WordPress.org
Get WordPress

Profiles

Christoph Daum

Senior Software Developer at Coding Pioneers

@apermo Germany, Bergkamen joined Nov 2011

christoph-daum.de github.com/apermo Slack: @Christoph Daum (apermo)
    Teams Community Core
    Languages de_DE

    Bio

    Christoph is a WordPress and PHP specialist, with over 25 years of experience in web development. He started first web projects in the late 90s, some of which are still leading in their field. As technical lead on multiple projects with millions page impressions per month, his responsibilities included theme and plugin development, performance optimizations, and feature planning.

    Christoph is a contributor to the WordPress ecosystem, host and founder of his local WordPress Meetup in Dortmund, and a frequent speaker at meetups and WordCamps.

    Interests

    WordPress, PHP, 3D Printing, DIY

    WordPress Origin Story

    I started of doing mostly TYPO3 when my good friend Hendrik Luehrsen @luehrsen talked in the highest tones about WordPress. Later during my agency days, I started working with WordPress, and in 2012 I attended my first WordCamp in Berlin, which was called WPCamp. On my second WordCamp in 2013, I met Robert Windisch @nullbyte, well and for everyone who knows Robert, this is all you need to know. Since that day, I’ve only missed a 3 WordCamps in Germany, I became founder and host of my local WordPress Meetup and I’m part of the “usual suspects” to buy a WordCamp ticket on release day.

    Since 2014 I call myself an in-house developer for WordPress, doing WordPress as a full-time job. During these days I’ve dug very deep into multiple areas of the WordPress code, found a few bugs, suggested some improvements and the best is yet to come.

    Badges

    CODE
    2 badges
    Core Contributor '19 Plugin Developer
    CONTENT
    1 badge
    Documentation Contributor '23
    COMMUNITY
    3 badges
    Meetup Organizer '18 WordCamp Speaker '16 WordCamp Volunteer '26
    POLYGLOTS
    2 badges
    Translation Contributor '16 Translation Editor '16

    Current Job

    Senior Software Developer
    Present
    Coding Pioneers

    Recent impact

    Score weights high-impact work (commits, releases, approved translations, props) at 3x routine activity.

    Last 30 days
    9contributions
    high8
    medium1
    score25
    Last 90 days
    22contributions
    high19
    medium3
    score60
    Last 12 months
    93contributions
    high64
    medium29
    score221

    Team focus

    Share of contributions across teams during the last 365 days

    WordPress releases

    Contributed to 11 releases
    • 7.0
    • 6.9
    • 6.8
    • 6.7
    • 6.6
    • 6.3
    • 6.2
    • 6.1
    • 5.6
    • 5.4
    • 5.3

    Time commitment

    4 hours per week of sponsored contribution time

    Contributions

    Type
    July 2026
    Jul 21 Tue · 23:17
    Core high
    Mentioned in [62815] on WordPress SVN:
    REST API: Normalize non-integer attachment `filesize` metadata.
    Jul 21 Tue · 22:46
    Core high
    Mentioned in [62813] on WordPress SVN:
    Code Quality: Ensure `wp_filesize()` always returns a `non-negative-int`.
    Jul 20 Mon · 11:34
    Core med
    Submitted pull request #12611 to WordPress/wordpress-develop:
    REST API: Normalize non-integer attachment filesize metadata
    Jul 20 Mon · 11:32
    Core med
    Created ticket #65670 on Core Trac:
    WP_REST_Attachments_Controller::get_attachment_filesize() fatals on ...
    Jul 15 Wed · 09:03
    Core high
    Mentioned in [62754] on WordPress SVN:
    Posts, Post Types: Style password form button in block themes.
    Jul 09 Thu · 19:34
    Core high
    Mentioned in [62681] on WordPress SVN:
    Widgets: Add "On This Day" dashboard widget.
    Jul 07 Tue · 08:25
    Core high
    Mentioned in [62653] on WordPress SVN:
    Docs: Update since tag for `wp_get_user_request()`.
    Jul 01 Wed · 21:32
    Core high
    Mentioned in [62619] on WordPress SVN:
    REST API: Add dimension validation to sideload endpoint.
    June 2026
    Jun 28 Sun · 20:38
    Core high
    Mentioned in [62567] on WordPress SVN:
    Administration: Fix selected/active buttons in High Contrast Mode.
    Jun 25 Thu · 09:08
    Core high
    Mentioned in [62557] on WordPress SVN:
    Allow customization of the AI Client object cache group

    Developer

    4 plugins

    Contributor

    1 plugin

    Completed courses

    1 completed

    Browse courses on Learn WordPress

    Plugins

    7 favorites

    Translations

    2 locales
    de_DE Deutsch (German) Patterns Translation Editor Project Translation Editor Translation Contributor

    Translation editor for 1 project.

    Patterns

    Translation editor for 2 projects.

    Plugins Themes

    Contributed translations to 5 projects.

    Apermo AdminBar Apermo AdminBar Toggle Apermo Xdebug Ninja Forms – The Contact Form Builder That Grows With You Yoast SEO – Advanced SEO with real-time guidance and built-in AI

    View all on translate.wordpress.org

    de_DE / formal Deutsch (German) Translation Contributor

    Contributed translations to 2 projects.

    Apermo AdminBar Apermo Xdebug

    View all on translate.wordpress.org