Zichen (Danny) Zhao

Researched a fundamental problem in LLM personalization: the signals we use to retrieve user context often don't predict what actually helps the model perform better downstream. We developed PURPLE, a framework that reframes personalization as a set generation problem and trains a ranking policy using likelihood-based feedback to capture how user records interact with each other. It consistently outperformed all baselines across nine personalization tasks spanning classification, regression, and text generation. The paper was accepted at ACL 2026.

Built and shipped a full-stack iOS platform to solve a real problem at my high school: club management was a mess of spreadsheets and WeChat groups. PH Clubs replaced all of it. By the time I graduated, the app was serving 580+ students across 210+ clubs, with role-based interfaces built separately for students, presidents, and teachers. Over three years, I iterated continuously based on real user feedback, shipping progressively more sophisticated functionality while keeping the experience seamless for a non-technical user base. Security, performance, and reliability were built into the architecture from the start. Available on the App Store.

Managing a calendar is more than creating events. Rescheduling, deleting, reorganizing, chaining multiple commands at once — it's constant low-value friction that adds up across a week. ChronosAI is a browser extension that acts as a full calendar secretary. Tell it what you need in natural language or voice — create, move, delete, or chain complex sequences of commands — and it handles everything in under a second. Event management time cut by around 80%. The deliberate decision was to build it with zero server-side storage. Your data never leaves your device. In a space where most tools quietly collect everything, that felt like the right call.

Co-founded a social enterprise at LaunchX connecting individuals with disabilities to specialized assistive equipment and services, bridging Chinese and Western assistive technology markets. Validated product-market fit through 50+ interviews with medical professionals, secured affiliate partnerships with healthcare vendors, and grew our online presence to 95K views and 3K+ followers while pursuing NGO registration.

Spent a summer at USC working with Prof. Cosimo Arnesano on production scheduling under stochastic demand, where operations management decisions carry real mathematical weight. Led a team of three. We built multi-period capacity planning models with rolling-horizon demand forecasts, then stress-tested them through Monte Carlo simulation across correlated forecast scenarios. The recommended policy projected a 26% profit improvement over the baseline. It was my first real taste of what applied research looks like when the output has to hold up under scrutiny.

Recipient of the Tahnoon bin Zayed AI Excellence Scholarship and full merit Pioneer scholarship.