IMO this person needs to come to Jesus or be fired.
> I'm the tech lead but not manager
You need to have a conversation with the manager. Document the violations of standards and company policy. The manager should review this with the problem employee, in writing, and the employee should sign an acknowledgement that the warning was received and understood.
If the employee does not improve he or she should be terminated. Such people are like cancers if they are allowed to remain unchanged.
Ideally the "large, famous" software company already has defined an HR process for managing situations like this.
If you can't get backing from the manager or the manager's manager then you need to think about whether you want to stay in a company that isn't giving you the support you need to be "responsible for the technical execution of the team and the success or failure on that level."
I will add to this that the OP should seek out or ask their manager to find a principal/staff level engineer that can take on the individual effort of helping the renegade engineer fall in line. That may be more in line with their responsibilities than a team lead.
Not at all, at least at FAANGs I was lucky enough to observe from the inside myself.
Team lead there is essentially a middle ground between the engineering manager and IC devs. Sometimes teams do with just ICs+manager, sometimes it has that TL layer in-between (usually on larger teams, either in the number of people or the scope of work). TLs can be either senior or staff engineers (only seen seniors as TLs though). Both senior and staff engineers can be either ICs or TLs.
Often, I see TL positions being either just a stop-gap for transitioning to being an engineering manager or as a lite test-drive of whether the person would actually like being in a management position (as opposed to an IC).
> I'm the tech lead but not manager
You need to have a conversation with the manager. Document the violations of standards and company policy. The manager should review this with the problem employee, in writing, and the employee should sign an acknowledgement that the warning was received and understood.
If the employee does not improve he or she should be terminated. Such people are like cancers if they are allowed to remain unchanged.
Ideally the "large, famous" software company already has defined an HR process for managing situations like this.
If you can't get backing from the manager or the manager's manager then you need to think about whether you want to stay in a company that isn't giving you the support you need to be "responsible for the technical execution of the team and the success or failure on that level."