How do engineers keep themselves updated?

By focusing on the fundamentals and not much on technologies themselves. Once you become good at fundamentals, you will start thinking of how something could be implemented under the hood upon the first sight itself.

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For industry news and conceptual thinking finshorts (podcast), the ken, paras chopra newsletter, grapevine

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You don't need to stay updated, sure it helps but if you grasp the overarching principles of your field (architecture in be, state management in fe etc) is all you need. When the necessity arises you can research and play around with all these tools, its mostly about reading documentation.
Having technical liberty at work helps alot.

Newsletters, hackernews, some community over discord or similar platforms, follow known industry leaders, etc. lots of ways but we cannot keep up everytime. Some work has to come ur way in that tech so that u really learn

First, have interest