How to Reduce Dependence on One Developer

The first step is an honest inventory, done while the developer in question is still available to help build it: which accounts, passwords, deployment steps and pieces of undocumented logic exist only in this one person's head or personal accounts. This is not a comfortable exercise, but it is far easier to do calmly, with the developer's cooperation, than to reconstruct after they have already left.

Imagine an interior design firm whose project-tracking and client-approval tool has been built and solely maintained by one in-house developer for six years. That developer likely knows dozens of small operational details — which server to restart when a particular batch job hangs, which client's data has a known quirk, how a specific integration was patched around a limitation — that exist nowhere except in their own memory. Getting even a rough version of that knowledge written down is the single highest-value step in this entire process.

A common and specific risk is that repositories, hosting, domains or API accounts were set up under the developer's personal login rather than a company-owned account — convenient at the time, but a serious single point of failure. Move every one of these into accounts the business itself owns and controls, with the developer given appropriate access as a team member rather than as the account holder.

This is worth treating as a checklist to close out completely rather than partially: source code repository, hosting or cloud provider, domain registrar, database, and every third-party API subscription the application depends on. A single overlooked account — a forgotten API key still billed to a personal card — can recreate the exact risk this whole exercise is meant to remove.

Documentation does not need to be exhaustive to be useful; it needs to cover what would otherwise only exist in one person's memory. At minimum: how the application is built and deployed from source code to a running system, where and how data is backed up and how a restore actually works, and what to do for the handful of recovery scenarios that come up most often — a failed deployment, a database issue, an expired certificate.

Write this documentation assuming the reader is a competent developer who has never seen this specific system before, not assuming institutional context they would only have if they already worked there. That standard — could someone new actually follow this — is the real test of whether the documentation is good enough.

Code review, even informal, is one of the most effective ways to reduce single-developer risk without adding much overhead, because it means at least one other person has looked at and understood any given change before it goes live — building a second person's familiarity with the codebase gradually, change by change, rather than all at once.

Shared ownership works the same way at a larger scale: rotating who handles which part of the system, pairing on more complex changes, or simply ensuring more than one person has genuinely worked in every major area of the codebase, rather than one developer effectively owning entire modules that no one else has ever touched.

The clearest test of whether dependence on one developer has actually been reduced is a rehearsal: have a second person — another team member, or an external contractor — deploy a change independently, using only the documentation and access that has been set up, without the primary developer's help. Any point where that person gets stuck reveals exactly what the plan missed.

This rehearsal is far more valuable done deliberately, on a calm schedule, than discovered for the first time during an actual emergency. Treating it as a routine exercise, repeated occasionally as the system changes, keeps the plan honest rather than letting it quietly go stale the way documentation often does.