SAVE
InvestmentNewsPlatform
3 people, 100K DAU in 4 weeks — designing the fastest US stock news platform in Korea
Role
E2E UX Design
Duration
2025
Platform
Mobile · iOS / Android
Team
2 Engineers, 1 PM, 1 Designer (me)
Users
100K Daily Active Users
I owned every design surface — mobile UX, UI, onboarding, notification systems, marketing website, and app store presence. With a 3-person team, there was no handoff — I designed, prototyped, and worked directly with engineers through implementation.
Overview
Outcome Snapshot
What shipped, why it mattered, and how impact was measured.
With 3 people and no funding runway to spare, we built the fastest US stock news platform in Korea. I designed every user-facing surface — from the real-time news feed to the notification system to the marketing site that drove our launch. In 4 weeks, we hit 100K daily active users with a perfect 5.0 App Store rating.
Korean retail investors had exploded in 2024–2025, but existing news platforms had 5–10 minute delays from US sources, cluttered interfaces, and no personalization. A small team saw an opportunity to build the fastest, cleanest US stock news experience for Korean investors.
100K
DAU in 4 weeks
<30s
News latency (Korea's fastest)
5.0★
App Store rating
Challenge
5,000 Articles a Day, 3 That Matter
Korean retail investors trading US stocks faced a paradox: they were drowning in information but starving for the right information. Existing platforms dumped 5,000+ articles per day into chronological feeds. Users had to scroll through earnings reports, analyst opinions, macro news, and company updates to find the 3 articles actually relevant to their portfolio.
The timing problem made it worse. Korean market hours overlap with US pre-market and after-hours. By the time Korean platforms translated and published US news, retail investors were already 5–10 minutes behind institutional traders who read English sources directly.
- Latency Gap — 5–10 minute delays vs. US sources meant Korean retail investors were always trading on stale information
- Signal-to-Noise — 5,000+ articles/day with no filtering by portfolio, sector, or sentiment
- Language Barrier — Most high-quality US market analysis was English-only, creating a two-tier information market
Approach
Three Layers for Three Mindsets
I mapped how Korean investors actually consumed news across a trading day and identified three distinct mindsets: scanning (what's happening right now?), monitoring (what's relevant to my portfolio?), and planning (what's coming up?). Each mindset needed a different information architecture.
We considered a single-feed design with smart filtering, but user testing showed that investors mentally separate "breaking news" from "my watchlist" from "upcoming events." Forcing them into one timeline created anxiety. The three-tab structure matched their natural behavior.
- Breaking Feed — Chronological, unfiltered, <30s latency. For the scanning mindset: "what just happened?"
- Smart Alerts — Keyword and company-based notifications. For the monitoring mindset: "does this affect my portfolio?"
- Investment Calendar — Earnings dates, FOMC meetings, economic indicators. For the planning mindset: "what's coming?"
Impact
Week 1: 1K → Week 2: 10K → Week 4: 100K
Product-market fit was immediate. The combination of speed (fastest in Korea), relevance (smart filtering), and simplicity (clean, scannable cards) resonated with Korean investors who were tired of cluttered, slow alternatives. Word-of-mouth drove exponential growth — we did almost no paid marketing.
1K→100K
DAU in 4 weeks
5.0★
Perfect App Store rating
<30s
Fastest news latency in Korea
80%
Noise reduction via smart alerts
Reflection
Key Learnings
01
Speed is a Feature You Can Feel
The difference between 30-second and 5-minute news latency isn't just technical — it's emotional. Users told us SAVE "felt alive" compared to competitors. That feeling of real-time responsiveness drove retention more than any UI feature.
02
3-Person Team Means Every Decision is Final
With no bandwidth for iteration cycles, I had to get designs right the first time. That meant heavier upfront research, faster prototyping, and ruthless scope cuts. Every feature had to answer: can our 2 engineers build this in a week?
03
The Marketing Site is Part of the Product
Designing the marketing site alongside the product wasn't a side project — it was a strategic decision. The site's messaging and visual language set user expectations that the app immediately fulfilled, creating a seamless acquisition-to-activation funnel.
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