A federated SSO hub for cross-tenant account linking
Designed a centralized hub that lets users link accounts across independent tenants using union-find transitive closure and HMAC-signed JWT flows.
2025 architecture
Work
Case studies from my work as a Product Engineer at Digiicampus — a multi-tenant platform for educational institutions. Each write-up covers the problem, the approach, and the measurable outcome.
FF1 format-preserving encryption for ID obfuscation
Replaced sequential integer IDs across a multi-tenant platform with FF1-encrypted equivalents to prevent enumeration attacks — without breaking schemas or queries.
2025 security
Selfie attendance with geofencing and server-side time enforcement
Built a biometric attendance flow with geofenced locations, multi-layer timezone resolution, and server-side timestamp enforcement to prevent device-time fraud.
2025 feature
Cutting $3,400/year from ElastiCache with a cluster-wide audit
Audited 15+ Redis clusters, upgraded from 6.2.6 to 7.1.0 to avoid Extended Support fees, right-sized instances based on actual usage, and fixed cache anti-patterns in application code.
Q1 2025 infra