[bjourne]

Blog posts are prima-facie evidence of notability. Same thing with mentions in published articles. From the book (second link):

"Recognizing that Value Vectors meet the needs of other data processing engines, in February 2016, the Apache Software Foundation announced Apache Arrow as a top-level project, bypassing the standard Incubator process. Committers to the project include developers from other Apache projects such as Calcite, Cassandra, Drill, Hadoop, HBase, Ibis, Impala, Kudu, Pandas, Parquet, Phoenix, Spark and Storm.

Apache Arrow enables execution engines like Spark to take advantage of the latest operations included in modern processors, for fast analytical data processing. Columnar layout of data allows for better use of CPU caches by placing all data relevant to a column operation in as compact of a format as possible. ...

Apache Arrow software is available under the Apache License v2.0.

Dremio, a startup led by Jacques Nadeau, chair of the Apache Drill and Apache Arrow Project Management Committees, leads the development."

In the past, this and the other sources would have been more than enough to establish notability. I know that because I have created Wikipedia articles on subjects much less notable than that. The problem for Apache Arrow isn't that it isn't notable enough, it is that people have already tried four times to get it included in Wikipedia so the Wikipedians voting on new page inclusions are getting suspicious about it.

[tptacek]

If you want to sum up something like 10 years of debate and consideration of the role of blogs as sources (it’s much more complicated than that they’re not allowed) by saying, in effect, “you’re all wrong”, well you do you.

[bjourne]

I'm merely saying that you are wrong. Blogs are not always reliable sources in the Wikipedia world, but they can absolutely be used as evidence for notability.

[tptacek]

Not routinely, and not most blogs. As you can clearly see from the admin comments on this Arrow post.

[bjourne]

Yes, routinely. You can find plenty of articles which had much less support in sources when they were created here https://en.wikipedia.org/wiki/Category:AfC_submissions_by_da... That Wikipedians rejected the article is a moot point because the argument is that the rules are not applied consistently.

[tptacek]

Blogs are not a consistently reliable source, particularly for notability claims. It depends on the subject and on the blog. I'm not making this up; I spent a year doing AfD patrol, and this was probably the most frequently debated point in AfD arguments.

Obviously, they can't always be WP:RS, because then literally everything would be "notable", since anyone can stand up a blog about anything. You can't even logically assemble the argument you're trying to make.

[bjourne]

I didn't claim that blogs were consistently reliable sources. I claimed that they were routinely used as evidence of notability. Evidence of notability != Reputable source.

I'm not making anything up either; I have penned several articles on Wikipedia and gotten them through the AfC process with much less notability evidence than the Apache Arrow draft had. The difference was that I used to be an established contributor so the rules were not as harsh against we as they are against newbies and unknown contributors.

Also, you can look at the link I gave you and see that the notability rules are not uniformly applied.