舊系統現代化與零停機時間重新平台化

We use a strangler fig pattern with dual-write data replication. The new Next.js frontend starts by consuming your legacy APIs while we migrate data to Supabase via CDC streams in the background. Traffic shifts progressively through CDN routing rules—5% canary, then ramp to 100% over a few weeks. By the time we flip DNS, both systems are fully synchronized, so the actual cutover takes minutes, not hours. Rollback is a single configuration change.

12-20 weeks, depending on monolith complexity, database size, and how many downstream integrations you're carrying. We kick things off with a 2-week paid discovery phase that produces a complete migration graph and risk assessment. The frontend and data migration workstreams run in parallel rather than sequentially—that's what compresses the overall timeline. You're not waiting for one phase to finish before the next one starts.

Automated reconciliation runs every 15 minutes, comparing row counts, aggregate checksums, and referential integrity across both the legacy database and Supabase. We don't flip the write path to Supabase until reconciliation has passed cleanly for 72 consecutive hours. After cutover, the legacy database stays in read-only mode for 30 days before decommission—it's there if we need it, but we've never had to use it.

Yes. We build a bridge layer that translates legacy session cookies to JWT tokens during the transition period. Supabase Auth supports JWT, OAuth2, SAML, and magic links natively. User credentials migrate with bcrypt-compatible hashing, so nobody gets logged out. The bridge typically runs for 2-4 weeks—long enough for all active sessions to naturally expire and re-authenticate against the new system.

Every integration point is controlled by feature flags, so nothing is binary. Rolling back the Next.js frontend to the legacy system is a CDN routing rule change that takes effect in under 60 seconds. Database rollback routes writes back to the legacy system via the reverse-replication stream. We test the complete rollback procedure in staging before every production cutover—it's not something we figure out on the night.

Typically 40-50% reduction in hosting and maintenance costs within the first year. Legacy monoliths need vertical scaling (bigger, more expensive servers), licensed databases (SQL Server, Oracle), and dedicated ops teams just to keep the lights on. The Jamstack architecture uses edge-distributed static assets, serverless compute that scales to zero when idle, and Supabase's managed PostgreSQL at elastic pricing. We model the projected numbers during discovery so you're not guessing.

No. The strangler fig pattern means we extract and modernize business logic incrementally—nothing moves all at once. Critical paths go to Supabase Edge Functions or Next.js API routes first. Low-risk legacy logic can keep running behind the API compatibility layer for months while we work through higher priorities. We sequence based on performance impact and maintenance burden, not some arbitrary definition of completeness.