UX/UI Designer - Senior

Freelancer Opportunity

Job title: Senior UX/UI designer

Job location: Brussels - Hybrid (2days/week at the office)

Job contract type: Freelance, 6-month mission with possibility to extend

Role description:

At Proximus, we are looking for a Senior UX/UI Designer to play a key role in shaping the future of the Proximus+ app as a trusted omnichannel hub for our customers.

You will work within the Ecosystem Design Chapter and take ownership of key app experiences. Your mission is to help Proximus+ deliver simpler, more personalized, and more proactive experiences in line with customer needs. This role is ideal for a senior app designer who thrives in autonomy, is comfortable navigating ambiguity, and wants to actively influence how AI, personalization and conversation shape the future of the Proximus+ app.

Key responsibilities:

As a Senior UX/UI Designer, you will:

Drive the overall UX/UI and experience of the Proximus+ mobile app.

Translate strategic objectives and value propositions into clear concepts, user journeys and flows.

Design wireframes, high-fidelity interfaces and interactive prototypes for mobile, balancing user needs, business goals and technical constraints.

Design and optimize conversational flows (chat, guided journeys, proactive messaging), ensuring clarity, relevance and trust.

Design experiences optimized across touchpoints, aligning in-app experiences with web, physical stores, customer support, and assisted channels.

Lead and conduct user research and usability testing, selecting appropriate methods to validate concepts and design solutions.

Turn research, analytics, and customer feedback into clear design decisions and measurable improvements.

Actively contribute to and evolve the design system and UX standards, ensuring consistency and quality across the app.

Collaborate closely with product owners, analysts, developers, and other designers, while confidently challenging assumptions and proposing alternatives when needed.

Present and defend design decisions to stakeholders and leadership.

Proactively identify experience gaps and opportunities, particularly around onboarding, personalization, conversational flows, and AI-driven features.

Collaborate with business and technical stakeholders to define where and how AI and conversation meaningfully improve the customer journey.

Take full accountability for UX quality within your scope, following up on implementation and outcomes.

Experience & Background:

Bachelor's degree in computer science, Information Systems, Graphic Design, Product development, Psychology or related field, or equivalent work experience.

5+ years of experience as a UX/UI designer, with proven end-to-end ownership of design work.

Significant experience designing mobile apps in complex, large-scale environments.

Strong background in user research, from exploratory research to usability testing.

Experience designing for AI-powered products or assistants.

Skills & expertise:

Excellent command of Figma for UX/UI design and prototyping.

Strong understanding of mobile UX patterns, interaction design, and accessibility.

Knowledge of Content Square, Adobe Analytics or other analytics tools to inform and validate design decisions.

Solid understanding of Double Diamond and human-centered design principles.

Mindset & ways of working:

We are specifically looking for someone who:

Brings an analytical and data-driven mindset.

Is deeply customer-focused, with a hands-on, pragmatic, and can-do mentality.

Is a strong facilitator, able to lead workshops, align diverse stakeholders, and guide teams toward shared decisions.

Has strong stakeholder management and influencing skills, able to navigate differing opinions and push back constructively.

Thrives in complex and evolving contexts, able to stay effective in the face of ambiguity, change and bring clarity.

Works confidently autonomously, taking initiative and ownership while keeping stakeholders aligned.

Communicates clearly and confidently, adapting their message to different audiences.

Demonstrates strong planning and organizational skills, coordinating projects across multiple tribes and departments.

Is curious, future-oriented, and motivated by shaping what comes next, especially in the context of AI and evolving digital experiences.

Languages:

Fluent in Dutch or French, with strong English (spoken and written).

Nice to haves:

Experience with service design and cross-channel journeys.

Experience in telecommunications or similarly complex industries and corporate environments.

Familiarity with Agile product development environments.

Apply now and start your journey with Team Possible! We want to get to know you.

After your application, we will verify your profile and get back to you within 3

working days.

If you’re successful, you can expect the following steps:

An initial conversation with our recruiter - Swati Kumari

Interview with the Hiring Manager and the team.

Final decision

About Proximus

We are Team Possible turning tech into opportunities.

We are driven by four core pillars: "I care," "I make a difference," "I radically simplify," and "I embrace the future". This means you'll join a team that genuinely cares for customers and colleagues, is empowered to make a real impact, strives to radically simplify complex challenges, and is always looking ahead to embrace the future of technology. We believe in an inclusive and safe environment where everyone can thrive, offering extensive career development resources, including access to over 5,000 training modules and a minimum of 5 days of training per year, to help you continuously learn, grow, and tackle bold challenges with us.