Writing Clean Code for API Development

.NET 10 Clean Architecture + Vertical Slice Template I've built and open-sourced a modern .NET 10 REST API template designed with Clean Architecture + Vertical Slice Architecture + CQRS structured the way scalable, maintainable systems should be built. It can easily save you 100+ hours of setup, refactoring, and architectural cleanup. 𝗪𝗵𝘆 𝗧𝗵𝗶𝘀 𝗧𝗲𝗺𝗽𝗹𝗮𝘁𝗲? Most templates stop at CRUD. This one focuses on real-world architecture. - Clean Architecture (Domain → Application → Infrastructure → WebApi) - Vertical Slice Architecture (feature-first structure inside Application) - Clean CQRS separation (Commands & Queries) - Minimal APIs for high performance - FluentValidation pipeline (automatic validation) - Logging decorators (request/response tracing) - Audit Interceptor (automatic CreatedOn/UpdatedOn tracking) - Global exception handling - Result<T> pattern for consistent error responses - Health checks (DB readiness & liveness) - PostgreSQL + EF Core 10 - Scalar UI (modern OpenAPI experience) 𝗛𝗼𝘄 𝗜𝘁'𝘀 𝗦𝘁𝗿𝘂𝗰𝘁𝘂𝗿𝗲𝗱 4 clean projects with strict inward dependency: 📁 Domain - Entities, Result<T>, Error types (zero dependencies) 📁 Application - Vertical slices (Handler + Validator + Endpoint per feature), Pipelines, Abstractions 📁 Infrastructure - EF Core, Repository, UnitOfWork, Audit Interceptor 📁 WebApi - Thin host (Program.cs, Exception Handler, Health Checks) 𝗪𝗮𝗻𝘁 𝘁𝗵𝗶𝘀 𝗽𝗿𝗼𝗱𝘂𝗰𝘁𝗶𝗼𝗻-𝗿𝗲𝗮𝗱𝘆 .𝗡𝗘𝗧 𝘁𝗲𝗺𝗽𝗹𝗮𝘁𝗲? 👉 The GitHub repository link is available in the comments 👉 If you find it useful, please star ⭐ the repo 👉 Share this post with your network 🙌 After you try it, message me your thoughts I actively improve it based on real-world feedback. 💾 Save this for later & repost if this helped 👤 Follow Kanaiya Katarmal + turn on notifications.

If I were just starting out with APIs, these are the 10 rules I’d follow. These best practices will help you create simple, clear, and consistent APIs that are easy to use and understand. 1/ Keep It Simple   ↳ Use clear, concise endpoints that describe resources.   ↳ Avoid over-complicating; keep naming consistent and understandable.   ↳ Example: `/books` for all books, `/books/{id}` for a specific book. 2/ Use RESTful Design   ↳ Use standard HTTP methods: GET, POST, PUT, DELETE.   ↳ Name endpoints with nouns like `/users` or `/orders` for clarity.   ↳ Example: HTTP code 200 (success), 404 (not found), 500 (server error). 3/ Choose Standard Data Formats   ↳ Use JSON as it’s readable and widely supported.   ↳ Keep data formats consistent across endpoints.   ↳ Example: `{ "title": "To Kill a Mockingbird", "author": "Harper Lee" }`. 4/ Provide Clear Documentation   ↳ Document endpoints with detailed descriptions.   ↳ Provide request and response examples for easy usage.   ↳ Example: Explain `/users/{id}` with request/response samples. 5/ Implement Versioning   ↳ Include versioning in the URL to manage changes.   ↳ Allow for updates without breaking existing clients.   ↳ Example: `/v1/books` for version 1, `/v2/books` for an updated version. 6/ Ensure Security   ↳ Use HTTPS for data encryption.   ↳ Implement authentication and authorization mechanisms.   ↳ Example: OAuth 2.0 to secure user access to APIs. 7/ Handle Errors Gracefully   ↳ Use standard HTTP status codes like 400, 404, and 500.   ↳ Provide informative error messages to help resolve issues.   ↳ Example: `400 Bad Request` for invalid input, with a detailed error message. 8/ Optimize Performance   ↳ Use caching to store frequent responses and speed up access.   ↳ Apply rate limiting to control the number of requests a user can make.   ↳ Example: Cache popular books, limit requests to prevent server overload. 9/ Test Thoroughly   ↳ Conduct functionality, performance, and security testing.   ↳ Ensure different user scenarios are tested for reliability.   ↳ Example: Use automated tools for end-to-end testing before deployment. 10/ Monitor and Update   ↳ Monitor API performance and user activity continuously.   ↳ Update the API to address bugs or add features regularly.   ↳ Example: Use Prometheus to monitor latency and health. – P.S: What would you add from your experience?

