# ashishps1/awesome-low-level-design architecture

> Architecture diagram of the GitHub repository ashishps1/awesome-low-level-design, generated by GitDiagram from its file tree, README and a sample of source files (last updated 2026-06-20). It is an AI-made overview: check details against the source.

- Interactive diagram: https://gitdiagram.com/ashishps1/awesome-low-level-design
- Repository: https://github.com/ashishps1/awesome-low-level-design

## Overview

1. This repository is an educational monorepo for Low Level Design / Object-Oriented Design. It is not a single product system; it is a collection of independent examples, interview problem prompts, and reference implementations.

2. The top-level boundary is content vs. code:
- `README.md` explains the learning path.
- `oop/` contains fundamentals of object modeling and relationships.
- `design-patterns/` contains pattern-specific demos.
- `problems/` contains problem statements/specs.
- `solutions/` contains concrete implementations of those problems in multiple languages.

3. The code is organized by language, and each language tree is effectively its own isolated architecture:
- `solutions/java`, `solutions/csharp`, `solutions/golang`, `solutions/python`, and `solutions/typescript`.
- Each language folder has the same conceptual systems, but no shared runtime or cross-language dependencies.
- Build tooling varies by language: Maven for Java, .NET projects for C#, Go modules, npm/TypeScript config, and plain Python modules.

4. Inside `design-patterns/`, the repository is split by pattern family:
- Creational, Structural, and Behavioral patterns.
- Each pattern folder is a self-contained demo with a small entrypoint and a few collaborating classes.
- The architecture is intentionally minimal: one pattern example per directory, designed to show object relationships rather than app-scale boundaries.

5. The repeated structural pattern across examples is: domain model + orchestration object + optional extension points.
- Domain models represent the core entities, such as `User`, `Order`, `Flight`, `Seat`, `Task`, `Message`, or `Player`.
- Orchestrators are named like `Service`, `System`, `Manager`, `Facade`, `Controller`, or `Demo`.
- Extension points are usually interfaces or abstract bases implementing Strategy, State, Observer, Factory, Command, Decorator, etc.

6. A major architectural theme is stateful workflows. Many systems model lifecycle transitions with explicit state classes:
- Examples include vending machines, booking systems, ride-sharing trips, tasks, orders, elevator motion, traffic signals, and game states.
- The state objects own allowed transitions and behavior, while the main system/context delegates to the current state.
- This keeps invalid transitions out of the core entity and makes state diagrams central to the design.

7. Another recurring boundary is policy vs. orchestration:
- Strategy implementations handle variable business rules such as pricing, search, matching, payment, shipping, sorting, or recommendation.
- The core service/system selects a strategy and delegates the decision logic to it.
- This is visible in systems like online shopping, movie ticket booking, ride-sharing, stock brokerage, logistics, and social/feed generation examples.

8. Observer/pub-sub style flows are used for notification and side effects:
- Subjects publish domain events such as new posts, orders, auctions, trips, matches, or score changes.
- Observers handle downstream reactions like notifications, scoreboards, logs, commentary, or reputation changes.
- This creates a clean split between state mutation and reactive listeners.

9. Composite and aggregation-heavy examples model trees and collections:
- File systems, organizations, playlists, menus, or nested domain structures are represented as parent/child hierarchies.
- The composite boundary lets leaf and container objects share a common interface.
- These examples are useful for diagramming recursive ownership and uniform traversal.

10. Several examples use command/facade/adapter to hide operational complexity:
- Command appears in UI, media, stock-trading, restaurant, or device control flows.
- Facade wraps multi-step processes like deployment, restaurant management, hotel booking, or movie playback.
- Adapter appears where an external or legacy interface is normalized to an internal contract, especially in payment examples.

11. The repository is mostly in-memory and console/demo driven:
- There is no central database, service mesh, or web frontend architecture.
- Most examples instantiate objects in a demo `main` / `Program` / `Demo` file, execute a workflow, and print results.
- That means architecture diagrams should focus on object collaboration and runtime flow, not external infrastructure.

12. Many solution sets are duplicated across languages with the same conceptual layout:
- A single problem often exists as parallel implementations in C++, C#, Go, Java, Python, and sometimes TypeScript.
- The class names and responsibilities are usually similar across languages even when syntax differs.
- This makes the repo best understood as a pattern-and-domain catalog rather than a single integrated system.

13. A good architecture diagram for this repo should therefore emphasize:
- the educational/documentation layer,
- the per-language solution boundaries,
- and, inside each example, the interaction between entity models, orchestration/services, and pluggable pattern objects.

14. The most important architectural takeaway is that the repo demonstrates reusable design motifs, not shared application plumbing. Each folder is a standalone micro-architecture built around one problem or one design pattern.

