Hello, I'm Anny이예린.
I plan.
I design.
I build.
Before building, I validate the plan against user behaviour data.
- Interviewed consultants on site and analysed two months of Hotjar heatmaps before reworking the screen
- Tracked VoC and introduced a simulation of recommended treatment combinations
I turn complex data into an intuitive, brand-defining visual experience.
- Visualised six skin scores, once a plain text list, as a hexagonal radar graph
- Established it as the brand's main identity and a core UX element
I don't guess at performance bottlenecks; I measure them precisely and fix them.
- Split the LCP loading path into five stages and tracked the delay at each
- Pinpointed and fixed the CPU readback bottleneck that took 218.7 ms of a 243 ms frame
I find problems where the work happens
and solve them through product.Yerin Lee, Software Engineer.
Gaia Labs · 2024.11 – Present · Seoul
Selected Work
All ProjectsDERMA:CODE
Frontend- A consultation program that structures skin condition, which consultants used to explain from experience and intuition, into 28 metrics, with recommended treatments and expected results.
- Validated the recurring VoC “I want to see how I'll look after the treatment” with a two-week prototype and grew the 3D simulation into a full feature. It went on to become key marketing content.
- Found an anomaly in the AI diagnosis score distribution in the accumulated statistics, proposed a relative-metric correction, and carried it through to model retraining and a labelling tool.
Next.js 15 · React 19 · TypeScript · React Three Fiber · three.js · MediaPipe · TensorFlow.js · Konva · TanStack Query · Zustand · react-i18next · Tailwind 4
Derma:code Chart Library
Design & development- Built eight chart types directly with the Canvas API to implement the hexagonal radar's gradient, markers and sequenced animation, which existing libraries could not.
- Built the same chart in Canvas, SVG and Recharts to compare them, checked the cost of accessibility and retina support as well as performance, and then chose Canvas.
Canvas API · TypeScript · pnpm workspace · tsup (CJS+ESM) · Vitest · Storybook · GitHub Actions · GitHub Packages
CPE
Frontend- An internal operations system covering a clinic's real workflow from booking through consultation, treatment and payment.
- Visited the clinic to interview consultants, and redesigned the work that used to span several screens mid-consultation so it completes on one. Kept in V2.
- Reassessed the Next.js structure against the nature of an operations tool used after login, and proposed the switch to React + Vite.
V1 · Next.js 14 (App Router) · V2 · React 19 · Vite · react-router v7 · TypeScript 5.9 · Zustand · TanStack Query · Tailwind 4 · Storybook · Vitest · FSD
Waiting for 7000 Bus
Planning, design & development- Built after watching my grandmother spend more than five minutes every time finding the next bus on a paper timetable.
- Finds the nearest 7000-series bus right away from an arrival or departure time.
React · Vite · TypeScript · Zustand · Emotion
About
I understand the real workflow before planning the build.
Working in aesthetic dermatology, where business logic directly shapes the product, taught me that implementing features to a specification is not enough to make a product effective. Before development starts, I observe real workflows and listen to users. I define what is needed and why, turn those findings into clear requirements, and validate solutions with prototypes and usage data before building them into the product.
What matters most to me is building products that genuinely help the people using them—not technical implementation for its own sake.