Senior product designer
I’m Jay Park. I’ve worked on healthcare, SaaS, payments, marketplaces, and games. Each page below walks through the decisions behind the work.
I also build. Peptide Library is a native iOS app I designed, built, and shipped to the App Store.
01 Riot Games / League of LegendsShipped
I wrote the Challenges rules and designed the tab, lobby, loading screen, and end-of-game screens. Progress updates on its own.
League Challenges
The client is above. These diagrams are how the rules were framed.
Current state
Six records already existed. None of them was an account-level language for the whole game.
The ladder, not the rest of play.
Time, not the accomplishment.
Stays on that champion.
Stats that stay on that champion.
The record ends with the event.
Ownership, not what the player did.
The gap
No consistent account-level language for different kinds of accomplishment, from the lobby through the end of the game.
Opportunity
A shared recognition framework, while each of these systems keeps its purpose. Challenges does not replace Ranked, Mastery, or Eternals.
Before Challenges
A normal session, before a shared recognition layer. This is still the problem.
Activity
Reviews separate records.
Joins friends or teammates.
Sees the other players.
Plays the game.
Reads the result.
Chooses the next game.
Signals
Six systems, each apart.
Rank, level, and champion.
Champion, rank, and identity.
The match. Winning is the point.
The outcome, and separate updates.
The same separate records.
Missing
No shared account-level reading.
No shared frame for the rest of play.
No single accomplishment story.
Accomplishments happen here.
Updates do not share one language.
No single place to keep looking.
Opportunity
One reading, beside them.
Identity beyond rank.
Distinct from the champion.
Do not fight the win.
One read after the match.
Without starting a challenge.
The rules
The existing languages stay. A challenge has to pass a set of rules, then the same recognition shows up in four places.
Ranked
Keeps competitive placement.
Summoner Level
Keeps account activity.
Mastery
Keeps one champion.
Eternals
Keeps champion accomplishments.
Events and Missions
Keeps limited-time objectives.
Collection
Keeps owned content.
Scope
Account-level, or it stays with Mastery and Eternals.
Champion-specific goes back to Mastery and Eternals.
Category
The framework lists Legacy, Innovation, Skill, Teamwork, Collection, Seasonal, and Archived, while the shipped tab scores five and keeps Legacy apart.
Type
One-Shot, Accumulator, or Endless.
Grandmaster and Challenger only for Endless.
Competitive integrity
The goal cannot work against winning.
Deliberate losing is rejected.
Difficulty
A higher rank is more of the same. Top 25% and top 5% are design targets.
Reward
Token, Challenge Score, title, or another rank reward. Titles at Platinum, tabards at Master, seasonal Battle Pass XP.
State
Evergreen, seasonal, or no longer progressable.
Seasonal can become Archived.
Presentation
The card, then the tooltip, then the detail view.
Challenges tab
Categories, cards, and progress.
Lobby
Equipped title, up to three tokens, and the profile emblem.
Loading screen
Player information, separate from Mastery and Eternals.
End of game
What moved during that match.
02 / 03 FavoritedExploration
I worked through identity and gifting in design explorations. These screens did not ship.
Senior Product Designer (Contract)
04 Peptide LibraryLive on the App Store
An independent research and reflection app. I defined it, designed it, built it, and took it through device QA and App Store submission.
Build record
18 commits through Sep 16. 14 were co-authored with Cursor. I checked changes on the running app on device as I went.
Interactive prototype A web sample of the app
Explore
Phone recreation
05 MonkeyTiltShipped
On the level-up screen, a badge is for the player and Crew Boost +5% is the rule drawn for the crew.
Senior Product Designer (Contractor)
I led five concepts to one hero screen.
Senior Product Designer
I designed Blankos while the product direction was still open.
Senior UX Designer
Crafting had to improve inside the old build.
UX Designer
How I work
I start with the constraint, then the alternatives, then the decision. I stay with what the screen has to make clear, and with what engineering can ship.
When feedback changes the work, I keep that change on the page.
Product design & UX
At Riot I wrote the Challenges rules first: scope, category, type, competitive integrity, difficulty, reward, state, and presentation. The four screens show them.
League ChallengesVisual & interaction design
In Peptide Library, category marks, compound vials, and the app icon each follow their own rules. In the Favorited gifting exploration, active, near-complete, and complete are states of the same object.
Peptide visual systemAI-assisted build
I worked in the native Peptide build and kept the product calls, with Cursor as a co-author. I checked changes on the running app on device as I went. The reel at the top is code too, built in Remotion.
How I design and buildGood work starts
with a conversation.
