Does being an engineering influencer help with career growth?

For most people, I would not recommend "engineer influencer" as a goal in itself. If you're in a Big Tech co and your primary goal is to climb the ladder to the Staff level, you definitely don't need to become a public influencer. You need to be known well around your organization, but that certainly does not require a large audience on LinkedIn or GitHub.

Unless your work naturally leads to you having an external presence (and aligns with your strengths), I'd focus on your company work. Having an external brand becomes more important as you get to very senior levels (e.g. a Google or Intel fellow must be known across the industry), or if you're trying to get hired in at an executive level.

I'll also note that the activities you mentioned are very different platforms and content:

• GitHub is usually the most closely linked to our day jobs as software engineers, since it's related to code. But it's quite hard to get discovered unless you're big on another platform. (Most of my GH followers came from YouTube)
• Blog posts are a great option, but again, it's very hard to gain any kind of distribution. I'd write blog posts as a way to reflect on what you've learned, and the bonus is that you have a body of work that someone could go through.
• LinkedIn is the easiest to get distribution on (see the case study from Alex on getting 2M+ impressions per month), but it's also the least technical. LinkedIn has more-or-less become like any other social media, which means it has lots of frivolous content along with career content.

The negatives:

• Your coworkers may judge you. Creating content is an odd choice, especially among a group of well-paid people (SWEs). Your coworkers may assume you're not serious about your job, or you're using the team/company for personal benefit.
• It takes time. This is valuable time that could be used to contribute more directly to the team or company goals.

The positives:

• You get tons of inbound opportunities, sometimes from people who are very interesting and smart.
• You get daily or weekly messages about how something you've created (either a video or post) has helped someone.

I really like Brian Jenney's perspective on the value of building in public and why your goal is not to get likes or engagement: Why It's Better To Share.

I have done my fair bit of "influencing" with over 100k combined followers, 7m+ impressions on LinkedIn, TikTok, Quora etc. I'll keep it short in a pros/cons list.

Pros

• Social impact: absolute #1 for me, being thanked by individuals I impacted or uplifted.
• Writing/speaking/articulation/confidence/creativity: qualities all good leaders need. Based on the medium, you will have a chance to build all of these qualities.
• Connections: chance to meet other influential and fun personalities (like Rahul).
• Side-hustle: Personally, I have had a strong principle to not make any money from my mentorship initiatives; and I donate 100% if I do make nominal amounts. Some people do make a few hundred bucks per week/month though.

Cons

• Takes time: certainly takes good amounts, will have to cut from either life, or work, or time you could've spent learning.
• Vanity metrics: you may get attached to the "wrong" metrics (follower counts, etc.) and soon it'll be a toxic relationship with social media.