6 Types of Bit Rot

John Spacey, updated on July 07, 2023

Bit rot is the reduction in quality of an instance of software that occurs over time. This can result in unstable, slow, inaccurate and inefficient software that is perceived as legacy. The following are common types of bit rot.

Data Rot

Physical errors in data that occur over time due to the error rate of devices. This can include the binary code of an instance of software and the data that the software uses.

Logical Errors

Logical errors in data due to software bugs, processing errors and other phenomena.

Robustness

Software components that handle errors poorly such that minor problems cause a large decline in software quality. As an extreme example, software that gives up loading 1 million customer records because it encounters a single field that is incorrectly formatted in a record.

Data Complexity

Data that grows in complexity with time due to the design of the software or the business processes it supports. This may expose bugs that don't appear in the software when data is simpler.

External Change

Change to factors such as hardware, APIs and environments.

Entropy

All isolated systems go from a state of order to a state of disorder over time in a process known as entropy.

Notes

Software that is regularly updated with new code, hardware and data isn't an isolated system that is necessarily subject to entropy.

Overview: Bit Rot
Type	Legacy Systems
Definition	The reduction in quality of an instance of software that occurs over time.
Also Known As	Software rot
Related Concepts	Legacy Systems » Data Rot » Data » Data Complexity » Software Design » API »