Case study · 03 / 06
Lumen
Y Combinator W25
Mobile engineering, product design
A patient-side mobile app for tracking chronic symptoms across multiple care providers.
Year
2025
Duration
8 weeks
Type
Mobile App
Role
Mobile engineering, product design
Lumen — daily check-indrop final hero render here
01The challenge
What we were asked to solve.
Patients with chronic conditions juggled 4–6 portals, paper logs, and inconsistent advice. The founder needed an MVP polished enough to attract a clinical pilot, on a YC budget.
02The solution
What we shipped.
We shipped a SwiftUI + Kotlin Compose app sharing a typed schema and a small Rust core for symptom math. A clean weekly digest replaced four separate care-team emails.
solution screen · 4:3
03Tech stack
What it's built on.
SwiftKotlinRustSupabaseResend
04Results
What changed.
38%
DAU/MAU
4.8★
App Store
8 wks
MVP to launch
screen 01 · primary view
screen 02 · detail
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