Continuing legacy software (without a full rewrite)

Revenue-bearing legacy isn’t thrown away for aesthetics. Stabilize it, document the critical path, evolve in slices.

By Will Fortes · Fortes Tech

“Let’s rewrite from scratch” is tempting — and expensive. Old systems often carry business rules nobody remembers until a customer complains.

A lower-risk order

  1. Stabilize production (backup, access, minimal monitoring).
  2. Map flows that make money or create risk.
  3. Fix the current fire.
  4. Extract a new module beside it (strangler) when it helps.
  5. Rewrite only what clearly can’t handle load or change.

Quick answers

Can you continue without the original developer?

Yes, with access and patient discovery. Without access, step one is recovering control.

Want to apply this to your business?

About 30 minutes to align the problem and next step — no commitment.