Years shipping digital products
Profile / Sebastien Marchi
SEB MARSA.K.A. SEB
A senior product designer, founder, inventor and full-stack builder working where ambitious ideas become coherent systems.
The person behind the signal
THE PERSON
BEHIND THE SIGNAL.
Senior Product Designer · Founder · Inventor · Full-stack builder
I turn complex products and ambitious ideas into systems people can understand, trust and use.
Montréal, QuébecOpen to remote collaborationEnglish · French
Actual human · No simulation
Designer by craft.
Inventor by instinct.
Builder by necessity.
I’m Sebastien Marchi—SEB MARS—a Montréal-based senior product designer with more than eight years shipping marketplace, SaaS, platform and growth experiences. My practice connects product strategy, UX architecture, interaction design, branding and technology.
I work closest to difficult systems: products with multiple actors, unfamiliar ownership models, transactional complexity and ideas that do not yet have an established interface language. My job is to make that complexity feel coherent without making the idea ordinary.
Months to build FanFactors solo
Languages · French and English
End-to-end multidisciplinary practice
Professional experience
From ambiguity
to production.
012024—2025
FanFactors · Consumer marketplace platform
Senior Product Designer
Owned end-to-end product design across onboarding, purchase flows and post-purchase engagement for mobile and web.
- Activation and conversion experimentation
- Trust-driven transactional and ownership UX
- Production partnership with product and engineering
- Reusable component patterns and design systems
022019—2023
Myro Smart Web · Multi-surface commerce platform
Senior Product Designer
Led UX strategy and execution for a platform serving users, creators and small businesses across interconnected surfaces.
- Discovery, seller dashboards and buyer conversion
- Usability testing and iterative refinement
- Complex workflow and state design
- Multi-level roles and permissions
032016—2019
SEB MARS Digital · B2B and consumer products
Senior Product Design Consultant
Designed and shipped products across health, AI, e-commerce and SaaS for early-stage and growth-stage clients.
- Discovery through high-fidelity delivery
- MVP definition with founders and executives
- UX strategy, prototyping and validation
- Product direction aligned to business outcomes
05
Current build · Founder & Full-stack developer
FanFactors.
Designed and built.
In five months, I designed and built a functioning gamified music marketplace by directing AI coding agents from architecture through deployment. The platform includes authentication, media management, artist and seller dashboards, working payments and a new 33/33/33 ownership and resale model.
Next.jsReactSupabaseStripeTailwind CSSVercel
View the FanFactors case study ↗Operating range
One practice.
Eight capabilities.
Product design
0 → 1 → scale
Platform UX
Systems and architecture
Interaction design
High-fidelity execution
Research
Synthesis and usability
Prototyping
Experimentation and validation
Design systems
Figma and reusable patterns
Growth design
Activation and conversion
AI-directed development
From specification to production
How I work
See the system.
Find the signal.
Ship the proof.
Discover
Understand the human tension, product reality and business conditions beneath the request.
Architect
Turn complexity into a legible model of actors, states, journeys, information and value.
Prototype
Make the idea tangible early enough to test assumptions, interaction and emotional credibility.
Ship
Partner with engineering—or direct AI development—to carry the system into working production.
Education and certification
A practice built
by learning forward.
Usability Engineering & UX Research
Nielsen Norman Group
Human-Centered & Service Design
IDEO U
Product Design & UX Foundations
Google Certificates
Interaction Design & UX Principles
Interaction Design Foundation
Digital Marketing
Udacity
Multimedia & Graphic Design
LaSalle College
SEB MARS A.K.A. SEB
I don’t just design
what a product looks like.
I design what it becomes.
Available for senior product design, platform UX, product strategy and ambitious founder collaborations.
Start a conversation ↗Free illustrated Origin book
Before the signal,
there was Neave.
Recover Escape the Machine: Origin—30 cinematic pages revealing the first memory, the Machine and the world behind every Chronicle.
Free collector edition30 pages · 14 original scenes
Neave / The architect's horizon
The person becomes
the signal.
Experience, invention and unfinished questions converge into a practice built to make difficult futures tangible.
Enter the Neave Chronicles ↘