Charles de Mount Yahouédéou
Hello! I'm Charles, a Design Engineer with 5+ years of experience building polished product, marketing, and developer-facing interfaces for high-growth startups. As a "community-taught" developer, I started my professional career in a microbiology lab, but that scientific curiosity is exactly what drives me to understand how people interact with software. I'm currently a Design Engineer at Clerk.
I'm driven by the desire to build intuitive and delightful user interfaces. This passion has led me through high-growth startups like Clerk, Vercel, and SuperHi, where I've focused on turning complex problems into interactive and accessible solutions while earning multiple design awards.
Career
Clerk–
⤷ Design Engineer
In early 2026, I joined Clerk, the authentication and user management platform for developers, as a Design Engineer. After years of building for developer-facing products, I was thrilled to shape how developers first meet Clerk, from the marketing site to the product surfaces they use every day.
I shipped new designs for 2 product landing pages and scaled them into a composable architecture now reused across 4 more pages, improving performance, accessibility, and developer experience along the way.
Beyond the pages themselves, I designed and built interactive component demos that mirror real Clerk flows, making our product education and component storytelling far more tangible.
Projects
Freelance–
⤷ Design Engineer
After my time at SuperHi, I spent a year as an independent Design Engineer, partnering with early-stage startups and agencies to ship polished, production-ready interfaces. It was a chance to work across very different products while staying close to both the design and the code.
I redesigned Pydantic Logfire's navigation and information architecture, shipping a new sidebar and motion conventions that made it far easier to find your way around complex observability setups. Alongside that, I delivered motion-first landing pages for agency clients launching around key funding milestones.
SuperHi–
⤷ Frontend Developer 
Senior Software Developer, Frontend & Design Systems
I spent almost 3 years of my career (May 2022 - Dec 2024) at SuperHi, a one–of–a–kind education startup with an incredible team and culture. Having written my first few lines of code alongside SuperHi courses, I was excited to participate in the next phase of the company growth.
Initially hired as a Frontend Engineer, I set out to build, document, and iterate on a flexible design system to handle the growing number of projects we were building while keeping our design language consistent. I also helped improve workflows with better testing, logging, and documentation, which even sped up how quickly we could launch new courses. Through those efforts, we reduced the time taken to build new courses from months to just 2 weeks. We launched 12+ new courses, growing our user base massively and helping as many instructors get paid for their work.
Thanks to those contributions, I was quickly promoted to Senior Software Engineer, where I continued to architect solutions and work across the stack, boosting revenue by 22% with proactive changes and improving user retention by 10% by tackling UX issues such a building a new video player. In addition, I optimized our performance metrics, improved our security, built a brand new dashboard, and even prototyped new avenues like AI-powered learning tools.
Projects
SuperHi Platform Redesign
Spearheaded a platform redesign at SuperHi that drove a 22% increase in conversion and a 209% customer growth for over 50,000 users. I led the technical execution, which involved a full-stack migration to Next.js 14, implementing a new, award-winning front-end, and redesigning core content, the dashboard, and the video player experience.
SuperHi Website SuperHi Plus
SuperHi Plus is a program by SuperHi, making it easier to recruit promising creatives from around the world and mentor them to become educators. I drove a 47% increase in traffic to SuperHi's main site through the successful launch of the SuperHi Plus sub-brand. As a Frontend Engineer, I developed the program's engaging and interactive website, focusing on motion and performance to create an immersive user experience. The launch exceeded all targets, attracting over 14,000 visitors and doubling the expected number of applicants.
SuperHi Plus Website Bounties
Bounties was a SuperHi platform designed to make it easier for freelancers to find creative projects and get paid transparently. Based on Ethereum smart contracts, clients would put their project funds in escrow which would then be used to pay creators after their work was completed. It was my first forray into building for Web3, and understanding the challenges of creating a user-friendly experience for an audience unfamiliar with the technology.
