Why it matters
Old software rarely fails loudly. It just gets more expensive every year.
Many business-critical applications have served well for a decade or more — and exactly that is the problem.
The original authors have moved on, the documentation is thin, and every change feels risky. Releases slow down,
new requirements pile up, and the people who still understand the system are the same people you cannot afford to lose.
The cost of grown software is mostly hidden. It shows up as features that take weeks instead of days, as a hiring problem because no one wants to maintain a stack from another era, and as outages that are hard to reproduce because no two parts of the system were built the same way.
The answer is rarely a dramatic rewrite from scratch. It is a deliberate, measured modernisation: keep the business knowledge, replace the brittle foundations, and give your teams a codebase they can move in again — confidently, and without holding their breath at every deployment.