Rewrite or refactor?
How to safely move legacy apps to modern frameworks
We Will All End Up with Legacy
- No one plans for legacy
- Tech ages faster than business
- Teams change, frameworks die
Legacy ≠ exotic
Why Migrate at All?
• Security patches stop
• Modern builds = faster apps
• Abandoned libs = risk
• Tech debt grows interest
Rewrite vs Refactor - Decision Matrix
| Criteria | Rewrite (Big Bang) | Refactor (Incremental) |
|---|---|---|
| Feature freeze | Yes | No |
| Codebase size | Small / Medium | Medium / Large |
| Full UI redesign | Easier | Needs parity |
| Team seniority | Senior | Mixed / Junior |
| Unknown domain | Risky | Safer |
| Time-to market pressure | No | Yes |
| Security pressure | Yes | Slower fix |