#14-Ar | Our First Real Module! The Identity Modeling Decision | BuildFlow

BuildFlow #14 | Our First Real Module! The Identity Modeling Decision In this episode, we move from architectural foundations into the first real module of BuildFlow — Identity. Before writing code, we make an important domain-modeling decision: Should one user belong to one tenant, or can a user belong to multiple tenants? We explore both models, when each one makes sense, and why the right answer should come from business requirements—not unnecessary complexity. Then we put that decision into practice by creating the Identity Domain and defining its boundaries using Modular Monolith and Clean Architecture principles. In this episode, we cover: 🏢 One Tenant per User vs. Many Tenants per User 🎯 Why the model follows the requirements ⚙️ Avoiding unnecessary over-engineering 🏗️ Creating the BuildFlow.Identity.Domain project 🔒 Enforcing strict module boundaries 🧩 Why Identity Domain references only the SharedKernel 🆔 Creating a Strongly-Typed TenantId ⚖️ readonly record struct vs. class 📁 Organizing the Domain by Aggregates 💼 How to explain architectural decisions in a technical interview The goal is not simply to write code, but to understand why the architecture looks the way it does. This is where BuildFlow starts becoming a real modular application. 🛠️ Technologies & Architecture ASP.NET Core 8 C# Modular Monolith Clean Architecture Domain-Driven Design (DDD) Strongly-Typed IDs Shared Kernel Aggregate-Based Organization _________________________________ 🌐 BuildFlow-V3 — Live Demo Register your own tenant and walk through the full document workflow: Draft → Under Review → Approved → Archived (Multi-tenant .NET 8 SaaS). Link: https://build-flow-v3-orpin.vercel.app 💻 BuildFlow-V3 — Source Code (.NET 8) Modular Monolith, Domain-Driven Design (DDD), CQRS, Multi-tenancy, Redis Caching, OpenTelemetry, along with 90 unit tests and full CI. GitHub Repository: https://github.com/luaay/BuildFlow-V3 Live API Swagger: https://github.com/luaay/BuildFlow-V3 📂 Step-by-Step Tutorial Repository The complete source code linked step-by-step with the YouTube video series. Link: https://github.com/luaay/BuildFlow-Tu... 🎥 Full Video Series: 🇸🇦 Arabic Series:    • BuildFlow Demo | Engineering Document Work...   🇬🇧 English Series:    • 🚀 BuildFlow Demo | Build a Real Engineerin...   ________________________________ If you find this episode useful, Like 👍, Share, and Subscribe to follow the next steps in building BuildFlow. #BuildFlow #ASPNetCore #CSharp #DDD #CleanArchitecture #ModularMonolith #SoftwareArchitecture #DomainDrivenDesign #DotNet #SoftwareEngineering