Is SDE to TPM a good career switch?

Are TPMs more prone to lay-offs?

I personally think so - Similar to other roles with an "M" in it, TPMs aren't builders on their own. They work through engineers. In Meta's most recent layoff wave, I heard it was literally all TPMs.

How tough is the switch from TPM back to SDE in case I don't like the TPM role later?

It will be hard. SWE -> TPM should be pretty straightforward since you have the coding background to speak the language of the engineers you're managing (this gives you an edge over other TPMs). TPM -> SWE is trickier, especially if you have been TPM for a long time, as people will be skeptical of your technical abilities.

In general, it's easier to go from coding -> non-coding than the other way around. Make these transitions carefully.

Are TPMs less respected than SDEs? I have this fear that this switch might be career suicide for me.

It depends on who you ask. 😉

If you want to learn more about TPMs, check this out: Technical Program Manager (TPM) resources

How tough is the switch from TPM back to SDE in case I don't like the TPM role later?

This is the sticking point for me -- there's less optionality as a TPM. Unless you're very diligent about keeping up technically, you'll start to get pigeonholed as a TPM and won't be taken seriously for eng roles.

This depends on the strength of your network and how many people can really advocate for you.