CandleMe — from a QR scan to a living candle in one redirect

Converting a person standing in a salon, library, or event venue into a tracked, attributable digital participant traditionally requires app installation, registration, email confirmation, and a password — each step shedding a large fraction of participants. Meanwhile the businesses placing those QR codes need the opposite of anonymity: hierarchical roles, attribution of every signup to the exact link and person who generated it, and analytics that survive across devices.

The brief resolved to one question: how do you give an anonymous person a fully functional, attributable account the instant they scan a QR code — before they have told you anything about themselves — while preserving a complete organizational attribution chain for the business that placed the code?

We inverted the identity model. Accounts exist in three progressively hardened states — temporary, verified, permanent — so an anonymous scanner is authenticated, role-assigned, and attributed in the referral tree before typing a single character. Attribution is structural, not inferred: referral relationships are self-referencing foreign keys, so any member’s full downline is a recursive query.

One Next.js codebase serves two brands through host-based middleware: the IDDAS B2B platform (distributors, links, batches, analytics) and the CandleMe consumer PWA, each with its own trust model behind a JWT context discriminator. Scanning a code "ignites" a virtual candle rendered by a hand-written signed-distance-field fragment shader — chosen after a five-way rendering bake-off against Lottie, PixiJS, and Three.js — and controlled by real sensors: microphone RMS for blow-out, accelerometer for shake, gyroscope for tilt.

The hot path never touches React: sensor state and 15 shader uniforms live in refs and GPU memory, updated by two synchronized 60 fps loops. Monetization runs accrue-then-charge on Stripe — usage accumulates against a running balance and is charged only past a threshold, so micro-transactions never hit the card network.

The frictionless ideal holds in production: scan to meaningful experience in a single HTTP redirect, with idempotent scan handling, concurrency-safe sealing, and per-candle PWA manifests so each home-screen install deep-links to its own candle.

Both services deploy scale-to-zero on Google Cloud Run, with speculative module preloading and first-paint discipline ensuring cold infrastructure never produces a cold experience — a sustained 60 fps flame on mid-range mobile hardware with near-zero reconciliation cost.