The honest answer: it depends on what you're building. But "it depends" isn't useful when you're trying to budget, so here's what custom web application development actually costs based on real projects.
I've built 50+ web applications over 17 years — from €5,000 MVPs to €80,000+ enterprise platforms. This breakdown reflects real pricing, not theoretical ranges from agencies that haven't shipped software.
Quick Cost Overview
| Project Type | Cost Range | Timeline | Example |
|---|---|---|---|
| MVP / Proof of Concept | €8,000 – €15,000 | 4-6 weeks | Landing page + core feature + payments |
| Standard Business App | €15,000 – €40,000 | 8-14 weeks | Full app, multiple user roles, integrations |
| Complex Enterprise Platform | €40,000 – €80,000+ | 3-6 months | Multi-module system, complex logic, high availability |
These ranges assume a solo senior developer. Agency pricing typically runs 2-3x higher for the same deliverable.
What Drives the Cost
Complexity of Business Logic
A portfolio website with a contact form is fundamentally different from a facility management portal with contract workflows, role-based permissions, and audit trails. The difference isn't just "more pages" — it's the underlying logic that determines how data flows through the application.
Simple business logic (CRUD operations, basic forms, list views): lower cost.
Complex business logic (multi-step workflows, approval chains, calculated fields, conditional rules): significantly higher cost.
Real example: OpsPortal — a facility management system with 4 user roles, 22 data models, 45 permission rules, calendar scheduling with recurring rules, and performance tracking with photo evidence. This level of business logic complexity pushes a project into the €30,000-50,000 range.
Number of Integrations
Every third-party integration (payment gateway, CRM, ERP, email service, analytics, AI model) adds development time. Some integrations have clean APIs and take a day. Others have poorly documented APIs and take a week.
Common integrations and typical time:
- Stripe payments: 2-3 days
- Email service (SendGrid, Resend): 1 day
- AI/LLM integration (Claude, GPT): 3-5 days
- CRM sync (HubSpot, Salesforce): 3-7 days
- Custom API integration: 2-5 days per integration
User Roles and Permissions
A single-role application (all users see the same thing) is straightforward. A multi-role application (admin, manager, employee, client — each seeing different data and having different capabilities) multiplies complexity significantly.
Each additional role typically adds 10-15% to development time because every feature needs to be tested and secured for each role's perspective.
Design Requirements
Template-based design (using existing component libraries): minimal cost impact.
Custom UI/UX design (Figma prototyping, custom components, animations): adds €3,000-8,000+.
For most business applications, a clean interface using established design patterns (shadcn/ui, Tailwind) delivers better usability than over-designed custom interfaces. I always recommend investing in UX clarity over visual novelty.
Solo Developer vs. Agency: Cost Comparison
| Factor | Solo Senior Developer | Mid-Size Agency |
|---|---|---|
| Daily rate | €400-600 | €800-1,500 |
| Communication | Direct with engineer | Through PM layer |
| Consistency | One codebase style | Multiple developers, varying quality |
| Overhead | None | Office, sales, management (30-40% of cost) |
| Typical MVP cost | €8,000-15,000 | €20,000-40,000 |
| Typical enterprise project | €40,000-80,000 | €100,000-200,000+ |
The trade-off: agencies can throw more bodies at a project for faster parallel development. A solo developer provides consistency and direct accountability.
How to Budget for Custom Development
Start with the problem, not the feature list
Define what business problem the application solves and what success looks like. "We need a portal" is expensive to estimate. "We need to reduce client onboarding from 5 days to 1 day" is specific enough to architect and price accurately.
Consider MVP first
Unless you're certain about every feature, build the minimum viable product first. Launch with core functionality, get real user feedback, then iterate. I've seen too many projects burn €50,000+ building features that nobody ended up using.
Budget for post-launch
Applications need maintenance, updates, and iterations after launch. Budget 15-20% of initial development cost annually for maintenance. Bug fixes, security updates, and small feature additions are part of running a live application.
Ready to Get a Specific Estimate?
Send me a brief description of what you need. I'll respond within 24 hours with an honest assessment — including whether custom development is the right approach for your specific case.
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