What learning and development (L&D) platforms have you found effective?

We have used several ones. If I have to recommend a L&D platform, I would say Coursera and LinkedIn Learning.

But more than the platform, the most important aspect is to have a good training strategy. Learning path, skills to be developed, etc.

-> Whatfix
-> Docebo
-> ProProfs

I have used these of which I would Docebo. It has effective ILT-Classroom, easy File Uploading and Converting, powerful Integrations with Popular Software, flexible settings and so on.

We currently use Coursera and in the past tested out LinkedIn Learning and Pluralsight.

All have their use cases with Pluralsight being a bit more focused. I think effectiveness often comes down to how motivated employees are to use the platforms and how specific the use case. If the goal is to learn a technical skill then they can be helpful but I don’t think I’ve ever seen one that works well for training related to soft skills. Of the three I find LinkedIn the most generic since it doesn’t have much in the of testing what you learned via projects or tests, but it’s also relatively inexpensive.

Linkedin Learning worked for our needs. 

Currently there are many learning and development platforms.
Almost all the ones I have had the chance to use are very good and effective. They use AI in order to offer a more personalized content depending on the user's profile.
I personally had a very positive experience with some of them, such as:
LinkedIn Learning

Vodafone University
GoToWebinar

Avado
For me, it is important to have the will, because there are plenty of resources, and almost all of them are very effective.