18 articles.
Leader election and leases answer a comforting question: who should be in charge right now. They do not fully answer the dangerous question: who can still write right now. A node can lose its lease…
Indefinite locks belong to a world where processes never crash and networks never split. That world does not exist. In a distributed system, “I hold the lock” can mean…
If your service runs on more than one node and still has a single instance assumption, you already have leader election. You just do not have it on purpose. Leader…
Distributed systems rarely fail because you picked the wrong cloud service. They fail because two nodes believe they are in charge, both act, and both are “correct” from…
Distributed systems do not fail because you missed a feature. They fail because responsibility is unclear. Two nodes act, both think they are right, and your data…
Your domain model exists to protect your business rules. Your API exists to protect your clients. When you expose EF Core entities directly from your ASP.NET Core…
If every controller in your system does its own authentication, logging, and error handling, you do not have an architecture. You have a crowd of small frameworks…
If a single endpoint pulls half your database just to render a small card on a mobile screen, your problem is not the database. Your problem is that you are afraid to…
If one customer quietly turns into three different in-memory objects during a single request, your domain is already lying to you. You see it when: - Different parts of…
If a single business operation calls SaveChangesAsync three times, you do not have a transaction. You have a sequence of partial commits that you hope never fails in the…
If DbContext shows up in every corner of your codebase, you do not have a domain model. You have a thin layer of LINQ wrapped in HTTP. You see it when: - Minimal API…
If every interesting class in your system secretly knows a connection string, your domain is not a model. It is a thin layer of code on top of a data access layer. You…
Sometimes, your domain is really just rows in a table. You have a Customers table with Id, Email, and CreditLimit. You load a row, tweak a field, and write it back. That…
Open a typical ASP.NET Core project, and you will often see the same shape: - Controllers that validate input, construct entities and call several repositories - Direct…
Look at a typical enterprise ASP.NET Core application, and you often see the same pattern: - Controllers validating requests, calculating totals, and applying discounts…
Picture this. Product wants a minor discount tweak: if an order total is below 100, no discount. You open an endpoint, add a conditional, save and push. Ten minutes, job…
Most enterprise systems already use patterns from Martin Fowler’s Patterns of Enterprise Application Architecture. The twist is that many teams use them without naming…
Walk into almost any long-lived enterprise codebase, and you will find the same pattern: - Controllers that know about routing, JSON, SQL, and domain rules -…
