WhatsTheDx / A daily product loop

WhatsTheDx: building a reason to return.

A daily diagnosis challenge that turns a clinical question into an interactive product for professionals and students.

WhatsTheDx showing its daily diagnosis introduction and an interactive sample case with progressive clues.Open the live WhatsTheDx experience in a new tab
Public homepage and sample case · Captured October 2, 2026. The live product may change.
Eugene Huang · Product case study · October 2, 2026How we report product evidence ↗

The problem worth solving

For healthcare professionals and students

Professionals and students need a manageable way to practice reasoning. WhatsTheDx packages that need into a daily task: inspect the available information, choose an answer, and continue as the case unfolds. The product gives a useful activity a clear beginning and end.

The product decisions

01Let information arrive in stages

In Hard mode, a wrong guess or a skip reveals another clue. The learner can reconsider an interpretation as more information becomes available.

02Offer more than one way into the case

The product includes free-text guessing and an easier multiple-choice mode. Today's cases can be explored before creating an account.

03Give repeat practice a place

Daily cases, an archive, and account history organize the experience beyond a single visit. A saved record lets learners revisit earlier cases alongside the new daily challenge.

Inspect these features in WhatsTheDx ↗

What the evidence shows

1,100+sign-ups across a global community

More than 1,100 sign-ups, with practicing healthcare professionals and students around the world in the community.

Founder-reported on October 2, 2026. The figure describes cumulative sign-ups, not active users, verified professional credentials, or measured learning gains.

The capability this demonstrates

Taking a specific audience need, turning it into a working interaction, and bringing the product to a global community. Sign-ups show reach; repeat use and learning outcomes would need separate measurement.

The lesson for your next product

Start with one useful action a person can finish in a short visit. Build the complete loop around it: a starting point, a decision, feedback, and a next step. Add accounts and an archive when they support that loop. For your own product, measure completed sessions and return visits separately from registrations.

My building workflow has evolved from MVPs with Lovable, Cursor, and Windsurf to Claude Code and ChatGPT Astra with skills. Choosing an AI assistant is one decision; choosing the tools that build and run your app is another. Explore the roles of Vite, Next.js, and backend services →

Suggested exercise

Try a small version with AI.

Use this brief to explore the product pattern in a prototype of your own. This suggested exercise adapts the interaction in WhatsTheDx into a small, reviewable build.

A brief to adapt

Build a single-case prototype from a supplied, reviewed case. Show one clue at a time, accept a guess, and reveal the next clue after a wrong answer or skip. Keep the answer and explanation fixed to the supplied content. Include an obvious restart action and a finished state. Use sample data only.

Check the result with a person.

  • Check a correct guess, a wrong guess, a skip, and the final clue without an answer.
  • Confirm the interface does not reveal the answer early or alter the reviewed explanation.
  • Complete the whole case using a keyboard and on a small screen.

For the educational content in your prototype: build an interactive case presentation →