Once, the Drupal community had Mollom, and everything was good. It was a web service that would let you use an API to scan comments and other user-submitted content and it would let your site know whether it thought it was spam, or not, so it could safely publish the content. Or not. It was created by our very own Dries Buytaert and obviously had a Drupal module. It was the service of choice for Drupal sites struggling with comment spam. Unfortunately, Mollom no longer exists. But there is an alternative, from the WordPress world: Akismet.
When deploying changes to a Drupal environment, you should be running database updates (e.g. drush updb, or through update.php) first, and only then import new configuration (which itself is supposedly the result of running the same update hooks on a development environment). The reason for this is that update hooks may want to update configuration, which will fail if that configuration is already structured in the new format (you can't do without updates either; update hooks don't just deal with configuration, but may also need to change the database schema and do associated data...
At last month's DrupalJam XL in Utrecht, the Netherlands, I gave Gabor Hojtsy's presentation on the state of Drupal 9. It was recorded - thanks DrupalJam organization! - so here is the video. You might also want to view Gabor's own presentation from DrupalCamp Belarus.
You'll need to turn up the audio, because it seems that it was recorded using the camera, not the fancy microphone I'm wearing.
Drupal 8 will actively complain when your site does not have a hash_salt configured, which usually gets generated when installing the site. (The complaint, mind you, might be fairly obscure; your site might just say "The website encountered an unexpected error. Please try again later." Depending on your error reporting settings, the message might be a bit more helpful). If, for example, you "install" a site by copying over a database and files, you will not have this.
Last weekend, the DrupalCamp Ruhr was held in Essen, Germany. I was fortunate enough to have been selected as a speaker. I've now made the slides available online.
If you have the Media module for Drupal 8 installed (not a requirement to use media with Drupal 8, so this post may not apply to you), you need to remove it before you can upgrade to the latest core version (8.4). Unfortunately, there are a few gotchas involved with the process. This blog post is about getting rid of the old contrib Media module, so the site can be updated to Drupal 8.4 in a subsequent step. This is based on my personal experience. YMMV, as they say.
Another good one for the responsible coder. Code reviews are a tricky thing. They can improve software quality tremendously; two know more than one, obviously. However, it is all too easy to invoke bad feelings in the reviewee (if you think, "They should just grow thicker skin, it's not personal", this is especially for you).
Very thorough overview from Lullabot. Even though I think overall I am pretty good at this stuff, I picked up one or two tips, like writing ticket titles to complete the phrase “This ticket will….” (writing ticket titles and commit message starting with a verb is nothing new, but this is a helpful little mind trick).
Just now I was looking for how to type an emdash on the Mac (and also, whether my intended use was actually correct). I found this great little article.