COURSES + FIELD NOTES 12 courses · 8 disciplines EST. 2024

From a first script to a service in production.

WPSifero publishes courses and technical writing about programming. Five language courses — Python, JavaScript and TypeScript, PHP, SQL and Go — run from your first program to the parts you only meet under real traffic. Five more go deep into WordPress and WooCommerce, because that is where the two hardest things in this trade meet: a codebase you did not write, and a database under load.

Every course is text. No video, nothing to scrub through, nothing to re-watch at half speed. You read a lesson, type the code yourself, and finish with something that runs.

Browse the courses Read the articles

Curriculum status

$ wpsifero --curriculum

[ OK ]Go 1.24+18/18

[ OK ]Node 22 LTS+18/18

[ OK ]PHP 8.3+18/18

[ OK ]Python 3.12+18/18

[ OK ]MySQL · PostgreSQL · SQLite18/18

[ OK ]WordPress 7.0 · WooCommerce 11.218/18

[ OK ]WooCommerce 11.218/18

[ OK ]WordPress 7.018/18

[ OK ]WordPress 7.0 · PHP 8.5 · Claude Code · Codex · OpenCode18/18

[ OK ]WordPress 7.0 · Redis18/18

[ OK ]WordPress 7.018/18

[ OK ]WordPress 7.0 · PHP 8.3+18/18

$ _

Courses: 12
Lessons: 216
Articles: 124
Reading time: 137H 07M

01 Sector map

What you will find here

Three shelves: the languages, the platform, and the disciplines that apply to all of it.

LANG

The languages

Five courses, each running from your first program to the parts that only show up in production. Text, with a lab and a worked solution in every lesson.

Open the language courses

WP

WordPress and WooCommerce

The platform that runs a large share of the web, written against WordPress 7.0 and WooCommerce 11.2 rather than against tutorials from three versions ago.

Open the WordPress courses

DISC

The disciplines

The subjects that do not care which language you write: query budgets, cache invalidation, REST contracts, capability checks, accessibility, tooling.

Browse the articles

01 Lead transmission

This month's deep dive

Long-form work where the measurement matters more than the opinion.

Topic: WOO
Section: WooCommerce & Storefront
Published: 06 OCT 2026
Reading time: 7 MIN
Words: 1977W

Building Order Tracking in WooCommerce Without a Tracking Subscription

Most post-purchase support tickets are "where is my order". Here is the plugin architecture that answers them without shipping customer data to a tracking service.

Ana Ferreiro · @aferreiro

WooCommerce engineering

Covers the WooCommerce order lifecycle: checkout, HPOS, session handling, transactional email and the post-purchase layer where most storefront complaints actually originate.

Read the full analysis

02 Curriculum

Courses you read, not watch

12 complete text courses, 216 lessons, no video. Written to be read at your own pace and typed out rather than copied.

DEV05 COURSES

Programming track

Language and platform courses that start at a first script and end at the parts you only meet in production.

Go for Backend Services18 lessons · 10H 30M
JavaScript and TypeScript, from Script to Application18 lessons · 10H 15M
Modern PHP, from Syntax to Services18 lessons · 9H 21M
Python from First Script to Service18 lessons · 9H 25M
SQL and Relational Database Design18 lessons · 11H 10M

WP07 COURSES

WordPress track

Courses built against WordPress 7.0 and WooCommerce 11.2, covering plugin and block development through to performance and security.

Building the Sifero Courier Timeline Plugin18 lessons · 8H 50M
WooCommerce Extension Development18 lessons · 10H 35M
WordPress Block Themes and Full Site Editing18 lessons · 10H 00M
WordPress Development with AI Agents18 lessons · 10H 15M
WordPress Performance and Scaling18 lessons · 10H 25M
WordPress Plugin Development18 lessons · 8H 45M
WordPress Security and Hardening18 lessons · 10H 45M

Open the course catalogue How this material is written

02 Transmission log

Latest articles

Newest first. Every entry is tagged by discipline and carries an estimated reading time.

