12 Toxic Coding Habits That Destroy Readability (And How to Avoid Them)

Splitting Microservices Per Table

A developer named Er Gou believes microservices should be isolated, so he creates a separate service for each database table, leading to a complex architecture, excessive RPC calls, and difficult deployment for newcomers.

Excessive Refactoring with Feature Flags

Er Gou adds a new flag to reduce RPC calls, but only enables it in the test environment, causing confusion when the flag is not turned on in production.

Writing Super‑Long Methods

He insists that methods longer than 1000 lines improve logic continuity, refusing to extract smaller functions, which makes the code hard to understand and maintain.

Deep Nesting of Control Structures

Er Gou nests if/try/catch blocks more than ten levels deep, claiming the code has no bugs, while newcomers find it incomprehensible.

Random Variable Naming

He uses names like

str1

,

list2

without business relevance, later forgetting their meanings.

Misleading or Wrong Comments

Er Gou deliberately writes incorrect comments, swaps them, or leaves them unchanged when the code changes, leading to confusion for anyone reading the code.

Copy‑Paste Coding

He frequently copies existing code blocks instead of refactoring, causing duplicated logic and making it hard for others to track changes.

Ignoring Design Documents

Although he writes detailed technical proposals, he rarely follows them during implementation, resulting in a mismatch between documentation and actual code.

No Logging

Confident in his code, Er Gou never adds logs; when a production issue occurs, the lack of logs makes debugging extremely difficult.

Overusing Fancy Frameworks for Simple Problems

He introduces heavyweight rule‑engine frameworks to solve trivial strategy‑pattern cases, adding unnecessary complexity.

Reinventing the Wheel

Instead of using proven libraries like Redisson for distributed locks, he implements his own solution with

SETNX

, which later causes problems.

Summary

These twelve practices dramatically reduce code readability and increase maintenance difficulty; developers should avoid them to write clean, maintainable software.