Privacy Policy

Overview

Backend Study Games is a browser-based educational site. Games and the challenge remain usable without signing in. Search, the concept map, progress, and Review Mode also work without an account or payment.

Local-first learning and optional Google identity

Google is the only optional identity provider in V1.5. Signing in is offered only for private cross-device continuity; the site does not offer passwords, magic links, or another identity provider in this release.

The browser keeps a local-first full learning state: XP and game totals, completed games, best scores, immutable attempts, and detailed review material such as prompts, chosen and expected answers, explanations, concept tags, mastery counts, and timestamps. If you sign in and choose cloud continuity, this full learning state and review items may be stored in the site's Cloudflare D1 database.

The first import from a device requires confirmation before anything is uploaded. Merge behavior is local-first: compatible totals use maximum or union rules, event records use stable IDs, and newer review updates and deletion markers are preserved. A network, sync, or D1 failure never blocks learning and never replaces a valid local snapshot; the browser reports that sync is pending.

Readiness challenge

The Backend Readiness Challenge keeps the six individual answers in memory only while it scores the attempt. Individual answers are not stored, and individual challenge answers are not sent. Private challenge history contains only validated result summaries: version, total correct, tier, three dimension scores, recommended path, and completion time. A signed-in user's validated summary may also be stored in the private D1 challenge_attempts table. Challenge completion does not add game XP or mark a game complete.

Explicit public result sharing

Public sharing is explicit and opt-in. A public row contains only the tier, three dimension scores, and recommended path. It contains no identity, answers, review material, or raw public or revocation token. Public links remain until revoked.

Anonymous revocation credentials remain on the device that created the link. Signed-in owners may manage and revoke their shares from the account interface. Someone who loses an anonymous on-device revocation credential may no longer be able to revoke that link through the product.

Optional leaderboard submissions

If you submit a score, the site stores the game slug, display name, score, score metric, timestamp, and abuse-prevention hashes. Raw IP addresses are not stored. If optional rate limiting is enabled, Cloudflare KV may temporarily count submissions by game and hashed IP.

Search

Site search uses a static Pagefind index generated at build time. Search queries run in your browser and are not sent to a search server operated by this site.

Anonymous aggregate learning events

To understand whether the practice flow is useful, the site may send an enumerated anonymous aggregate event for approved learning, challenge, sharing, sign-in, sync, and return-visit steps. The endpoint accepts only a four-key funnel payload: event, optional gameSlug, optional pathId, and source.

The aggregate contains no identity, token, answer, score, or arbitrary metadata. It also excludes prompts and review content. Cloudflare D1 stores only daily counts by event, game, path, and source, not a record of an individual visit or a persistent visitor identifier.

When abuse control is configured, Cloudflare KV may temporarily count hashed request sources. That temporary count helps limit automated requests and is not a persistent visitor identifier.

Ads, cookies, and analytics

The approved active Google AdSense loader is included sitewide. V1.5 adds no real ad units, and learning is never gated by ads. Game commercial regions remain after the playable region and completion continuation. The site does not use a separate analytics SDK for the anonymous aggregate learning events described above.

Google AdSense or another ad provider may use cookies or similar technologies to serve ads, limit repeated ads, measure performance, detect invalid traffic, and, where allowed, personalize ads. Google and its partners may use advertising cookies based on your visit to this and other sites.

Visitors can learn more about Google advertising choices at Google's advertising technologies page. If ads are shown to visitors in regions that require consent, such as the EEA, UK, or Switzerland, the site should display a consent flow before personalized advertising is used.

Account export and deletion

A signed-in user may download an account export containing learning data, validated challenge history, and owned share metadata. The export excludes session credentials, provider tokens, and share revocation secrets.

Account deletion requires an explicit confirmation. It removes the account's cloud learning and review data, challenge history, owned shares, provider account rows, verification records, and authentication sessions in one database batch, then clears the browser session cookie. Owned shares are removed rather than left public. Anonymous aggregate daily counts remain because they cannot be traced to an account. Local learning in the current browser is not erased.

Leaderboard removal requests

Contact [email protected] to request removal of a submitted leaderboard score. Include the game name, display name, approximate timestamp, and score so the row can be located.

Payments

There are no payments or subscriptions in V1.5.