🚀 Java (Spring Boot) – Clean Project Structure Matters! Over the years of working with Spring Boot and microservices, one lesson stands out: 🧱 A clean, well-structured project is not just nice-to-have — it’s essential. Without structure, things get messy fast. Bugs multiply, onboarding becomes painful, and scaling becomes a nightmare. Here’s what I always keep in mind: 🧠 Best Practices for Clean Architecture: ✅ Use DTOs to isolate your API layer from business logic ✅ Never connect directly to another service’s database — use REST APIs or message brokers ✅ Keep services small, modular, and single-responsibility ✅ Use Spring Cloud Config or Vault to manage configuration ✅ Document your APIs with Swagger, Postman, or OpenAPI ✅ Always write integration + unit tests to ensure system reliability 🧰 Clean structure = maintainable code 📈 Maintainable code = faster delivery and easier growth What are your go-to practices for organizing a Spring Boot project? Let’s share and grow together. 💬👇 #SpringBoot #JavaDeveloper #Microservices #SoftwareArchitecture #CleanCode #BackendDevelopment #SpringFramework #API #JavaTips #DevBestPractices #CodingStandards #TechLeadership #AkashCodes #CleanArchitecture

Clean Architecture in .NET – Scalable & Maintainable Project Structure Over the past few months, I’ve been architecting enterprise-grade applications using Clean Architecture principles in .NET — and the impact has been incredible! 💥 ✅ Scalability improved ✅ Code became modular & testable ✅ Development speed increased Here's the structure I follow to keep things clean, decoupled, and easy to maintain: 📂 API / Presentation Layer 🎯 Entry point for HTTP requests via Controllers 🧭 Sends Commands/Queries to the Application layer 🧩 Configures Dependency Injection in Program.cs / Startup.cs 📂 Application Layer ⚙️ Pure Application Logic – no infrastructure dependencies 📬 Implements CQRS using MediatR 🔁 Handles DTOs, Mapping, Events & Custom Exceptions 📂 Domain / Core Layer 🏛️ Contains core business rules and domain models 💼 Includes Entities, Interfaces, Domain Services 🚫 No EF Core, No HTTP, No UI logic 📂 Infrastructure Layer 🗄️ Handles persistence, file system, email, external APIs 🧱 Implements interfaces defined in the Domain Layer 🔌 Injected into the Application layer via DI 🎯 Why it works: This structure enables clean, scalable, and testable applications – perfect for microservices and enterprise systems. #DotNetCore #CleanArchitecture #Microservices #ScalableCode #SoftwareEngineering #CSharp #CodeStructure #DevArchitecture #DomainDrivenDesign #MediatR #CQRS #FullStackDeveloper #MaintainableCode #EnterpriseApps #CleanCode #SOLIDPrinciples

💡 𝐇𝐨𝐰 𝐈 𝐒𝐭𝐫𝐮𝐜𝐭𝐮𝐫𝐞 𝐌𝐲 𝐌𝐢𝐧𝐢𝐦𝐚𝐥 𝐀𝐏𝐈𝐬 – 𝐅𝐨𝐥𝐝𝐞𝐫 𝐛𝐲 𝐅𝐨𝐥𝐝𝐞𝐫 Minimal APIs look simple, but clean structure is key to scale and maintainability. Here’s how I break it down: 📁 Notes.Api ├── 📁 Contracts ├── 📁 Database ├── 📁 Domain ├── 📁 Endpoints │ └──📁 Notes │ ├── CreateNoteEndpoint.cs │ ├── DeleteNoteEndpoint.cs │ └── GetAllNotesEndpoint.cs │ └── NoteEndpoints.cs // (optional) just NotesEndpoints.cs ├── 📁 Mapping ├── 📁 Migrations ├── 📁 Services └── 📁 Validation └── CreateNoteRequestValidator.cs A good structure brings clarity. It helps developers understand the flow, reduces bugs, and makes future improvements easier to implement. I usually organize by feature using REPR pattern, adding validators and mappings as needed. But for smaller projects, I keep it simple, just organize by endpoints and group logic in a single file. 📌 Bonus: Keep Program.cs with a few lines. If it’s growing too much, extract. Modularize. 💬 How do you organize your Minimal APIs? ❤️ Like if clean structure matters! 🔄 Share to help others build scalable projects! #MinimalAPI #DotNet #CSharp #BackendTips #CleanCode #DevProductivity #SoftwareArchitecture #WebAPI #Microservices #DotNetDev #CleanArchitecture