Summary
Working memory holds only what is being processed right now.
Capacity is limited. Rehearsal keeps it longer.
Interference pushes out what was there.
Product + UI/UX
Profile
02
CramAI
03–11
Frame by Frame
12
AI-Powered Audience Insights
13–14
Making
University Road Wayfinding
15
YIPENG ZHANG
2026
PROFILE
Yipeng Zhang
02
Product Engineer
Yipeng Zhang / 张逸鹏
Product Engineer · currently building CramAI
Product definition
UI/UX
Frontend
AI integration
Next.js
React
Multi-agent productization
I started in UI/UX and frontend, and now also own product definition and engineering delivery. I am currently building CramAI, turning multi-agent AI into a loop people can study, test, and track.
PRODUCT ENGINEERING
CramAI
03
Flagship · Dec 2025–present
CramAI
Multi-agent AI learning assistant
Problem
Study materials, practice, and tracking do not share one path.
Role
Product lead. I set direction and built the interface, frontend, and these path states.
Agents, variant generation, retrieval, and cloud infrastructure were owned by teammates.
1,264
Active users in 90 days
22,514
Product events
GA4 aggregate usage signal, Jun 7–Sep 4 2026. Not a growth, retention, or conversion-lift claim.
PRODUCT ENGINEERING
CramAI
04
Try it, then register, then pay
Guests get 3 tutor messages a day. Flashcards, quizzes, and published mock exams open after registration. Podcasts, posters, and web search are paid.
TryRegisterPay
FeatureGuestFreePro
Chat / day310200
Summary / day1350
Mind map / day1350
Flashcards / day—350
Quiz / day—350
Study plan / day—120
Mock exam / month—110
Wrong-answer scan / day—2Unlimited
Podcast, poster / month——30
Web searchOffOffOn
Counts come from the product entitlement table. Max removes these caps. Guests also get a separate 12-question mock that does not use the monthly exam quota. See 05.
PRODUCT ENGINEERING
CramAI
05
Value before login
Rejected
A full-page login wall.
Chose
Enter silently. Register after the exam.
01Silent entry
02Answers stay off the screen
03Register after grading
On the paper: type size, highlights, and striking out options.
PRODUCT ENGINEERING
CramAI
06
The toolbox opens in AI Tutor
Rejected
Summaries, flashcards, and quizzes each open a door.
Chose
Toolbox outputs stay in the same conversation.
AI Tutor
Study plan
View materials
Hi! I'm your AI study assistant. Based on working-memory.pdf, what would you like to know?
Make a summary of this material, and a set of flashcards.
Both outputs hang on the current material, in this same conversation.
Flashcards
Question
What pushes working memory out?
Click to flip
1 / 4
working-memory.pdf
Working memory
Working memory holds only what you are using, and does not store it for long.
Capacity is small, often just a few items. Rehearsal keeps a trace longer.
When something new interrupts, the old trace gets pushed out.
01Current material
02Outputs in the same session
PRODUCT ENGINEERING
CramAI
07
Papers arrange. Questions are entities.
Rejected
One demo JSON.
Chose
Papers only order items. Questions live on their own.
Demo JSON
→
Paper
Order
Question
PRODUCT ENGINEERING
CramAI
08
Question bank database
This picture is how an exam is stored. A category holds programs and tracks. A paper only orders questions. Questions are reusable entities. Knowledge points are one tree, attached to questions, not copied for every track.
Layers in the bank
The knowledge tree is separate from tracks. Learners still pick from a list.
LayerWhat it does
CategoryGroups exams
ProgramOne exam
TrackLevel, or national vs provincial
PaperOrders the questions
QuestionA reusable entity
Knowledge pointOne tree, attached to questions
The public library reads category, program, track, then paper. Solid lines are foreign keys. Dashed lines are not.
PRODUCT ENGINEERING
CramAI
09
Three rungs. Original stems stay hidden.
Learners see variants. A miss does not end the round. Two misses on the last rung hand the previous scaffold back.
The syllabus is stored once. Tags are not approved yet, so learners still pick from a list, not a tree.
PRODUCT ENGINEERING
CramAI
10
A hinted correct is not mastery
Mastery takes two consecutive zero-hint passes. The second is harder.
L1 Orient
L2 Method
L3 Step
Confirmation, one band up
Seeing a hint, then answering correctly, is not mastery.
PRODUCT ENGINEERING
CramAI
11
90-day product tree
Plausible, Jun 30–Sep 27, 2026. Signup conversion is unique visitors. Brighter green means more visitors: China first, then the US.
Visitors by place
CN 509
US 235
HK 126
SG 112
TW 35
JP 33
IN 25
PH 18
MY 7
FR 6
3.2%
Signup conversion
What they did
CTA click443
Guest gate315
Guest dashboard156
Landing view110
WEBSITE DESIGN
Frame by Frame
12
UI / Web · Apr 2025
Frame by Frame
A mosaic site that lets people switch art styles on their own photos
Problem
Art styles stay vocabulary until people can try them. This site turns an uploaded photo into Pop Art, Impressionist, or Cubist mosaics, with artwork metadata and live comments on the same interface.
Role
Team project. I owned the UI prototype, frontend integration, and mosaic.js refactor so style switching, carousel, and comments share one interface.
01
Miro
Collapsed interaction goals and style choice into one visitor path.
02
Figma prototype
Turned upload, style switching, artwork info, and comments into a clickable UI.
03
Frontend integration
Refactored mosaic.js so heavy tile loads still allow style switching and comments.
Live UI: upload a photo, switch art styles, read artwork info and comments.
WEBSITE DESIGN
AI-Powered Audience Insights
13
Academic system · Aug 2025
AI-Powered Audience Insights
From YouTube comments to content strategy
This project builds an AI tool that helps content creators by analysing audience feedback, filtering toxic comments, and generating useful ideas from user comments. Sentiment analysis and keyword grouping turn real opinions into strategies you can act on.
The system supports trend analysis across multiple videos and ongoing AI conversations. It uses RAKE, KeyBERT, and a locally deployed Llama 3 model rather than platform vanity metrics alone.
System overview — comment analysis to strategy suggestion.
WEBSITE DESIGN
AI-Powered Audience Insights
14
System and final website
Dashboard — channel performance and key metrics.
Trend Explorer — emerging topics across videos.
Video analysis — sentiment, keywords, and comment breakdown.
WAYFINDING DESIGN
University Road Wayfinding
15
Shipped spatial work · Jan 2024
University Road Wayfinding
Yangpu District, Shanghai
A wayfinding system for University Road around the Knowledge & Innovation Community. High-contrast color, modular structures, and night illumination — short proof of work that left the screen and was installed on the street.
Freestanding directional signs.
Overhead gantry, night view.