They could have just used different Java/Python libraries and changed the architecture for the same result. The choice of a Programming Language alone has minimal impact on performance at that scale.
> They could have just used different Java/Python libraries and changed the architecture for the same result.
Yep, their blog post is carefully worded to say "The combined effect of better architecture and Elixir" but they didn't mention how much of it is related to architecture or what specifically they did with Elixir to make things faster. It feels like a marketing piece for their consulting services.
I mean they put:
> Rewrote an #AWS APIGateway & #lambda service that was costing us about $16000 / month in #elixir. Its running in 3 nodes that cost us about $150 / month
They saved 100x here by moving from an expensive architecture (Serverless lambdas) to potentially reserved instances which are reasonably affordable, at least for cloud standards.
I remember once needing to parse XML in Python. I started with the easy approach of using the first XML parsing library I found which was xmltodict. Eventually I stumbled upon lxml which improved overall performance by 20x and I didn't have to rewrite much code at all. Sometimes it's easy to get big wins in your existing language if you know what the problem is.
Rewrite would give you a more optimized code almost always, because you know what you are writing.
Though the article says that they rewrote the notification system, and erlang/elixir is pretty amazing for that stuff. From the point "memory footprint per long-running connection".
I mean there are plenty of examples in the wild left and right.
Have you ever seen basic db optimization? Alone in my companies people were just using stuff wrong.
Performance and Architecture are a after thought in our industry. A normal developer doesn't think about it.
There was one query in my company which was running in one region slower than in another one and there was also an explain statment available. No one looked at the explain statement and thought "huh why does this simple select use so much memory". People weretrying to see why the regions themselfs were different not what the problem with the query was.
