Interface design is the moment your product finally meets the user: everything decided in strategy and research sessions is proved or rejected inside a 360-pixel screen. At PBDP, web and mobile UI design starts from a signed-off wireframe and ends in a buildable handoff pack — not in a pretty picture for a board meeting. The deliverable is a coherent set of screens and states that stays readable on the smallest handset, understands right-to-left Arabic-script typography, and leaves engineering with no open questions.

Where UI ends and UX begins

Experience design decides what path the product offers; interface design decides how that path looks and feels: visual hierarchy, size and spacing, colour, type, button states and the feedback for every action. The boundary matters in practice, because a screen whose structure never came out of wireframing and prototyping cannot be rescued by beautiful styling — and flawless styling on the wrong structure only raises the redesign bill. Our job is to make both layers fit: logical decisions from research, visual decisions from design, and both documented.

How web interfaces differ from mobile app screens

Web works with a mouse, a keyboard and unpredictable viewport widths. Mobile works with a thumb, an on-screen keyboard and a user who is being distracted. Status bar height, the 44-pixel tap target, Persian keyboard behaviour, nested scrolling and gestures belong in the design file from the start, not in the revision round. For native work delivered through iOS app development, or mixed builds such as a cross-platform app, the platform guidelines are the starting point rather than the ceiling.

What you receive

• The full screen set: light and dark themes, plus empty, error, loading and success states for every screen.
• The visual system: colour palette, type scale in both scripts, spacing, elevation and radii, expressed as a design system.
• A component library: buttons, forms, cards, tables, modals and navigation in every possible state, reusable across releases.
• Responsive design: mobile, tablet and desktop layouts with defined breakpoints and content priority rules.
• Custom iconography and illustration: matched to the brand and to the metric conventions of the target platform.
• Developer handoff: source files, exported assets, measured values and interaction notes, ready for front-end development.
• A live preview: a staging link where screens can be opened on real devices and shown to users.

The process, step by step

1. Take the structure: review wireframes, personas and conversion paths, and confirm they are frozen.
2. Set the visual direction: two distinct routes presented on real screens, one chosen and the other rejected with a reason.
3. Design the key screens: the pages that carry traffic and revenue first, the rest following the same system.
4. Build components: recurring elements become a library so future screens cost less each time.
5. Review and test: a quality pass on real sizes, contrast and Persian readability, alongside usability testing.
6. Hand over and stay close: a walk-through with engineering and support through the first release.

Right-to-left, Persian and accessibility: three hard constraints

Most UI kits and templates are built left-to-right, and localising them afterwards produces a mirror image with the same problems: reversed arrows, broken date fields, scrambled tables and Latin numerals stranded inside Persian sentences. We set the RTL grid, Persian punctuation spacing, zero-width joins and number handling in the very first artboard. Accessibility is the second constraint: contrast ratios, minimum type size, labelled form fields and a logical keyboard focus order. Neither is a charity case — a legible, well-contrasted interface also performs better on mobile metrics and holds its ground in search results longer than a fragile one.

Frequently asked questions

Is UI design delivered without code?

Yes. This service produces design files, a live preview and a technical handoff pack. If you want implementation too, the same project team handles it — the advantage is that nothing is lost in translation, because design and code draw from one component system.

How is UI design priced?

By unique screens, number of platforms, states per screen and how custom the iconography and illustration need to be. We quote per screen rather than per hour, so before contracting you know exactly what arrives and at what depth.

We already have an in-house designer — what do we get from you?

Speed and standardisation: new screens inside your existing system, a design QA pass on what has been built, and the work your team never has time for — usually the mobile variants and the neglected states of long forms. Examples of that collaboration are visible in our project archive.

To see the screens and get a time and cost estimate for your own product, contact PBDP.