001 Disaster Recovery for WordPress: RTO, RPO and a Runbook Backups are an ingredient, not a plan. How to set recovery targets, choose a standby strategy and write a runbook someone can follow at 2am. INFRA Devon Parker 20 OCT 2026 · 8M 002 What WordPress.org Reviews Before It Lists a Plugin A place in the plugin directory is a review result, not a security guarantee. What the volunteers check, what they do not, and how to read the signals. WP Martin Kiel 20 OCT 2026 · 8M 003 What a Restorable WordPress Backup Actually Contains A tar of wp-content and a database dump can still restore into a broken site. The parts a complete backup needs, and the ones people leave out. WP Martin Kiel 20 OCT 2026 · 7M 004 The Week After a WordPress Migration Decides If It Worked DNS cutover is the midpoint. What to verify in the first seven days, from redirects and cron to the email nobody tested and the host you must not cancel yet. WP Martin Kiel 20 OCT 2026 · 7M 005 Self-Hosted WordPress: the Maintenance You Are Taking On The hosting bill is the visible cost of self-hosting. The recurring work is the rest of it, and what that work is each month. INFRA Martin Kiel 20 OCT 2026 · 8M 006 Restore to Staging First, Then Decide About Production A restore overwrites the only site you have. Why the safe order is staging first, what it catches, and when a direct restore is the right call. WP Martin Kiel 20 OCT 2026 · 7M 007 A Restore Drill You Can Run in Thirty Minutes a Month A backup proves nothing until it is restored under a clock. The monthly drill that measures how long recovery takes and what breaks quietly. INFRA Tomas Lindqvist 20 OCT 2026 · 8M 008 When the Host Disappears: Recovering a Site You Lost Suspension, takeover and provider collapse leave you without the panel. What to secure first, what to rebuild, and what to do when the data is gone. INFRA Tomas Lindqvist 20 OCT 2026 · 8M 009 Preserving Search Rankings Through a WordPress Migration Search traffic follows URLs, not servers. The redirect map, canonical and sitemap work that keeps a migration from erasing years of rankings. WP Martin Kiel 20 OCT 2026 · 8M

Open the complete index (124 articles)

04 Sector map

Topics

Eight disciplines, each with its own archive and its own set of recurring failure modes.

WP35

WordPress Internals

Hooks, the database layer, cron, and the parts of core that decide how your plugin behaves under load.

WOO13

WooCommerce & Storefront

Order lifecycle, checkout, HPOS, sessions and the post-purchase communication layer.

PERF10

Performance

Query budgets, object caching, Core Web Vitals and measuring before you optimise.

API06

APIs & Integrations

REST design, webhooks, authentication, idempotency and talking to couriers and ERPs.

SEC13

Security & Hardening

Capability checks, nonces, sanitisation, SQL safety and threat modelling for plugins.

FE15

Frontend & Accessibility

Block themes, progressive enhancement, ARIA, and interfaces that work without JavaScript.

TOOL09

Tooling & Workflow

Local environments, static analysis, CI, release packaging and debugging technique.

INFRA23

Hosting & Infrastructure

Server configuration, caching layers, queues, observability and deployment practice.

05 Operating principle

What we publish, and what we refuse to

This section exists so readers and reviewers can hold us to a stated standard.

Every claim is reproducible

Performance numbers come from a stated environment. We publish the query count, the cache state and the sample size, because a benchmark without its conditions is an advertisement rather than a measurement.

Disagreement is documented

Where a recommended pattern has a cost, that cost appears in the same article rather than a follow-up. If an approach fails past a certain order volume, we say at which volume it fails.

No undisclosed interests

WPSifero maintains its own plugins. Whenever an article touches a product we build, the relationship is disclosed inside that article, at the top, in plain language.

Read the full editorial standards