[Illniyar]

What is a lead developer in this context? An engineering manager? Is it like an architect (staff engineer/whatever)? An engineer who is in charge of a specific project?

There are different dynamics at play in each role and reading the guy's bio I'm getting the sense that he is a freelancer? or has a consulting company? which would have a whole different dynamic.

[kenhwang]

The lead developer is the person assigned to the lead developer role. I know it's cheeky but it really could be anyone. It's usually at least a senior-level individual contributor (IC). It's not uncommon for it to be a manager (that hopefully used to be an IC).

The lead's authority also tends to be varied in scope. They could be the lead of the feature, project, repo, team, initiative, or org. Depending on the context, their hierarchy might not always be the same.

So really, a lead is someone that is in or uses leadership within their scope and with others in the same position. Alternatively referred to as "politics".

In this context, they're handing the politics of development issues with the goal of getting features done.

[gwbas1c]

In the aerospace world, it's called a "systems engineer."

The lead:

1: Understands the whole system, but not necessarily every detail.

2: Plans the whole project.

Edit:

Sometimes in the software world, the title is "architect."

This is rarely the "manager," except in organizations that have a hard-on for hierarchy and artificial promotion for "career advancement." Managers are usually concerned with people, schedules, and resources; but don't go very deep into technical issues.

That being said, the lead/manager may fill in for each other when one is on vacation, sick, quits, ect.