From user insight to shipped product.
Product design for B2B and consumer products across fintech, SaaS and e-commerce. Research, flows, UI, prototyping and design QA, measured by what users actually do.
Selected work
4 case studies
Streamlining UX at Celonis
Reduced onboarding friction, boosted workflow success rates, and established scalable research frameworks.
Redefining Digital Car Ownership Through User-Centered Design
Simplifying car maintenance with a mobile-first app, growing customer retention rates by 5–9% MoM.
Transforming Beauty Appointments: Designing an Intuitive Online Booking Flow for Freshly
An all-in-one platform for beauty salon business owner to manage their day-to-day operations.
Bridging Mobile & Desktop: Redesigning Whistle’s Selling Experience for Increased Conversions
Whistle is a selling app to resell electronics, like iPhones, MacBooks, iPads, and other electronic devices.
What people say
TestimonialsKostas has a really pleasant personality & a good sense of humour which helps break the ice and can be very effective in putting users at ease in usability tests. He learns fast and maintains a calm demeanor and thinks clearly in difficult or stressful situations which is a great advantage in a teammate.
HalaStaff Product Designer · Celonis We have worked with Kostas on numerous projects and he is always professional, timely and executes his product design process fluidly. Kostas is a great asset on any project we work with him on. We highly recommend him for your app design, web design needs.
AndrewHead of Product Design · Kaleo DesignWorking with Kostas has been a very positive experience. He's very communicative and able to quickly pick up any project. His unique mixture of UX and Online Marketing make him a valuable partner of BTNG.
PhilipCo-founder · BTNG StudioKostas is a fantastic person to work alongside. His efficiency and work ethic are great at delivering projects quickly and his knowledge helped me out no end.
BenTeam Manager · Former ColleagueKostas and I worked on making the first contact points with our product an easy and intuitive experience. He continuously championed our users, thereby facilitating a user-centred design. Thanks to his excellent work, we understand our users better, and the product is easier to use. Kostas is also a pleasant and fun person to work with.
SebastianProduct Manager · Celonis
About
Kostas PapageorgiouI'm a product designer and UX researcher, originally from Greece and now based in Northern Ireland.
I like work where research and evidence decide the design, and where I can follow an idea all the way into the shipped product.
- Now
- Product designer, EverQuote
- Before
- Celonis
- Craft
- UX/UI, user research, prototyping, documentation
- Tools
- Figma, HTML/CSS, Claude Code, Notion
Writing
All posts →Got questions?
FAQsWhat's your design process?
My process adapts to the project, whether refining a design system, shaping a new feature, or building a product from scratch.
I start with deep research to align user needs with business goals, then define key flows, prototype, and refine through iteration.
Collaboration with engineering is essential, ensuring smooth handoffs with clear documentation in Figma. Design QA is non-negotiable. I test for responsiveness, accessibility, and interaction quality. After launch, I track performance and user feedback to refine the experience. The goal is not just to ship a product, but to create something intuitive, scalable, and impactful.
How do you balance user needs with business goals?
I start with research to uncover user pain points, behaviors, and motivations, then map those insights to business objectives.
The key is finding alignment, where improving the user experience also drives measurable business impact. If the goal is higher conversions, I streamline the journey, reducing friction without compromising usability. I use prioritisation frameworks like value vs. complexity matrices to focus on high-impact, low-effort solutions.
A/B testing and user feedback guide decisions, ensuring every design choice enhances both user satisfaction and business outcomes.
How do you approach UX research?
Every project is different, so I adapt my research methods to uncover insights.
I blend qualitative insights with data-driven validation. I uncover user behaviors through interviews, usability testing, and contextual inquiries, then validate at scale with A/B testing, behavioral analytics, and AI-driven insights like sentiment analysis.
I use journey mapping, heuristic evaluations, and evolving personas to guide decisions. Rapid prototyping and concept testing ensure market fit before launch, while post-launch analytics track adoption and engagement. By integrating emerging tools and methodologies, I make sure every design decision is user-focused, business-driven, and future-proof.
What design tools do you use?
Figma is my go-to for UI/UX design, prototyping, and developer handoffs. Canva simplifies quick asset creation, while Rive enables interactive animations.
AI tools are transforming design, and I integrate Claude for content ideation, Midjourney for visual concepts, and for custom assets. I also leverage tools like Pendo, Hotjar and FullStory for real-time user insights, ensuring data-driven design decisions.
How do you communicate design concepts?
I combine interactive prototypes, storytelling, and data to align stakeholders and teams. Figma prototypes and Rive animations make concepts tangible, while AI tools like Runway ML and Midjourney enhance visual storytelling.
I keep presentations focused on the "why" by demonstrating how design choices address user needs and business goals.
For async collaboration, I use Loom, Slack, and Notion for clear, structured updates and documentation.
In reviews, I facilitate discussions using tools like Miro and FigJam, ensuring alignment while incorporating insights efficiently.
Are there any types of work you don't do?
I focus on UX and UI work. I don't do 3D modelling, print design, packaging, or GIFs.
Say hello
Open to conversations$ whoami kostas · product designer $ contact --book https://cal.com/kpgrio/20mins