Are layoffs random or can I do something to prevent getting laid off?

For the most part, the people cut in a mass layoff are arbitrary, or at least done with imperfect information. A mass layoff is obviously sensitive information, so it is done by a small group of leads who decide which teams are impacted. This small group of people is acting quickly and without the full information about each person's performance, so getting laid off ("RIF") is rarely a personal judgment.

Two concrete pieces of advice:

1. Leverage and build your network. The people who can best advocate for you + your skills are your (ex-)colleagues and people you've worked with.
2. Evaluate how critical is your team to the central function of the company. Do this exercise right now, and predict what will become important 2 years from now -- that's where the job security is.

(I don't think how much your manager likes you has that much impact in a mass layoff, but it could help in a localized layoff where teams have to fire the bottom 10% of the staff)

With tons of layoffs already happening and rumors about impending layoffs, is there something one can do to protect themselves?

Unfortunately, there isn't too much you can do as a rank-and-file employee here, but here's 2 core things you can control that come into the layoff equation:

1. Your performance - As you already alluded to, you want to make sure that you are as strong as possible here. Given that Meta has such a high bar when it comes to SWE performance and effectively revolves around PSC, I would be really surprised if this wasn't a factor.
2. Your relationship with your manager and skip - Front-line managers usually don't have a huge say when it comes to layoffs, but your skip could, especially if they're a director. Given that you're E5, having a good skip relationship is something you can feasibly do.

The good thing about the above 2 is that they are areas where you should already be strong at anyways, layoff climate or not. You don't need to massively warp your behavior to set yourself up well for layoffs.

Does it make sense to stay put within a team where you have great relationship with your manager and skip etc or find a new company to get ahead of this risk?

It depends, but in a vacuum, I heavily recommend sticking with your team and manager if you like them. People seriously underrate the value of a supportive team - The vast majority of engineering teams are bad. Even at prestigious companies like FAANG/FAANG-equivalent ones, it is super easy to end up on a bad team. I think the case for proactively finding other opportunities is if you're employment/compensation sensitive and you really can't take an employment gap (e.g. you are in the US on an employment visa).

I also recommend going through the following resources about layoffs:

• "How to survive potential layoffs?" - Another discussion started by a Meta engineer
• "What are the signs of an impending layoff in an organisation that can help an employee prepare themselves better?"

Lastly, I just want to say that you shouldn't stress out about this too much (easier said than done, of course). You're a senior engineer at one of the greatest tech companies in the world - I'm sure you can find a decent opportunity quickly if you were to get laid off (and the Taro Premium network can help a lot with that). Meta has also treated employees well historically, so I'm very sure that all laid off employees would get a great severance package.