Main entry points: [`solutions`](https://github.com/ashishps1/awesome-low-level-design/tree/main/solutions) (Solutions), [`design-patterns`](https://github.com/ashishps1/awesome-low-level-design/tree/main/design-patterns) (Patterns), [`README.md`](https://github.com/ashishps1/awesome-low-level-design/blob/main/README.md) (README), [`solutions/java`](https://github.com/ashishps1/awesome-low-level-design/tree/main/solutions/java) (Java)

## Diagram (Mermaid)

```mermaid
flowchart TD

subgraph group_repo["Repo"]
  node_root["LLD Repo<br/>monorepo"]
end

subgraph group_docs["Docs"]
  node_readme["README<br/>guide<br/>[README.md]"]
  node_problems["Problems<br/>problem specs"]
end

subgraph group_oop["OOP"]
  node_oop_fundamentals["OOP<br/>fundamentals"]
end

subgraph group_patterns["Patterns"]
  node_pattern_root["Patterns<br/>pattern catalog"]
  node_creational["Creational<br/>pattern family"]
  node_structural["Structural<br/>pattern family"]
  node_behavioral["Behavioral<br/>pattern family"]
end

subgraph group_solutions["Solutions"]
  node_solutions_root["Solutions<br/>implementation catalog"]
  node_java["Java<br/>solution tree"]
  node_csharp["C#<br/>solution tree"]
  node_golang["Go<br/>solution tree"]
  node_python["Python<br/>solution tree"]
  node_typescript["TypeScript<br/>solution tree"]
  node_java_systems["Java systems<br/>domain examples"]
  node_csharp_systems["C# systems<br/>domain examples"]
  node_golang_systems["Go systems<br/>domain examples"]
  node_python_systems["Python systems<br/>domain examples"]
  node_ts_systems["TS systems<br/>domain examples"]
end

node_root -->|"documents"| node_readme
node_root -->|"contains"| node_oop_fundamentals
node_root -->|"contains"| node_pattern_root
node_root -->|"contains"| node_problems
node_root -->|"contains"| node_solutions_root
node_pattern_root -->|"families"| node_creational
node_pattern_root -->|"families"| node_structural
node_pattern_root -->|"families"| node_behavioral
node_solutions_root -->|"language"| node_java
node_solutions_root -->|"language"| node_csharp
node_solutions_root -->|"language"| node_golang
node_solutions_root -->|"language"| node_python
node_solutions_root -->|"language"| node_typescript
node_java -->|"organizes"| node_java_systems
node_csharp -->|"organizes"| node_csharp_systems
node_golang -->|"organizes"| node_golang_systems
node_python -->|"organizes"| node_python_systems
node_typescript -->|"organizes"| node_ts_systems
node_readme -.->|"points to"| node_solutions_root
node_readme -.->|"points to"| node_pattern_root
node_readme -.->|"points to"| node_oop_fundamentals

click node_readme "https://github.com/ashishps1/awesome-low-level-design/blob/main/README.md"
click node_problems "https://github.com/ashishps1/awesome-low-level-design/tree/main/problems"
click node_oop_fundamentals "https://github.com/ashishps1/awesome-low-level-design/tree/main/oop"
click node_pattern_root "https://github.com/ashishps1/awesome-low-level-design/tree/main/design-patterns"
click node_creational "https://github.com/ashishps1/awesome-low-level-design/tree/main/design-patterns/java"
click node_structural "https://github.com/ashishps1/awesome-low-level-design/tree/main/design-patterns/java"
click node_behavioral "https://github.com/ashishps1/awesome-low-level-design/tree/main/design-patterns/java"
click node_solutions_root "https://github.com/ashishps1/awesome-low-level-design/tree/main/solutions"
click node_java "https://github.com/ashishps1/awesome-low-level-design/tree/main/solutions/java"
click node_csharp "https://github.com/ashishps1/awesome-low-level-design/tree/main/solutions/csharp"
click node_golang "https://github.com/ashishps1/awesome-low-level-design/tree/main/solutions/golang"
click node_python "https://github.com/ashishps1/awesome-low-level-design/tree/main/solutions/python"
click node_typescript "https://github.com/ashishps1/awesome-low-level-design/tree/main/solutions/typescript"
click node_java_systems "https://github.com/ashishps1/awesome-low-level-design/tree/main/solutions/java/src"
click node_csharp_systems "https://github.com/ashishps1/awesome-low-level-design/tree/main/solutions/csharp"
click node_golang_systems "https://github.com/ashishps1/awesome-low-level-design/tree/main/solutions/golang"
click node_python_systems "https://github.com/ashishps1/awesome-low-level-design/tree/main/solutions/python"
click node_ts_systems "https://github.com/ashishps1/awesome-low-level-design/tree/main/solutions/typescript/src"

classDef toneNeutral fill:#f8fafc,stroke:#334155,stroke-width:1.5px,color:#0f172a
classDef toneBlue fill:#dbeafe,stroke:#2563eb,stroke-width:1.5px,color:#172554
classDef toneAmber fill:#fef3c7,stroke:#d97706,stroke-width:1.5px,color:#78350f
classDef toneMint fill:#dcfce7,stroke:#16a34a,stroke-width:1.5px,color:#14532d
classDef toneRose fill:#ffe4e6,stroke:#e11d48,stroke-width:1.5px,color:#881337
classDef toneIndigo fill:#e0e7ff,stroke:#4f46e5,stroke-width:1.5px,color:#312e81
classDef toneTeal fill:#ccfbf1,stroke:#0f766e,stroke-width:1.5px,color:#134e4a
class node_root toneBlue
class node_readme,node_problems toneAmber
class node_oop_fundamentals toneMint
class node_pattern_root,node_creational,node_structural,node_behavioral toneRose
class node_solutions_root,node_java,node_csharp,node_golang,node_python,node_typescript,node_java_systems,node_csharp_systems,node_golang_systems,node_python_systems,node_ts_systems toneIndigo
```

