[ClikeX]

The only limiting thing I've experienced with ActiveRecord is when the database becomes larger and more complex. The performance takes a bit of a hit. Which isn't ActiveRecords fault, it's the developer's lack of understanding how the database works.

Most of the issues I see is a lack of understanding of things like N+1 queries. I see this mistakes from junior to senior level. ActiveRecord has built in solutions to fix them too. Some developers don't know about them.

[yxhuvud]

There are built-in solutions but also quite severe limitations when you get to advanced usage of activerecord. Especially with regards to composability. Of course, raw SQL is also really bad in that scenario.

[tylerhou]

When I found ActiveRecord insufficient, I found it easy to drop down to Arel for complex queries: https://www.rubydoc.info/gems/arel