Role
UX/UI Designer
Client
Yettel Bulgaria
Plataforms
Web & App
Overview
Yettel Bulgaria was undergoing a major digital transformation to modernize its sales and customer care platforms. The vision was to create a scalable design system that unified the brand’s digital presence while improving key customer journeys with a modern, accessible, and consistent user experience across mobile and web.
Many of Yettel’s core services — such as plan upgrades, account management, and service activations — were only partially digital, requiring physical store visits or calls to customer support. The goal of this initiative was to provide users with end-to-end digital self-service capabilities, while giving internal teams a sustainable, efficient design foundation to build on.
When I joined, the project had already been underway for a year. My contributions focused on three areas: refining the design system with haptic feedback guidelines, redesigning critical customer journeys, and creating interactive prototypes that simulated real-world behavior for stakeholder validation and user testing.
My Role
As a UX/UI Designer, I worked closely with designers, developers, researchers, and stakeholders, ensuring every decision balanced user needs, business goals, and technical constraints. My responsibilities included:
Reviewing every component in the design system to ensure consistency and usability.
Designing detailed flows and high-fidelity screens for both mobile and web.
Creating interactive Figma prototypes for realistic journey testing.
Writing documentation that outlined rules and best practices for haptic feedback.
Supporting cross-team alignment through collaborative workshops and review sessions.
The Challenge
The legacy platform was fragmented, with inconsistent visual patterns and outdated UI across multiple touchpoints. This created confusion for customers and inefficiencies for internal teams, who had to maintain multiple, disconnected design frameworks.
On top of this, many customer actions ( like transferring a number, upgrading a plan, or tracking consumption) could only be completed offline. This resulted in high dependency on physical stores and call centers, slowing down service and increasing operational costs.
The redesign aimed to solve these issues by:
Establishing a single, scalable design system for mobile and web.
Bringing more services into the digital ecosystem to reduce friction for customers.
Creating a future-ready foundation for continuous innovation and growth
Design System Documentation
In addition to components and visual updates, I helped produce comprehensive documentation for designers and developers.
This included specifications for component usage, accessibility standards, sizing, spacing rules, and the newly introduced haptic feedback patterns.
The documentation ensured that future updates could be implemented consistently and efficiently, reducing reliance on ad-hoc decision-making and maintaining design integrity over time.
Introducing Haptic Feedback
One of my key contributions was integrating haptic feedback into the mobile experience. Haptics are essential for making interactions feel tactile and natural, particularly in telecom apps where confirmations, warnings, and navigation cues benefit from subtle physical feedback.
I began by creating clear documentation explaining what haptics are, when to use them, and where to avoid overuse. Working with researchers, I analyzed every component in the design system and identified where haptic feedback could improve usability. My recommendations were then presented to the design and development teams, refined through collaboration, and approved for implementation.
The result was a standardized haptic feedback layer embedded directly into the design system, ensuring consistent and meaningful use of tactile feedback across the app.
Interactive Prototypes for Testing
To validate these redesigned journeys, I built advanced interactive prototypes in Figma. These were not static click-throughs, but dynamic simulations designed to mimic the behavior of a live app as closely as possible.
The prototypes included:
Multiple branching paths to reflect real user decisions.
Dynamic content updates, such as pricing and plan details changing in real time.
Animated transitions and state changes for a smooth, realistic feel.
Once created, the prototypes were reviewed internally by product managers, marketing, and developers to ensure alignment. After validation, they were handed off to an external research company, who conducted usability testing with real users.
The feedback from these sessions informed further refinements to the designs and flows before moving toward final delivery.
Redesigning Customer Journeys
Alongside work on the design system, I helped redesign several customer journeys, including plan upgrades, consumption management, and account services.
Each journey began with mapping out requirements and understanding every interaction point. Using a mobile-first approach, I designed streamlined flows that prioritized ease of use on smartphones before scaling up to desktop web.
These flows were then translated into high-fidelity designs that followed the new design system, ensuring a consistent and accessible experience across all screens. Complex journeys like number portability were carefully structured to reduce friction while meeting business needs.
Results and Impact
The updated platform provided Yettel with a modern, unified digital ecosystem. Customers gained more control over their services, completing tasks digitally that once required physical visits or long support calls.
For the company, the project delivered a future-ready design system, improving collaboration and speeding up development cycles. The introduction of haptic feedback elevated the mobile experience, making it feel responsive and premium, while the interactive prototypes helped validate ideas early and reduce development risk.
Conclusion
The Yettel Bulgaria transformation was more than a visual refresh. It was about creating a sustainable foundation for growth through a robust design system, modernized customer journeys, and thoughtful interaction design.
By integrating haptics, building advanced prototypes, and ensuring every detail was documented, we delivered a scalable ecosystem that benefits both customers and internal teams, setting the stage for ongoing innovation.