Software Anti-Patterns & Design Pattern Misuse
Common software design anti-patterns, misuse of design patterns, code smells indicating trouble, and refactoring strategies to fix them.
Common software anti-patterns and design-pattern misuse with aliases, symptoms, root cause, consequences, refactoring and related patterns: God Object, Singleton overuse, spaghetti code, golden hammer, premature optimization, copy-paste programming, lava flow and big ball of mud.
Use it when
- You are reviewing code or architecture for design problems.
- You need the vocabulary for a code-review comment.
Watch out for
- Labeling code with an anti-pattern name is a judgment; explain the concrete problem it causes.
- Some anti-patterns are rational short-term choices under deadline pressure.
The data
Anti patterns
8 rows
| Name | Also known as | Symptoms | Root cause | Consequences | Refactoring | Related patterns | When genuinely needed | Prevention | Examples | Healthy approach |
|---|---|---|---|---|---|---|---|---|---|---|
| God Object | Blob, Cosmic Know-It-All |
| Failure to decompose domain logic, premature optimization centralization, or gradual feature creep without refactoring. |
| Identify cohesive groups of methods → Extract Class for each group → Extract Interface for contracts → Use Facade pattern to simplify API if needed → Apply Dependency Injection to decouple | Facade (bad when used to wrap a God Object instead of fixing it) | null | null | null | null |
| Singleton Overuse (Singletonitis) | null |
| Convenience of global access mistaken for good design, misunderstanding of when shared state is truly needed. |
| Replace Singleton with Dependency Injection → Inject dependencies via constructor → For truly single-instance needs, use DI container's singleton scope → Avoid global state accessor pattern | null | Logging framework, configuration manager (immutable after load), hardware interface (OS has one instance), thread pool manager | null | null | null |
| Spaghetti Code | null |
| Lack of design, deadline pressure, insufficient refactoring, or working in a language without structured programming support. |
| Extract Method religiously (every 5-10 lines) → Replace Conditionals with Strategy Pattern → Introduce layered architecture → Remove global state → Add unit tests as safety net during refactoring | null | null | Enforce cyclomatic complexity limits (CI gate: < 10 per method), mandatory code reviews, pair programming for complex features | null | null |
| Golden Hammer | Law of Instrument ("If all you have is a hammer, everything looks like a nail") |
| Team comfort zone, resume-driven development, over-generalization of past success, lack of diverse technical exposure. |
| Evaluate each problem independently → Document trade-off decisions → Use polyglot approach where justified → Invest in team technical diversity | null | null | null | Using microservices for a 3-page website, Event Sourcing for a CRUD app, Machine Learning when a simple rule suffices | null |
| Premature Optimization | null |
| Misapplication of "performance mindset", lack of profiling data, assumption-driven development. |
| Profile first, optimize second → Remove speculative complexity → Measure before/after → Apply Knuth's maxim: "Premature optimization is the root of all evil" | null | null | null | null | Design reasonable architecture upfront, implement simply, profile in production, optimize only measured bottlenecks |
| Copy-Paste Programming | null |
| Deadline pressure, laziness, lack of refactoring culture, inadequate code review, absence of abstraction skills. |
| Extract Method/Class for each duplicate → Parameterize variations → Template Method pattern for similar algorithms → Use code duplication detection tools (Simian, PMD-CPD) | null | null | CI gate with duplication threshold, code review requirement, pair programming for complex logic | null | null |
| Lava Flow | null |
| Rapid prototyping without cleanup, developer turnover without knowledge transfer, fear of removing unknown code. |
| Systematically identify dead code via code coverage tools → Remove confirmed dead code → Add tests for live code → Use version control history as safety net | null | null | Regular codebase cleanup sprints, enforce code coverage minimums, remove features entirely when deprecated | null | null |
| Big Ball of Mud | null |
| Organic growth without architectural oversight, no refactoring, short-term thinking, "just make it work" culture. |
| Strangler Fig pattern → Identify bounded contexts → Extract modules one by one → Define clear interfaces between modules → Add architectural tests to enforce boundaries | null | null | Architecture Decision Records (ADRs), architectural fitness functions, regular architecture reviews, CI-enforced module boundaries | null | null |
Fields
The shape of this dataset, read from the data itself: every column, its type and a real value. Agents can use this to plan a query without fetching the whole document.
| Section | Field | Type | Example |
|---|---|---|---|
| anti_patterns | name | string | God Object |
| anti_patterns | also_known_as | string | Blob, Cosmic Know-It-All |
| anti_patterns | symptoms | array | [4 items] |
| anti_patterns | root_cause | string | Failure to decompose domain logic, premature op… |
| anti_patterns | consequences | array | [4 items] |
| anti_patterns | refactoring | string | Identify cohesive groups of methods → Extract C… |
| anti_patterns | related_patterns | string | Facade (bad when used to wrap a God Object inst… |
| anti_patterns | when_genuinely_needed | string | Logging framework, configuration manager (immut… |
| anti_patterns | prevention | string | Enforce cyclomatic complexity limits (CI gate: … |
| anti_patterns | examples | string | Using microservices for a 3-page website, Event… |
| anti_patterns | healthy_approach | string | Design reasonable architecture upfront, impleme… |
Fetch the same bytes
The static files contain the same reference rows as the API, with no API rate limit. Live metadata, such as view counts, may differ. Use the API for content negotiation; use the static files for a cacheable snapshot.
curl "https://yjtoon.yunusemrevurgun.com/api/dataset/design-pattern-anti-patterns?format=toon"
const res = await fetch( "https://yjtoon.yunusemrevurgun.com/static-data/dataset/design-pattern-anti-patterns.toon" ); const toon = await res.text();
Rate limit: 120 requests per minute per IP, no key and no signup. API reference →