Choosing help when the original developer is gone

When your original developer has moved on—whether they've left the company, stopped responding, or simply aren't available—you face a harder problem than hiring a developer from scratch. You're not starting fresh. Someone else's decisions, shortcuts, and design choices are already baked into your system. The person who built it knows its quirks; a replacement won't. This asymmetry matters more than you'd think, and it shapes which candidate is actually right for the job.

The core trade-off is this: do you prioritise someone who can hit the ground running with minimal handover, or someone who can afford the time to learn the system properly? Speed feels urgent. But hiring the wrong person because you wanted fast results often costs far more in rework, repeated bugs, and frustration.

Reading code written by someone else

Not all developers are equally good at stepping into inherited code. Some thrive on it; others struggle visibly. Ask candidates directly about their experience maintaining systems they didn't write. Don't just listen to whether they say yes—ask them to describe a specific example: what the codebase looked like, how they figured out what was happening, what slowed them down. A developer who mumbles or stays vague probably hasn't done much of this work.

The best candidates will ask you detailed questions about your system before agreeing to anything: what language it's written in, how old it is, whether there's documentation, who can explain the current setup. Indifference to these details is a warning sign. They should also be honest about whether they've worked in that particular language or framework before. "I've never touched Python, but I pick things up fast" is less useful than "I've spent two years maintaining legacy Node systems."

What handover actually requires

Your original developer leaving creates a knowledge gap that a new person must somehow cross. The size of that gap depends partly on how well the system is documented—but also on whether anyone on your team can walk the new developer through it. If no one can, you're asking them to reverse-engineer decisions made years ago with no context. That takes weeks, not days.

When you're comparing candidates, think about this concretely. Can your team spend an afternoon with the new developer explaining how things work? Can you give them access to old emails or design notes? Is there a running system they can test against? Candidates who want this kind of support and ask for it tend to be slower starters but more reliable long-term. Those who wave it away and promise to "just read the code" often hit walls and miss bugs they could have caught with clearer context.

Looking past the CV

Experience in the same technology stack matters—but not as much as you might think. A developer who has spent five years fixing bugs in legacy systems, even in a different language, often learns your system faster than someone who has only worked on greenfield projects in your exact tech stack. Pattern recognition across systems is a skill; learning "your specific codebase" is not.

Instead, weight these factors:

• Debugging approach. Ask how they'd track down a bug in an unfamiliar system. Someone who describes using logs, testing narrow cases, and building mental maps of code flow is more useful than someone who just describes trying random fixes.
• Patience with ambiguity. Inherited code is messy. Candidates who accept this and ask methodical questions tend to do better than those who immediately want to rewrite everything.
• Communication. They need to explain what they find and why, especially when the original developer isn't around to defend their choices. A developer who communicates poorly will isolate you in problems.
• Willingness to document. As they learn your system, they should be updating notes, adding comments, writing runbooks. This isn't busy work—it's the foundation for the next person who comes after them.

Getting real references

When you call references, ask specifically about times they've taken over maintenance of systems they didn't build. Don't just ask "Were they good?" Ask: "How long until they were shipping confident fixes? Were there early bugs they missed? Did they document what they learned?" You're trying to understand their actual pace and their habits with code they didn't write.

Finding the right person to step in when your original developer is gone is less about raw speed and more about honesty—on both sides—about what learning your system will really take. Verified specialists on Strove who focus on maintenance and bug-fixing can show you their track record with exactly this kind of handover work, making it easier to spot someone who's done it well before.