GUI redesign of the VoIP client from Pascom

  • Disciplines

  • Interaction Design
  • Visual Design
  • User Experience 

  • User Interface
  • Client

  • Pascom GmbH & Co. KG
By order of
  • seitenwind GmbH

Pascom is a fully open IP telephone system. The client can be set up on all common operating systems. Windows, MacOS, Linux, Android and iOS.

The task

For the 2019 update release, Pascom wanted new functions to be integrated into its client. The new main functions included channels, audio- and video conferences as well as screen sharing with moderator function.

Reviews and user journeys

After analyzing the reviews and a lot of research, I started sketching user journeys. The purpose of these journeys was to gain a better understanding of what users expect from Pascom. It became clear that some of the current problems are not only noticeable visually, but also interactively. The update offers the perfect opportunity to solve some of these problems.

Modular design system

Here, as so often, we use the aesthetic usability effect. This is the equivalent of "Whoa, what a handsome guy, he must have an amazing personality. If we don't understand each other, it's my fault. I'm terrible."

I started creating a component system whos parts are based on a 8dp baseline grid. Symbols, typography and some elements within the components can be aligned on a 4dp grid.


I replaced the old icon set with Google's material icons because of the simplicity, modernity and friendliness. Each icon is created in accordance to Google's design guidelines. Ongoing updates ensure that the icon set is always up to date.

The importance of alignment is often overlooked because it's invisible. Alignment helps us create a sense of unity in which structure and connecting elements are subtly provided.

The left sidebar

Users can use the left sidebar to switch between channels, chats and favorites. You can also create, sort, mute or favorize channels there.


This is where users spend most of their time. Unfortonatly, the messenger interface has the most design inconsistencies. The most striking are: alignment, spacing, font sizes and other interactive elements.

Video call interface

Nowadays it's all about collaboration. With the most advanced video conferencing solutions, teams can have conversations, send files, share the screen, and share ideas. Of course, Pascom has to catch up.

Put everything together

After developing a uniform and working design language, I had to make sure that every single piece worked for itself. The client could then be reassembled and published for alpha and usability tests.


Every software needs good design, because good design respects you, the user.