Customer portal development: self-service that takes the load off your support team and becomes a sales channel

A portal MVP with Keycloak login and first self-service features runs €8,000–20,000. A complete customer portal with roles, company accounts, and a first ERP integration costs €20,000–60,000; a multi-tenant portal platform with multiple integrations, €60,000–150,000. All ranges are net of VAT and come from real projects. Which class your project falls into — and whether custom development pays off at all — is what we settle in an upfront discovery.

It depends on the ERP depth you need. If standard support without deep integration is enough, buy SaaS like Zendesk and skip the development cost — we'll say so even when it costs us revenue. Custom development pays off when customers need to pull orders, invoices, and documents straight from your systems and SaaS costs would grow by a factor of 3–5 as you scale. Often a hybrid is the pragmatic path.

A portal MVP with login and first self-service features goes live with us in 6–12 weeks. That lets you validate the business case against real user behavior before making the larger investment in a role model and ERP integration. Complete portals with integrations take correspondingly longer; we set the concrete timeline in the discovery that precedes every project.

Through interfaces that pull orders, invoices, and master data from your ERP or CRM into the portal — via API, middleware, or synchronization, depending on the system. The portal can also sit as a modern layer in front of a legacy ERP: your customers work with a contemporary interface while the core system stays untouched. Which systems you run and how deep the integration needs to go is what we assess in the discovery.

Both are open source and run on EU infrastructure you control — with no license fees that scale with user counts and no data transfers to third countries. Keycloak handles SSO, roles, and company accounts; Supabase provides the database and tenant isolation via Row Level Security. The demand for European providers is measurable: according to Bitkom 2025, 82% of German companies want hyperscalers from Germany or Europe.

A website informs and generates leads — no login. A web app maps processes, usually for your own employees. A customer portal is technically a web app, but the users are your external customers: they sign in and handle requests themselves that would otherwise go through email and phone. What matters is the use case, not the technology — and that's also what drives the ROI logic.

The open-source stack's infrastructure costs €20–50 per month, or €150–400 for high availability. Add 2–5 hours of operations per month at approx. €120/h for monitoring, updates, and Supabase/Keycloak maintenance. Over three years, the stack's TCO comes to €40,000–80,000 — disclosed in full on our blog. Ongoing development via retainer costs €4,000–12,000 per month, as a predictable alternative to your own senior hire.