UX for complex systems
Booking platforms and transactional products made to feel simple. I work close to the dev backend and translate what it can do into flows people actually want to use — and convert on.
Hi, I’m Felix 👋
Senior product designer for 15 years across AKQA, Huge and Citi. I design and build revenue-critical flows end to end.
Taking on 1–2 engagements per quarter — contract or fractional, US & UK. GMT, full morning overlap with EST.
felixhornoiu@gmail.comVision Direct is one of Europe’s biggest contact-lens retailers, part of EssilorLuxottica. I reworked the high-frequency checkout and account flows, then scaled the UK system across seven markets.
The brief was a tightrope: cut friction on a recurring medical purchase and lift conversion without breaking a platform that makes real revenue every hour — so every change shipped incrementally, inside the existing system.
Payments, subscriptions, address management, autosave, prescription entry, a rebuilt cross-brand colour system, localised for the UK, Italy, Spain, France, Ireland and the Netherlands.
Keeps lets people buy, trade and cash out stakes in sport the way you would shares — alongside a secondary market where match tickets trade as options instead of fixed seats.
My role was a hybrid: UX across the whole platform working alongside the branding team, then taking their designs into a scalable, tokenised design system for part two.
Perfect Play translates academy-level training from Chelsea’s elite coaches and sports psychologists into a personalised app — 75+ activities, each with 3–6 levels, adapting to the player’s age and skill.
I worked as Product Designer across UX, systems design and prototyping — leading activity templating, onboarding, AR interactions and the performance mechanics behind adaptive training plans.
Ordo Pay lets small business owners — boiler engineers, cleaners, gardeners — send payment requests over the UK Open Banking API, while household users pay, part-pay or ask for an extension from one unified feed.
I led research and product design across the dual-sided experience — end-to-end flows from registration to requests, part-payments and dashboards, validated through Flinto prototypes and user testing.
Citi spun up a team to layer stocks, crypto, portfolios and advice onto its existing banking app. I was one of three product designers — flows, UI, interactive prototypes, testing, the lot.
The tricky part: it had to feel native to Citi’s existing app and taxonomy while serving three very different personas across a basic and an advanced mode, every section customisable.
Agile, fully remote, eight of us. We moved off Sketch onto Figma, prototyped in ProtoPie, user-tested every two weeks. Some screens stay blurred — NDA.

Instead of one feed for everyone, the app breaks the universe into bite-size cards and packs that reshape themselves per audience — devoted fans get depth, first-timers and under-13s get the on-ramp.
I ran research across those audience groups, built the component system that had to hold all of it, prototyped the “magical” micro-interactions, and tested seven rounds deep before handing anything to build.
No separate product, no new app — the fitting service rides the existing basket flow: add fitting, get an instant quote, pick an approved workshop nearby, book the slot. You still only pay online for the parts.
Three months with Big Light: research and competitor teardown, flow mapping with the tech team, wireframing the happy path and the annoying edge cases (postcode gates, VRM lookups, compulsory-vs-optional parts), then Principle prototypes tested on real car owners before visual design.
Booking platforms and transactional products made to feel simple. I work close to the dev backend and translate what it can do into flows people actually want to use — and convert on.
Tokenised, scalable design systems in Figma — components and variables structured to flex across brands, markets and platforms without breaking, with docs the whole org can adopt.
Advanced interactions — drag-and-drop, multi-touch gestures and micro-motion. Lottie out of After Effects via Bodymovin, and high-fidelity prototypes in Framer, ProtoPie and Principle. Also dabble in 3D design in 3D space, building scenes and object interactions for product surfaces.
Quantitative and qualitative testing that backs decisions with evidence — guerrilla sessions, interviews and remote testing — so the right calls get made for the right reasons, not the loudest.
I don't hand off and walk away — I code my own designs and work hand in hand with developers to get things shipped. A/B testing to validate what wins, front-of-the-front-end (HTML/CSS/JS) to build it, and living component libraries in Storybook so design and code stay one source of truth.
The job is to work, not to be admired at a portfolio review. If it doesn’t help, it’s cut.
The screen says what the system actually does, full stop. No dark patterns, no fake countdown timers.
Fewer flows, fewer states, fewer things to decide. Restraint is the actual skill here, not the add-ons.
Spacing, motion, copy, focus order. Nobody notices these when they’re right — everyone notices when they’re wrong.
Systems over one-off screens, so the work still holds up two rebrands later.
Good design doesn’t ask for applause. It gets out of the way and lets people finish what they came to do.
Faster iterations, same standards.
Working notes. Experiments, prototypes and dead ends from live projects — including how I use AI in the build.
Warner Bros., Google, Facebook, H&M, The Economist, EY, Microsoft, Coop, RAC and Vision Direct, alongside sharper-edged startups like Perfect Play, Beamery, Handshake (US), Peerpoint, Leakbot and Ordo Pay.
Prototypes, interactions and the tiny details, pulled from years of shipped work. They start playing as you scroll — no clicking required.
I love Coffee, Chess, Gym Training, Cooking good food, Investing & Architecture







Taking on 1–2 engagements per quarter — contract or fractional, US & UK. From research and prototyping through to shipped, revenue-critical UI. GMT, full morning overlap with EST.
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