Rails Performance and Scaling

Discussions center on the performance limitations, scaling challenges, and resource inefficiency of Ruby on Rails applications under high loads, including debates on Ruby's GC issues, comparisons to alternatives like Go or Java, and examples from large-scale deployments.

📉 Falling 0.3x Web Development
2,921
Comments
20
Years Active
5
Top Authors
#7768
Topic ID

Activity Over Time

2007
39
2008
108
2009
139
2010
173
2011
216
2012
210
2013
448
2014
180
2015
97
2016
126
2017
104
2018
126
2019
92
2020
122
2021
117
2022
201
2023
193
2024
120
2025
103
2026
7

Keywords

RAM CPU TechEmpower WL3 AWS FP harvard.edu node.js EventMachine JVM rails ruby scaling performance unicorn web app stacks server ruby rails

Sample Comments

EdSharkey Jul 10, 2018 View on HN

Didn't Rails have all kinds of scaling issues for non-trivial apps and loads?

0x420 Mar 6, 2014 View on HN

Rails is slow enough to begin with.

fsniper May 19, 2024 View on HN

Am I missing something? Or is rails really really expensive and inefficient?

dmux Nov 24, 2025 View on HN

Here's another thread talking about IO- vs CPU-Bound Rails apps from 10 months ago: https://news.ycombinator.com/item?id=42820419

endorphine Jun 23, 2022 View on HN

Isn't the typical Rails app IO-bound?

Arnor Jun 17, 2015 View on HN

How significant is the performance impact on a mid-large Ruby on Rails application?

stouset Jan 26, 2024 View on HN

If your application can’t saturate the CPU, Rails probably isn’t your bottleneck.

agentbleu Feb 12, 2008 View on HN

anyway forgive me but I was under the impression RoR had performance issues?

pcowans Feb 23, 2009 View on HN

Rails running on vanilla Ruby does have particular scaling issues due to the limitations of the Ruby garbage collector. You hit a GC cycle after every 8MB of allocation, which typically takes around 150ms to run, so can dominate the runtime of your requests. We've had 80% of the runtime in GC, even when you include database time.This isn't necessarily a killer, but it means there's sometimes more work than you might like in scaling. There are patches to tune the garbage collector, and JRuby e

ngrilly Oct 14, 2024 View on HN

Ruby on Rails is not known for being very RAM efficient, but this is only me speculating.