RoxanaCastillo

Architecture · LTI 1.3 · corporate eLearning

One shared course catalog, with full tracking

Problem: many Moodle instances (subsidiaries, business units) had to consume the same courses from a central catalog —embedded, without copying the content or drifting out of version sync— and the business needed full tracking, not just the grade.

Approach: I designed a canonical catalog consumed over LTI 1.3 (enrol_lti): each client instance activates the courses it needs and launches them embedded, from a single content source. Since AGS only returns the grade, I extended the return path with web services to bring back completion, progress and time spent. Validated against two real Moodle instances and a 5.0 ↔ 5.1 version matrix.

Result: a single canonical catalog, designed to serve courses embedded from one source —avoiding content duplication and version drift— with full tracking centralized. Built within the SHIFT ecosystem (team effort).

Data · Production · SHIFT platform (team)

An analytics pipeline down for 541 days

Problem: a learning-analytics sync process (xAPI/LRS) had gone ~541 days without updating; activity data wasn't reaching the dashboards, with no visible errors.

Approach: I diagnosed the root cause —special characters aborting batches of 5,000 records due to the database encoding— and migrated the entire database to utf8mb4 with a reversible migration; then reprocessed the missing history idempotently.

Result: +13,000 activity records reincorporated, with no duplicates, and the pipeline back up to date.

Integration · OAuth/OIDC · sole author

LTI 1.3: content that just works in any LMS

Problem: the platform had to launch embedded from any standard LMS (Moodle, Canvas, Blackboard) with the user's identity already resolved and securely.

Approach: I built the provider-side integration: OIDC-over-OAuth 2.0 launch validation verifying the signed JWT against the LMS JWKS, Deep Linking 2.0 to return content to the course, multi-tenant platform auto-registration, and session isolation in cross-site iframes (SameSite=None; Secure).

Result: SHIFT launchable as an LTI 1.3 tool from any compatible LMS, returning the selected content to the course. The integration is my own work; the platform is a team effort.

ltijs / Node.js · OAuth 2.0 / OIDC · JWT / JWKS · Deep Linking 2.0

Hard bug · Data · sole author (Time Tracker)

Silent corruption: recovering 100% of the data

Problem: a collaborator reported tasks that wouldn't list their project; on investigation, a sync process was deleting valid associations on every run — silently, with not a single error in the log.

Approach: root cause: the sync treated the external API as the sole source of truth and overwrote the association with null on transient failures. Non-destructive fix (preserve-on-null + skip PRs) and deterministic recovery from an alternative source of truth (title prefix → mapping table), with dry-run, JSON backup, and idempotent UPDATE.

Result: 301 associations —100% of the affected task bank (60 → 0)— leaving genuinely project-less issues intact. Internal tool; presented at capability level.