Custom Web App vs SaaS: How to Choose in 2026
Your company needs a digital tool. Should you subscribe to an existing SaaS product or invest in a custom application? This guide compares both approaches to help you make the right call.
The dilemma every growing company faces
As a company grows, its generic tools quickly hit their limits. Spreadsheets overflow, manual processes slow everything down, and off-the-shelf SaaS covers only 80% of what you need. That is when the question arrives: adapt your processes to an existing tool, or build a tool that fits your processes?
SaaS: speed and simplicity
Advantages
- Immediate deployment: you are up and running in days, not months.
- Low upfront cost: a monthly subscription of EUR 50 to 500 depending on complexity.
- Maintenance included: updates, security and hosting are the vendor's problem.
- An integration ecosystem: most SaaS products connect to your existing tools through APIs.
Drawbacks
- Limited customisation: you have to adapt your processes to the tool, not the other way round.
- Vendor dependency: if the SaaS shuts down or changes its pricing, you are stuck.
- Data hosted elsewhere: which raises GDPR compliance and sovereignty questions.
- Cumulative cost: over five years, a SaaS at EUR 300 a month comes to EUR 18,000 — without ever owning the tool.
A custom application: investment and ownership
Advantages
- 100% fitted to your needs: every feature is designed around your workflow.
- Competitive advantage: your tool is unique, and your competitors do not have it.
- Full ownership: the code, the data and the infrastructure are yours.
- Unlimited extensibility: add features whenever you want, without waiting on a vendor.
- Compliance under your control: GDPR, hosting in France, complete auditability.
Drawbacks
- Upfront investment: budget EUR 15,000 to 80,000 depending on complexity.
- Time to production: two to six months for a working MVP.
- Maintenance to plan for: hosting, security and ongoing development all need an annual budget.
The comparison in numbers
| Criterion | SaaS | Custom |
|---|---|---|
| Year one cost | EUR 600 - 6,000 | EUR 15,000 - 80,000 |
| Five-year cost | EUR 3,000 - 30,000 | EUR 25,000 - 100,000 |
| Time to deploy | 1-7 days | 2-6 months |
| Customisation | Limited | Unlimited |
| Ownership | Rented | Fully owned |
| Competitive advantage | None (the same tool as your competitors) | Significant |
When should you choose SaaS?
- Your need is standard (CRM, invoicing, email marketing)
- You are an early-stage startup with a limited budget
- You need to be operational tomorrow
- Your processes are simple and not a differentiator
When should you invest in custom?
- No SaaS product covers more than 70% of what you need
- Your business process is your competitive advantage
- You have compliance constraints (GDPR, health data, a regulated sector)
- You are expecting strong growth, at which point SaaS becomes too expensive
- You want control over your data and your infrastructure
Our approach at Beyond The Brackets
We do not automatically recommend building custom. Sometimes a well-configured SaaS is the better answer. Our job is to help you make the right choice, and then to execute it. We have guided more than 30 companies through this decision and built business applications for sectors as varied as real estate (Brandywine), art (InventoZen), telecoms (Color Telecom) and e-commerce (McWhirter).
Our technical stack — Next.js, NestJS, PostgreSQL, React Native — lets us ship MVPs in six to ten weeks, with code quality that keeps them maintainable long term.
Torn between SaaS and custom?
Take 30 minutes with our team to work through what you need. A free first conversation, no strings attached.
Book a free call