- Template maintenance: created or significantly contributed to most major Commons infobox templates used in file namespace. Created current versions of Creator and Institution templates and namespaces.
- Rewriting templates in Lua: rewrote many infoboxes templates in Lua including: Artwork, Art photo, Photograph, Creator, Institution, Information (not live yet), Authority control and Location. All of them can draw now data from Wikidata. Rewrote many high-use low level internationalization templates like ISOdate, Date, Other date, orCity templates.
- Maintaining of multiproject Lua modules: Module:DateI18n (Q56528363), Module:ISOdate (Q26209111), Module:Complex date (Q26905045), Module:Calendar (Q59263842), Module:LangSwitch (Q58832772), Module:Autotranslate (Q59264012), Module:Wikidata label (Q22050722), Module:Wikidata date (Q31202303)
- Moving metadata from Commons to Wikidata. In April 2016, Commons got access to Wikidata, so now our templates can access Wikidata properties. Wikidata is much better place for storing matadata related to people, places or significant objects or artworks, so we are in process of reconciling and moving some of it from Commons to Wikidata.
- Help develop data model for copyright statements on Wikidata, and added copyright statements to few hundred thousands items
- Administer Commons Photo Challenge
- Volunteer at OTRS and occasionally help with permissions-commons queue
- Run User:JarektBot, doing over 3.7M edits since 2008
- Photography:Take and upload my own photographs, see Category:Photographs by Jarek Tuszynski