AsEnumerable vs ToList vs AsQueryable in EF Core: Where SQL Stops and C# Starts
All three decide where your query stops being SQL and starts being C#. AsEnumerable streams and stays deferred; ToList buffers and runs immediately; AsQueryable on a List buys you nothing. Learn where to put the hand-off, why the streaming promise needs AsNoTracking, and the AsQueryable trap that only breaks in your tests.
IEnumerable vs IQueryable in EF Core: Why the Wrong Type Loads Your Whole Table
The difference is not the interface - it is the type of the lambda. Queryable.Where takes an expression tree EF Core can translate to SQL; Enumerable.Where takes a delegate it cannot read. Learn why switching to IEnumerable before you filter makes EF Core load the whole table, why its translation guard cannot save you there, and the overload trap that does it behind your back.
Transactions in EF Core: What SaveChanges Already Does, and When to Take Over
EF Core wraps every SaveChanges call in a transaction, so a single save is already atomic. You need BeginTransaction only when the all-or-nothing unit spans more than one save. Learn the automatic savepoints, the MARS trap that silently disables them, why explicit transactions throw once you enable retries, and how to share one transaction across contexts.
The Conditional UPDATE: Safe Background Jobs Across Many ASP.NET Core Instances
EF Core's ExecuteUpdateAsync returns the number of rows it changed. Put your precondition in the WHERE clause and that number becomes a verdict - zero means someone beat you to it. Microsoft documents this as concurrency control you implement yourself. Here is the technique, the check-then-act race it kills, and how it lets many instances share one job table safely.
How to Make Your ASP.NET Core Web API Stateless: Redis, HybridCache and Shared Storage
Part two of the horizontal scale series. Move the state that must be shared out of the web process: a distributed cache instead of IMemoryCache, HybridCache with stampede protection, a Redis-backed output cache, and shared object storage - plus what it costs you and what you can safely leave local.
Why Your ASP.NET Core Web API Breaks When You Scale It Horizontally
A Web API is supposed to be stateless, but several ASP.NET Core defaults are not. Run two instances and the built-in rate limiter, output cache, and in-memory cache each keep their own copy per process - so a "100 per minute" limit becomes 100 per instance. Learn which defaults break and how to move that state to a distributed store.
Per-Operation Timeouts in .NET: Why HttpClient.Timeout Is Not Enough
HttpClient.Timeout is infrastructure-level - it applies the same budget to every call. Learn how to use CancellationTokenSource and CreateLinkedTokenSource to set per-operation timeouts that compose with the caller token and tell you exactly who cancelled.
Python Inheritance Explained: Simple, Chain, Hierarchical and Multiple
Python supports four types of inheritance. Learn how simple, chain, hierarchical, and multiple inheritance work with practical examples, how the MRO resolves method conflicts, and when to prefer composition over inheritance.
EF Core Under the Hood: 11 Design Patterns You Use Every Day
EF Core implements Unit of Work, Repository, Identity Map, Strategy, Builder, Factory, Object Pool, Interceptor, Template Method, Query Object, and Value Object. Understanding these patterns explains most of EF Core's behaviour - and most of its surprises.
Impedance Mismatch in Software: What It Is and Why It Matters
Impedance mismatch describes the friction between two systems built on fundamentally different models. Learn what it means, why the object-relational mismatch is the classic example, and where EF Core abstractions leak.
C# Records vs Classes: When to Use Each and Why
Records and classes look similar in C# but behave very differently. Learn how value equality, with expressions, and immutability make records the right choice for data models - and when to stick with classes.
SQL JOINs Explained: INNER, LEFT, RIGHT, FULL OUTER and SELF JOIN with Examples
A clear explanation of SQL INNER JOIN, LEFT JOIN, RIGHT JOIN, FULL OUTER JOIN and SELF JOIN with practical examples. Learn what each join returns and when to use it.
AZ-204 Is Retiring: What Azure Developers Need to Know About AI-200
Microsoft is retiring the AZ-204 Azure Developer Associate certification on July 31, 2026, replacing it with AI-200. As someone who holds AZ-204, here is everything I found out — what changes, what stays, and what you should do next.