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Melissanthi Papacharalampous · Senior Product Designer portfolio

Mindstone Rebel Senior Product Designer

Designing open-source contribution agents for an AI-native desktop

I turned my design judgement into rules, agents, and a code-first system that helped Rebel stay creative while opening contribution beyond the core team.

Open sourceAI operating systemDesktop app

What collaborators say

From LinkedIn Recommendations

Working with Melissanthi was definitely one of the highlights of my time at Mindstone. She brought thoughtfulness, curiosity, and a deep commitment to growth, and over the course of my time at Mindstone, I was honored to support her evolution into someone who now confidently owns the design of the entire platform.

Working in an early-stage startup comes with no shortage of challenges, but every one she faced, she met with openness and grit. She actively sought feedback, reflected, and came back with learnings each time. What started as learning quickly turned into leading, and by the end, she was fully owning the UX within the team responsible for engagement on the Mindstone platform, bringing clarity, structure, and care to everything from flows to feature design.

She brings a strong product mindset: always digging into the “why,” asking sharp questions, and thinking about how design connects to real user outcomes. She collaborates beautifully across teams: open, grounded, and always generous with her thinking. It's clear how much stronger a team becomes with her on it. She learns fast, works with heart, and never lets ego get in the way of doing what's right for the user or her teammates.

She's an all-around awesome human. I'd hire her again in a heartbeat, and I truly believe any team would be lucky to have her. This is just the beginning of her journey, and I can't wait to see what she does next!

Melinda Jacobs
Co-CEO, Mindstone

In my time at Mindstone, Melissanthi was my first and most frequent collaborator. As a Product Designer, she played a pivotal role in shaping the product experience, and working with her was a true delight.

From fixing onboarding to designing the community experience and shaping AI features, she has a rare ability to simplify complexity while keeping users at the center. Her superpower? She's relentlessly customer-obsessed, diving deep to advocate for what users truly need.

Whether facilitating brainstorming and scoping sessions, leading user interviews, designing intuitive experiences, or collaborating with marketing to refine messaging, her work was instrumental in Mindstone's evolution from a general learning platform to an AI upskilling product users love.

Her ability to combine vision, empathy, and execution makes working with her an incredibly rewarding experience. Any team lucky enough to have Melissanthi won't just gain a talented designer, they'll gain a true product leader.

Kofo Adebiyi
Product Marketing Manager, Mindstone

I really should keep this a secret… I have worked closely with a lot of designers over the years, but I don't recall working with anyone as talented as Melissanthi!

I've had the pleasure of working with Melissanthi for the past six months at Everledger, and I could easily write a novel, but here are my top reasons for why Melissanthi is an exceptional designer:

  • She is highly organised, manages her time with such efficiency, and is always proactively seeking for ways to improve.
  • She has great communication skills; as a Product Manager I always know exactly what she is up to, and she is very professional when presenting or facilitating in front of clients.
  • She asks a ton of questions, to architects, developers, customers, clients, and myself, and she makes sure we constantly challenge the status quo and our decisions.
  • She is attentive, picks up on all the small things, and actively makes sure to follow up and move things along.
  • She is meticulous in her approach; nothing is left to randomness, and she bases her designs on solid (documented!) research and industry best-practices.

Melissanthi is a Swiss Army knife due to her unique ability to go above and beyond and solve every possibly challenge that gets thrown her way; design principles, user research, prototyping and wire framing, workflows or usability testing… If something is new to her, she will up-skill herself in a heartbeat!

If there was ever any doubt; Melissanthi is exceptional, and I am confident she will make it very far in life!

Sidsel Rytter Løschenkohl
Product Owner, Everledger

Melissanthi joined our agile product team at Office & Dragons last year, helping us design the next stage in our Transaction Development platform, focusing on the user experience and UI designs. Melissanthi demonstrated great technical UI/UX skills in her role and an ability to take feedback and iterate designs based on data and user research. She impressed me by not only taking ownership of the design work and producing high-quality results, but by taking initiative and displaying enthusiasm to get involved in more than just the tasks assigned to her. She is a great team player, excellent communicator and always looking to learn and expand her knowledge. It's bean a real pleasure working with Melissanthi, and I recommend her highly to any product or design team.

Samuel Smolkin
CEO & Founder, Office & Dragons