The value of in-house expertise

An alternate title for this post might be, "Twitter has a kernel team!?". At this point, I've heard that surprised exclamation enough that I've lost count of the number times that's been said to me (I'd guess that it's more than ten but less than a hundred). If we look at trendy companies that are w...

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Hasnain says:

Great read on in house expertise and the value of building vs buying in the right scenario.

“Before the patch, if you profiled our Scala code, you would've seen an unreasonably large amount of time spent in Future/Promise, including in cases where you might naively expect that the compiler would optimize the work away. One reason for this is that Futures use a compare-and-swap (CAS) operation that's opaque to JVM optimization. The patch linked above avoids CAS operations when the Future doesn't escape the scope of the method. This companion patch removes CAS operations in some places that are less amenable to compiler optimization. The two patches combined reduced the cost of typical major Twitter services using idiomatic Scala by 5% to 15%, paying for the JVM team in perpetuity many times over and that wasn't even the biggest win Flavio found that year.

I'm not going to do a team-by-team breakdown of teams that pay for themselves many times over because there are so many of them, even if I limit the scope to "teams that people are surprised that Twitter has".”

Posted on 2021-09-29T15:32:15+0000