## Components

### Repo

Top-level educational monorepo boundary

- **LLD Repo**: monorepo · Educational low-level design catalog with docs, patterns, and solutions

### Docs

Learning path and problem statements

- [README](https://github.com/ashishps1/awesome-low-level-design/blob/main/README.md): guide · Learning path and repository overview · `README.md`
- [Problems](https://github.com/ashishps1/awesome-low-level-design/tree/main/problems): problem specs · Interview-style system prompts and requirements · `problems`

### OOP

Object-modeling fundamentals

- [OOP](https://github.com/ashishps1/awesome-low-level-design/tree/main/oop): fundamentals · Class relationship and design principle examples · `oop`

### Patterns

Pattern demos grouped by family

- [Patterns](https://github.com/ashishps1/awesome-low-level-design/tree/main/design-patterns): pattern catalog · Design-pattern demonstrations organized by family · `design-patterns`
- [Creational](https://github.com/ashishps1/awesome-low-level-design/tree/main/design-patterns/java): pattern family · Object creation examples and factories · `design-patterns/java`
- [Structural](https://github.com/ashishps1/awesome-low-level-design/tree/main/design-patterns/java): pattern family · Composition and wrapper examples · `design-patterns/java`
- [Behavioral](https://github.com/ashishps1/awesome-low-level-design/tree/main/design-patterns/java): pattern family · Interaction, state, and workflow examples · `design-patterns/java`

### Solutions

Standalone problem implementations by language

- [Solutions](https://github.com/ashishps1/awesome-low-level-design/tree/main/solutions): implementation catalog · Problem solutions organized by language with isolated trees · `solutions`
- [Java](https://github.com/ashishps1/awesome-low-level-design/tree/main/solutions/java): solution tree · Java implementations and Maven-based demos · `solutions/java`
- [C#](https://github.com/ashishps1/awesome-low-level-design/tree/main/solutions/csharp): solution tree · C# implementations and .NET projects · `solutions/csharp`
- [Go](https://github.com/ashishps1/awesome-low-level-design/tree/main/solutions/golang): solution tree · Go module-based implementations · `solutions/golang`
- [Python](https://github.com/ashishps1/awesome-low-level-design/tree/main/solutions/python): solution tree · Python module implementations · `solutions/python`
- [TypeScript](https://github.com/ashishps1/awesome-low-level-design/tree/main/solutions/typescript): solution tree · TypeScript/NPM implementations · `solutions/typescript`
- [Java systems](https://github.com/ashishps1/awesome-low-level-design/tree/main/solutions/java/src): domain examples · Stateful apps and service-style examples with observers, strategies, and states · `solutions/java/src`
- [C# systems](https://github.com/ashishps1/awesome-low-level-design/tree/main/solutions/csharp): domain examples · Rich problem solutions with layered model/service/state structures · `solutions/csharp`
- [Go systems](https://github.com/ashishps1/awesome-low-level-design/tree/main/solutions/golang): domain examples · Compact service and workflow examples per problem · `solutions/golang`
- [Python systems](https://github.com/ashishps1/awesome-low-level-design/tree/main/solutions/python): domain examples · Parallel solutions with the same educational motifs · `solutions/python`
- [TS systems](https://github.com/ashishps1/awesome-low-level-design/tree/main/solutions/typescript/src): domain examples · Lean demo implementations and supporting types · `solutions/typescript/src`

## Connections

- LLD Repo → README: documents · Repository overview and learning path
- LLD Repo → OOP: contains · Foundational OOP material
- LLD Repo → Patterns: contains · Pattern examples hub
- LLD Repo → Problems: contains · System prompts and specifications
- LLD Repo → Solutions: contains · Reference implementations catalog
- Patterns → Creational: families · Creation-focused examples
- Patterns → Structural: families · Composition-focused examples
- Patterns → Behavioral: families · Interaction and workflow examples
- Solutions → Java: language · Java solution tree
- Solutions → C#: language · C# solution tree
- Solutions → Go: language · Go solution tree
- Solutions → Python: language · Python solution tree
- Solutions → TypeScript: language · TypeScript solution tree
- Java → Java systems: organizes · Domain systems, states, strategies, observers, and demos
- C# → C# systems: organizes · Problem-specific micro-architectures and patterns
- Go → Go systems: organizes · Standalone example systems and demos
- Python → Python systems: organizes · Standalone example systems and demos
- TypeScript → TS systems: organizes · Compact demo-oriented implementations
- README → Solutions: points to · Shows the implementation catalog
- README → Patterns: points to · Shows the pattern catalog
- README → OOP: points to · Shows OOP learning material