That old system still works. Sort of. Here's how to keep it running while you plan for what comes next.
The Reality of Legacy
Every system becomes legacy eventually. The one we built three years ago is legacy to us now. The question isn't whether you have legacy systems—it's how you manage them.
Replacing everything at once is rarely feasible. It's expensive, disruptive, and risky. Most businesses need to keep the old system running while they figure out the path forward. That means maintenance.
Document What You Have
If the original developer is gone and no one wrote anything down, you're flying blind. Start by documenting what the system does, who uses it, and what breaks when it goes down. Even a simple document helps the next person—or the next developer you hire.
We've taken over maintenance for clients whose previous developer left. The first thing we do is map the system: databases, integrations, cron jobs, deployment process. It usually takes a few days. That documentation becomes the foundation for everything that follows.
Prioritize Fixes
Not every bug needs fixing. Not every feature request needs building. Categorize: critical (system down, data loss), important (workaround exists but it's painful), nice-to-have. Fix critical first. Important when you have capacity. Nice-to-have goes on a backlog that you might never get to—and that's okay.
Plan the Replacement
Maintenance buys time. Use it to plan. What would a replacement look like? What would it cost? What's the migration path? You don't have to do it tomorrow, but having a plan means you're not scrambling when the old system finally gives out or when a key person leaves.