The interface is only one part of the service.
A portal can be easy to look at and still be difficult to use. The missing piece is often outside the screen: an unclear requirement, a manual handover or a decision the user cannot see.
Before drawing an interface, map the whole journey. What brings someone here? What do they need to prepare? Who acts on their request? What happens when something goes wrong?
Make the next step understandable.
A useful service tells people what they can do, what information they need and what will happen afterwards. Write those explanations before treating the interface as finished.
Test the journey with ordinary tasks and realistic constraints. Include someone using a keyboard, someone on a small screen and someone encountering the service for the first time.
Design the handovers too.
A submission usually becomes work for another person or system. Define ownership, status transitions and how an incomplete request gets resolved. An elegant front end cannot compensate for an undefined process behind it.
Start with one complete service journey. Learn from it, then expand the platform without losing the clarity that made the first journey work.