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Progress lives in localStorage. Temporary quiz authorization lives in sessionStorage and disappears when the tab closes.
PRIVACY · BY ARCHITECTURE
Learn without an account. Compete with control.
The path, portfolio, and mock exams work without registration. In Club Quiz, a pseudonymous passkey is enough to compete; a social profile is linked only afterwards and only if you choose.
- We use no cookies—advertising or technical.
- Complete course progress remains in your browser.
- We do not send prompts, code, documents, or tool artifacts.
- The leaderboard shows only verified, moderated, consenting profiles.
LOCAL FIRST · AGGREGATE ONLY
What happens when you use the site
The architecture separates local learning, collective metrics, and the voluntary competitive challenge.
Strict APIs
The competitive API receives an anti-bot proof, passkey data, opaque answers, and timing—never prompts, code, or artifacts.
Cloudflare D1
Learning data is identity-free counters. The challenge creates a public-key credential, attempt, score, and receipt; a profile exists only if linked afterwards.
Community
Shows GitHub contributions and competitive results only after consent and moderation. There is no anonymous leaderboard.
DATA MAP · NO FINE PRINT
Data inventory
Privacy means specifying what exists, where, and why—not merely calling the product “private”.
| Data | Location | Purpose | Retention | Identity |
|---|---|---|---|---|
| Progress and results | Browser localStorage | Continue the course and build your portfolio | Until you delete it | Random local ID, never sent |
| Tool inputs | Tab memory | Generate the requested artifact | Until close or reload | None |
| Activity counters | D1, aggregated by day | Show community activity | Rolling 400-day cleanup | None |
| Closed choices and technical outcomes | D1, daily distributions | Detect course difficulty, quality, and demand | Rolling 400-day cleanup | No user, session, or individual attempt |
| Club Quiz passkey | D1: public key and hashed session token | Prevent repetition by credential and authenticate the attempt | Session up to 30 days; credential while the edition remains verifiable | Unpublished technical identifier |
| Anti-bot check | Cloudflare Turnstile: IP and transient technical signals | Reduce automation before creating or using the passkey | Per Turnstile policy; never copied to D1 | Creates no Club identity |
| Optional social profile | D1: provider, public subject, name, avatar, and URL | After completion, prove account control and attribute the leaderboard with permission | Until withdrawal or moderation; OAuth tokens are discarded | Profile chosen by the participant |
| Optional verified email and consent proof | Worker + D1: AES-GCM encrypted address; exact wording, version, language, purpose, source, and consent timestamps | Send LLM Engineering content, news, offers, events, and meetups only after a separate checkbox and one X lookup | Address until withdrawal; encrypted address and hash are erased on withdrawal. The minimal proof is kept for up to 3 years, then deleted | Bound to the chosen passkey and X profile |
| Competitive attempt | D1: assigned questions, opaque choices, timing, correctness, and score | Server scoring, repetition control, and signed receipt | While the edition and proof need to remain verifiable | Bound to passkey; bound to a profile only if published |
| Content authorship | GitHub and static manifest | Credit PRs, authors, and reviewers | Public GitHub history | Public GitHub profile |
| HTTP request | Cloudflare network | Deliver the site and protect the service | Per Cloudflare configuration and policy | Cloudflare processes network metadata |
Your controls
You can inspect, export, import, or delete progress from the portfolio. In Club Quiz, result publication and email communications are separate choices. You can withdraw the latter in one click: the encrypted address is erased immediately without changing your result.
Controller: José Luis Cases Lozano, editor of LLM Engineer Club. Legal basis for commercial email: your consent (GDPR Art. 6(1)(a) and Spanish LSSI Arts. 21 and 22). For access, rectification, erasure, objection, restriction, or portability: contacto@traderprofesional.com. You may also lodge a complaint with the Spanish Data Protection Agency (AEPD).
SCHEMA · ALLOWLIST · FAIL-SOFT
Code and decisions
Learning metrics remain aggregate-only. Club Quiz uses no cookies and stores no IP address, user-agent, password, application fingerprint, or OAuth token. The only possible email is the X-verified address obtained after explicit consent and encrypted before reaching D1. Without that checkbox, it is neither queried nor stored.
Last reviewed: August 22, 2026