Coding standards, review practices, and clean room testing ensure that written code is correct, readable, and maintainable from day one.
📏 Coding Standards
Coding standards are a set of guidelines and best practices that developers must follow when writing code. They ensure consistency, readability, and maintainability across a codebase.
Naming Conventions
Use meaningful, descriptive variable names
Constants in UPPER_CASE
Classes in PascalCase
Functions/variables in camelCase
Avoid single-letter names (except loop counters)
Formatting Rules
Consistent indentation (spaces or tabs)
One statement per line
Limit line length (e.g., 80–120 chars)
Blank lines between logical sections
Braces on consistent positions
Documentation Standards
Every function should have a header comment (purpose, parameters, return value)
Complex logic should be explained inline
Avoid commenting the obvious (i++ // increment i)
Use standard formats like Javadoc, Doxygen
Golden Rule: Code is read far more often than it is written. Write for the next developer who will read it — even if that's future you.
🔍 Code Review
Code review is a systematic examination of source code intended to find bugs, improve quality, and ensure standards are followed. Three main types:
1. Code Walkthrough
An informal review led by the code's author. The author presents and explains the code to a small group of colleagues, who ask questions and identify potential issues.
Author leads the session
Informal — no strict rules
Goal: find bugs & share knowledge
Reviewers should prepare in advance
Not for fault-finding of the developer — focus on code quality
2. Code Inspection
A formal, structured review with defined roles, checklists, and procedures. More rigorous than walkthrough and statistically more effective at finding defects.
Role
Responsibility
Moderator
Leads the inspection, schedules meetings
Author
Answers questions, does not defend choices
Inspector
Reviews code, identifies defects using checklist
Scribe/Recorder
Documents defects found
Inspection Process Flow
Walkthrough vs Inspection
Aspect
Walkthrough
Inspection
Formality
Informal
Formal
Led by
Author
Moderator
Checklist
No
Yes
Defect logging
Informal
Formal records
Effectiveness
Moderate
High
🧹 Clean Room Testing
A software development methodology developed at IBM. Aims to produce software with the quality of cleanroom manufacturing — zero defects through rigorous formal specification and statistical testing.
Key Idea: Developers never execute the code they write during development. All testing is done by an independent testing team using statistical methods. The goal is to prevent defects, not find them.
Core Principles
Formal Specification: Code is derived from mathematical specs using correctness proofs
Incremental Development: Software is developed in small increments
Statistical Testing: Tests are based on usage probability — most-used paths tested most
Independent Testing: Separate team tests each increment
No unit debugging by developers: Developers rely on correctness verification, not debugging