How to Lead Technical Discussions Without Being the Official Tech Lead?

The main thing I am looking for in a lead is control. Do they exert it in a firm but polite way? If someone is showing that influence, I'm happy to follow them as the lead in that particular scenario, even if they don't have the title. I worked at Meta where every engineer was purposefully title-less, so I'm used to that culture haha.

So how do you do that? There's a lot of things (this can be an entire course), but here's what I recommend:

1. Set the agenda for the meeting before it happens (fill in the meeting notes doc)
2. Create an awesome pre-read. For big technical decisions, you should probably make a system design doc to transfer context async beforehand and to anchor the meeting.
3. When the meeting starts, announce the purpose clearly, e.g. "For this meeting, we are going to decide on the security protocol for project X".
4. Time-box everything and communicate that. Have a roadmap in mind for how the cadence of the meeting should go, e.g. "For the first 15 minutes, let's flesh out the API and for the last 15 minutes, we need to figure out GDPR".
5. Police the meeting. If people go off topic and the meeting starts rabbit-holing on some random tangent, bring the focus back, e.g. "This is a great discussion, but let's table that for next time as we still need to figure out the API and we only have 5 minutes left".

Hope this helps!