Is inherited code a gift or a gamble?

Taking over an app you didn’t build? You’re not alone.

We hear it all the time: “We’ve inherited this code from another team” or “The original developer left, and now we’re just trying to keep it running”. For tech leaders trying to regain control of legacy mobile apps, taking over inherited code can feel more like damage control than development.

You want to keep moving forward. But right now, just understanding how the app works feels like a full-time job.

This is where inherited code becomes a real risk. Not because it’s old or ugly, but because the second something breaks, you’re the one left holding the bag. You can’t afford to guess how things work or cross your fingers every time you ship.

What you’re up against

Most legacy apps come with a few common headaches:

• Limited documentation
  •  Even if there was once a plan, it’s probably out of date. You’re stuck piecing things together from scattered comments, inconsistent patterns and guesswork. 
• No automated tests
  • Which means you’re testing by feel, or reacting to bugs after they hit production. 
• Outdated tools and frameworks
  • Old libraries, unsupported versions and brittle dependencies make even small changes risky. 
• High technical debt
  • Years of shortcuts add up. Quick fixes on top of quick fixes have left the code fragile and unpredictable. 

You don’t need a full rebuild. You need a way forward.

When you’ve inherited a codebase, a ground-up rewrite might feel tempting. But in most cases, it’s just not necessary. What you need is a pragmatic strategy to untangle the mess, stabilise the app and start making real progress again.

Here’s how we recommend tackling it:

• Start with a deep audit
  • Before touching a line of code, map out the architecture, dependencies and high-risk areas. This lets you plan changes with confidence. 
• Refactor in small steps
  • Don’t rip it up and start over. Clean up the worst parts first, fixing one thing at a time. Focus on the areas that break often or impact the business directly. Technically, every issue impacts the business, but focus on the critical bits in the first instance – such as service outages or issues stemming directly from user complaints.

• Update documentation as you go
  • Not the big polished kind, just clear internal records. Every insight helps the next person avoid a guess. 
• Bring in modern tools
  • Use static analysis and comprehensive testing frameworks to catch bugs earlier and build better habits moving forward.
     

There’s a way out of the mess

You might not have chosen this codebase, but it’s yours now. With the right approach, you can make it manageable again.

That’s what we do at Indiespring. We don’t default to rewrites. We help teams stabilise, document and move forward with confidence. So the next time something breaks, you won’t be starting from scratch.

Worried about what’s lurking in your inherited app? Let’s audit the risk and figure out where you need to start.

Let’s chat