The Biggest Red Flag in Your Codebase
If your codebase depends on one person who knows everything, you are in deep, deep trouble my friend. This is a major red flag, a full-blown crisis waiting to happen. A healthy project does not rely on a single brain to function. It thrives on collaboration, shared knowledge, and systems that work even when people move on. The moment you let someone become the "sole expert" on a part of the codebase, you are setting your project up to fail.
This is how it happens. Over time, developers gravitate toward certain areas of the code. They write the features, fix the bugs, and before long, they are the only ones who understand that part of the system. It starts innocently enough. Maybe they are just good at it. But as time goes on, that expertise turns into a bottleneck. The team depends on them for every little thing related to that part of the codebase. They become the go-to person, the only one who knows what is going on, and suddenly the entire team's velocity is chained to their availability.
When they leave, you are stuck. What they leave behind is a mess of forgotten decisions and cryptic logic that no one else can figure out. This is catastrophic. Every decision has to wait until someone deciphers the mystery of what this person did and why they did it. The project stalls. Deadlines slip. Morale drops.
Why This Happens
The reason this happens is simple. Most teams do not prioritize distributing knowledge. They reward individuals for being the "expert" instead of making sure knowledge is shared. People assume their decisions are obvious or self-explanatory, so they skip documentation. They think their code is "simple enough" to understand without explanation. It is not. Even when they have good intentions, the task of documenting everything "later" never actually happens. What you are left with is a fragile, people-dependent system instead of a robust, self-sufficient one.
How to Fix It
Fixing this problem requires a shift in mindset. You cannot build a successful codebase around individuals. You have to build it around processes. First, document everything. Not just the code, but the decisions behind it. Why does this feature exist? What problem does it solve? What constraints were considered? Assume nothing is obvious, because in all likelihood, it is not. If someone new cannot onboard and understand the system without asking questions, your documentation is not good enough. Stop leaving things unsaid. Write it down.
Rotate Developers
Do not allow people to become entrenched in one part of the codebase. Rotate developers regularly. Let everyone work on different areas so that knowledge is distributed across the team. You need to make sure that no one is irreplaceable. If someone leaves tomorrow, the team should be able to pick up where they left off without missing a beat. This cross-pollination of expertise prevents operational bottlenecks and strengthens the team overall.
Centralize Conversations
Conversations and decisions must be centralized. Forget about Slack messages and quick verbal updates. Every discussion needs to be logged where the entire team can access it, query it simply. Use ticketing systems or discussion threads to preserve context. That way, new hires can read through the history and understand why things are the way they are instead of wasting time chasing down answers from people who might not even remember the details.
The Cost of Knowledge Hoarding
A codebase that depends on one person comes with a massive cost. Onboarding people becomes a nightmare because no one knows how the system works anymore. Every day a new hire spends "trying to understand" is a day you are paying salaries without getting progress. Simple tasks that should take days stretch into weeks or months. The codebase itself starts to rot because the people maintaining it assume "everyone knows this," when in reality they are the only ones who do. These are MONTHS of wasted payroll and lost momentum.
Automation and Self-Sufficiency
The solution to all of this is automation and self-sufficiency. Your codebase should be self-explanatory. Your processes should be automated. Your documentation should answer every question before it is asked. When you set up your project this way, onboarding becomes trivial. Developers can jump in, understand the system, and start contributing immediately. That is how you build a project that scales. That is how you build a project that survives without constant firefighting.
Stop relying on knowledge hoarders. Stop letting your project hinge on a single person's expertise. Document your decisions, rotate your teams, centralize your discussions, and automate as much as possible. If you let one person "own" the codebase, they now own you.