INTRODUCTION
‘Should we build our own system or subscribe to a platform?’ sounds binary, but the best answer is often a mix. Email, accounting, identity, payments and collaboration solve mostly standard problems. Rebuilding them adds maintenance without differentiation.
Other processes accumulate duplicate steps, parallel spreadsheets, manual exports, exceptions and fragile integrations because a generic tool does not fit. That is where another strategy deserves evaluation.
1. SaaS works well when the problem is standard enough
An existing platform can provide fast implementation, updates, support, mature capabilities and initially predictable cost.
- limits
- users
- data export
- APIs
- permissions
- price changes
- vendor dependency
- customization
Buy, build or combine
2. Custom software fits when adapting the business creates sustained friction
Proprietary rules, states, integrations, roles and logic that represent an advantage may justify custom development. Owning the code also means accepting maintenance, security, infrastructure, support and evolution.
Example: buy the commodity, design the differentiator
A company uses standard tools for invoicing and email. Field operations coordinate work orders, locations, evidence, inventory and owners through sheets and chats because no platform fits. It develops only the operating layer that differentiates the business.
3. The hybrid option can be powerful
Identity, payments, CRM, communications and storage can remain SaaS while a custom application coordinates the operating flow. API, webhook and data-contract quality determines whether that architecture stays maintainable.
4. Compare total cost, not monthly fee against development
| Factor | SaaS | Custom |
|---|---|---|
| Start | Faster | Requires discovery and development |
| Fit | Depends on configuration | Can reflect a proprietary process |
| Maintenance | Vendor plus internal administration | Product responsibility |
| Integrations | Depends on APIs | Can be designed but must be maintained |
| Data | Subject to platform and contract | Architecture set by the project |
| Differentiation | Limited | Potentially high |
This table is not an automatic rule.
5. Signs you may be forcing SaaS too far
- multiple parallel spreadsheets
- daily exports and imports
- the same data captured several times
- many manual exceptions
- users avoiding the system
- important work outside the platform
- growth blocked by limits
One sign does not justify custom software. Several persistent signs justify an evaluation.
From context to a decision.
Decide whether to buy, build or combine
Evaluate my operation↗Answers with the full context.
Is SaaS always cheaper?+
Not necessarily over the full lifecycle. Users, pricing, configuration, integrations, operations and time horizon all affect cost.
Does custom software mean starting everything from scratch?+
No. It can use existing services, APIs and platforms and focus on the differentiating logic.
Can I combine both?+
Yes. Standard systems can handle commodity functions while a custom layer coordinates the specific process.
When should I not build?+
When the process is standard, an existing solution fits well and owning a product would not create a clear advantage.
SOURCES AND REFERENCES1
References consulted for this editorial review.
- Choose the right tools and technologyGOV.UK Service Manual