Bounties Website
Vercel–
⤷ Customer Success Engineer
In late-2021, I was elated to join Vercel as a Customer Success Engineer, a hybrid role which allowed me to work both on the customer side and the product side for our excellent support engineering team. I was responsible for providing direct technical support to customers of all tiers, being on-call for platform incidents, giving technical guidance to our enterprise customers, and adding new features to our internal tooling.
Working at Vercel was a wonderful learning experience, as I was able to work alongside some of the best engineers in the world, in a culture dedicated to shipping fast! I developed a deep understanding of serverless architecture, Next.js, and the building and deployment pipeline necessary to ship at scale.
Projects
Vercel Admin
I maintained and improved the Vercel Admin, an internal tool helping the CSE team, and others, manage customer requests by querying, updating, and deleting projects, deployments, domains, and more. I was responsible for iterating on the tool's core features and infrastructure, improving our internal velocity by 50% on recurring tickets by reducing resolution time.
Vercel Support Page
I built a new support page for Vercel, facilitating the migration of hobby tier customer support to GitHub Discussions. This allowed us to focus on our paid customers, reducing incoming support requests by over 30% and reducing the workload on our CSE team.
Lyncxs–
⤷ Co-Founder & Lead Product Engineer
A couple months after writing my first few lines of code, I joined hands with a B2B sales veteran to build Lyncxs (formerly: C360HD): A panoramic virutal tour booking platform for retail businesses.
I was responsible for the company's branding and design, as well as building the platform's core features and infrastructure. We launched to over 100 businesses in Montreal, automating operations for 40+ agents and generating $50K in revenue within our first 12 weeks.
Projects
Lyncxs Marketing Site
I designed and built the Lyncxs marketing site with Next.js, TypeScript, and the Google Maps API. It included multiple features such as a multi-step booking flow, a custom booking calendar. This site was the main touch point between our sales team and potential customers. It improved our conversion rate by over 70% when first introduced compared to our initial MVP.
Lyncxs Website Lyncxs Internal Dashboard and Admin
I created an internal dashboard and admin for Lyncxs, which helped the team automate serveral steps of the service, including booking creation, payment processing, scheduling the calendar of our photographers, automating the virtual tour upload to Google Street View, and more.
Lyncxs Branding
I designed the Lyncxs branding, including the logo, website, and marketing materials used across social media.
Freelance–
⤷ Creative Technologist
I started my web development career as a freelance creative technologist, helping clients build their brands and websites. I worked on creating interactive and accessible websites for clients across the globe, working by myself or with international digital agencies such as SameSameStudio. My work was featured in multiple design awards, including Typewolf, and SiteInspire.
Projects
Various Websites
I built various websites for clients across the globe, working by myself or with international digital agencies.
Some of my freelance work
Extra
Enigma: A recreation of the Enigma machine
After watching the Imitation Game, I was inspired to build a recreation of the Enigma machine to understand its inner workings and test my knowledge of React.Enigma is a react-based version of the machine using useReducer to manage the state of the machine. The machine reliably encrypts and decrypts messages with the same settings as the original machine, including the various rotors, reflector, and plugboard.
Hearsay
I would highly recommend Charles to any team looking for a software engineer who goes beyond writing code — someone who truly understands how technology can create delightful, accessible and memorable experiences(…)
—Panna Nyeste, Head of Design at SuperHiCharles is one of those rare colleagues who provides insightful feedback, champions customer pain points that need product improvement, and is a delight to work with. During my time working with him, he stood out as an empathetic communicator and excellent developer(…)
—Juliet Jonak, Customer Success Manager at VercelCharles improved our whole engineering team with his initiatives. He implemented automated checks, high-quality testing, and better development practices. His technical skills, architectural thinking, and team commitment made him a talented developer. He is also one of the rare engineers who thinks about the return on investment and business needs for what they are working on, too(…)
—Rik Lomas, CEO at SuperHi