Design and development	Licence, setup, integration
Ongoing	Maintenance, security, upgrades, operations, on-call	Subscription, usage fees, price increases
People	Engineers who understand it	Admins and integration owners
Opportunity	Features not built elsewhere	Workarounds for missing features
Exit	Little — you own it	Data migration and re-integration

Maintenance is the line most often underestimated for building; integration and price growth are most often underestimated for buying.

Question 3: how much control do you need?

Some capabilities need control over behaviour, data or roadmap:

• regulatory or contractual obligations on data location and handling,
• performance or availability requirements beyond what vendors offer,
• deep integration with internal models, such as a booking engine’s order service,
• a roadmap you cannot wait for.

If a vendor cannot meet these, buying only postpones the build.

Question 4: how hard is integration?

Bought software still has to fit your platform. Assess:

• the quality of its APIs and webhooks — see API design for B2B partners for what good looks like,
• whether its data model matches yours or forces translation everywhere,
• authentication, permissions and audit integration,
• data export options.

Poor integration can make a bought product cost more than a built one.

Question 5: what is the exit plan?

Every bought dependency should have an exit path: data export in usable formats, an internal abstraction around the vendor so it can be replaced, and contract terms that avoid lock-in. Wrapping vendors in adapters — the same idea as supplier adapters in travel — keeps switching costs manageable.

The third option: integrate and extend

Many decisions are not binary. Common middle paths:

• buy the commodity core and build the differentiating layer on top,
• use open-source components and own the operations,
• start with a vendor to learn the domain, and build later once requirements are proven.

In travel, platforms often buy supplier aggregation for long-tail content while building direct connections and pricing for the markets that matter most.

Revisit decisions

Build-versus-buy is not permanent. A vendor that fit at ten customers may not fit at a thousand; an internal tool may become a commodity the market now serves well. Review major decisions periodically against the same questions.

The takeaway

Build what makes you different and what you must control. Buy what is commodity and well served. Compare lifetime cost honestly, insist on good integration and a clear exit, and accept that the right answer changes as the company grows. Related discussion of early-stage scope is in shipping a B2B platform MVP.