est. 2005 · back in action

Learn to build real software, step by step.

coder000 is a friendly corner of the internet where you learn to code step by step, with no jargon and no gatekeeping. Three paths run through it: learn the stack, build a real app with AI, and prepare for your next interview.

Learn the stack See everything

Three paths, and two shortcuts

All series →

Each path is a set of complete series in a sensible order. Fixes and Tools are for the day something breaks.

Fundamentals, in order

Learn the stack

The Windows PC, Docker, Git, Blazor, PostgreSQL and database design, each as a complete series that assumes nothing and ends with you capable.

Set Up a Windows PC for .NET Development 6 parts
Docker for .NET Developers on Windows 8 parts
Git & GitHub: Zero to Advanced 10 parts
Blazor: Beginner to Intermediate 12 parts
SQL Server → PostgreSQL 8 parts
Conversation to System Design 7 parts
Database Design for Developers 12 parts

Plus standalone posts in Web & APIs, C# & .NET, Databases & Data and Developer Craft.

Start here Everything in this path

One real app, four seasons

Build with AI

ClinicLive, a clinic app built with an AI pair programmer from the first prompt to a private on-premises assistant, every prompt shown and every mistake kept.

Plus standalone posts in AI & Modern Coding.

Start here Everything in this path

Questions and worked answers

Prepare for interviews

Two series that take a .NET developer and an AI engineer through the questions they will actually be asked, with worked answers.

The .NET Developer Interview 9 parts
The AI Engineer Interview 7 parts

Start here Everything in this path

Error messages, decoded

Fixes

105 posts, each titled with the exact error text you searched for. The newest:

Paste an error All 105 fixes

Free, no signup

Tools

14 rule-based tools that explain their answer, not just give it. Four to try:

New on the site

All posts →

Databases & Data

PostgreSQL 16 vs 18 for .NET Developers: Run Side by Side

PostgreSQL 16 vs 18, run side by side. uuidv7, virtual generated columns, RETURNING OLD and NEW, temporal keys, skip scans, and how to move a dev database. Oct 14, 2026 6 min read

AI & Modern Coding

Install Ollama on Linux and WSL: What the One-Liner Really Does

Install Ollama on Linux and WSL, run on a bare Ubuntu 24.04. Why it needs zstd, what it creates with or without systemd, where models live, the manual route. Oct 14, 2026 6 min read

Databases & Data

The dotnet ef Commands, Run and Explained: migrations, database and dbcontext

Every dotnet ef command run on a real solution. Target and startup project, add, list, script, remove, database update, dbcontext optimize and scaffold. Oct 14, 2026 6 min read

Kestrel Ports and URLs: launchSettings, --urls, ASPNETCORE_URLS, appsettings and UseUrls

Which port an ASP.NET Core app listens on, and why. launchSettings, --urls, ASPNETCORE_URLS, appsettings Kestrel endpoints and UseUrls, run against each other. Oct 14, 2026 6 min read

Developer Craft

WSL Users and Passwords: The Default User, Root, and a Forgotten sudo Password

How WSL picks the user you log in as, and how to change it. Reset a forgotten sudo password from Windows, root's password, wsl.conf and --set-default-user. Oct 14, 2026 6 min read

AI & Modern Coding

Ollama Ports, OLLAMA_HOST and 11434, Explained on a Real Machine

Why Ollama listens on 11434 and how to change it. OLLAMA_HOST on client and server, binding to the network, OLLAMA_ORIGINS for browsers, Windows next to WSL. Oct 14, 2026 6 min read

Start here, by reader

Not sure which path is yours? Three first reads for three kinds of reader.

If you are

A student

Why Version Control Exists: A Short History of GitPart 1 of Git & GitHub: Zero to Advanced
From ER diagram to CREATE TABLEPart 1 of Database Design for Developers
Hello, Blazor: Set Up and Build Your First AppPart 1 of Blazor: Beginner to Intermediate

If you are

A working .NET developer

SQL Server to PostgreSQL: Why Switch, and What to ExpectPart 1 of SQL Server → PostgreSQL
Fixeserror messages, decoded
DDL to EF Core entitiesfree tool

If you are

Building with AI

AI-Assisted Development in 2026, HonestlyPart 1 of From Prompt to Production
What a Real App Built with AI Actually Costthree seasons, every meter reading
A Clinic's Own AI, on Its Own ServerPart 1 of From Prompt to Private