The Problem
A German HR-tech company's multi-tenant SaaS application suffered a catastrophic database corruption event after a botched migration script accidentally deleted foreign key constraints across 47 tenant schemas. 380 active business customers lost access to their payroll and employee records overnight. The company faced potential regulatory fines under GDPR and contractual SLA penalties totalling over €180,000.
The Challenge
The database had no point-in-time recovery configured — only weekly snapshots, meaning up to 6 days of transactional data was at risk. The multi-tenant architecture used separate schemas per tenant (not separate databases), making selective restoration extremely complex. The migration script had run inside a transaction but committed before the rollback threshold was reached, making standard rollback impossible.
Our Solution
We assembled an emergency response team and worked through 3 phases over 36 hours:
• Phase 1 (Hours 0–8): Forensic binary log analysis to reconstruct all committed transactions since the last snapshot
• Phase 2 (Hours 8–24): Wrote a custom PHP/artisan script to replay 6 days of binlog events selectively across all 47 schemas, validating referential integrity after each batch
• Phase 3 (Hours 24–36): Re-applied all foreign key constraints, ran full data integrity checks, restored application access tenant by tenant with zero-impact to already-recovered tenants
• Simultaneously configured AWS RDS point-in-time recovery (PITR) to ensure this scenario can never reoccur
• Phase 1 (Hours 0–8): Forensic binary log analysis to reconstruct all committed transactions since the last snapshot
• Phase 2 (Hours 8–24): Wrote a custom PHP/artisan script to replay 6 days of binlog events selectively across all 47 schemas, validating referential integrity after each batch
• Phase 3 (Hours 24–36): Re-applied all foreign key constraints, ran full data integrity checks, restored application access tenant by tenant with zero-impact to already-recovered tenants
• Simultaneously configured AWS RDS point-in-time recovery (PITR) to ensure this scenario can never reoccur
The Result
100% of data was recovered for all 47 tenants with zero data loss. All tenants were back online within 36 hours. The company avoided all projected SLA penalties. We additionally delivered a post-mortem report and implemented automated daily backups with 30-day PITR, a schema migration review process, and pre-migration dry-run checks via artisan migrate --pretend in CI.