@grainloom Recursively templated templates: first template uses second template, second template uses third template, and so on. They're also eagerly evaluated, so as soon as a template appears inside another template, it gets replaced *as part of the template*, rather than deferring the replacement to when the template is used. This can significantly reduce memory usage. Buttons? One template for them all. Posts? Just one. Columns? Same. All of mastodon, in 3 templates + very simple support JS to insert them.