How does one gauge autonomy in a product marketing interview?

As you can probably tell, I am a big fan of focusing on process, not just outcomes. I like to ask people to walk me through a project they led, and I ask them plenty of questions — things like 'why did you decide to position it that way?' or 'what was the most difficult part of the process, and how did you handle it?'

Usually when you dig into the details it becomes apparent whether they led the work autonomously or just played a small part. 

I'm also a big fan of hypotheticals. I give someone a scenario that is well within the scope of what they would be doing in the role, give them plenty of background context (and make sure they know they can ask me for more information), and then ask them to walk me through how they would approach it. 

Note - I don’t always look for autonomy unless I believe it is a key requirement for the role. Many PMM roles require more execution skills, a hustle mindset and someone who can get things done - even if it requires a bit of handholding and coaching along the way

However, if autonomy is what the role demands , I try and suss it out by asking a ton of follow questions to standard behavioral questions. When a candidate explains a story/situation from their previous work experience, I often double click and ask questions like - “Tell me the process of how you arrived at that answer”, “How did the team build that campaign”, “What happened after the first meeting when this idea was proposed ? How was it put into action” , “Who was the project lead on this initiative ? What was your role in this ?” “How did you measure you were doing a good job? What would have happened if you didn’t meet this goal” and so on

Through questions like these, and more - I am trying to understand their role on the project. Are they the leader, the driver, the orchestrator, the project manager, or something else ? Are they working independently or constantly needing coaching ? Did they feel a sense of accountability and ownership to the discussion ? Were they responsible for the project success or simply around success ?

I think this is probably a question you can get a feel for by asking a few tangential questions: 

1. Asking questions that help you identify the hiring manager's style of management - are they hands-on or do they prefer to be more hands-off 
2. Asking questions to help identify the company culture. What are the expectations from the leadership team regarding reviewing projects, defining projects, etc? 
3. Asking for examples of previous Product Launches (for example) and what the DACI or RACI looks like - and what the role of a PMM is in driving the launch. 

tl;dr -- define what you need this person to do, then ask for specifics of opportunity identification and execution during the interview.

I think this really depends on the level of seniority/breadth of responsibility you're hiring for, so the first thing I'd recommend is getting crystal clear on what you actually need this person to do. Then I'd make sure that you are aligned with the recruiter on the req (if you have a recruiter) and the rest of the hiring panel all agree on what responsibilities and success look like for this role.

This is important because responsibility-relevant autonomy takes many forms. For example, if you're a 50-person startup making your first PMM hire you need that person to be able to develop a functional vision, establish an internal cross-functional operating model, and prioritize what to execute against given constrained resources and rapidly shifting needs of the business as it grows. This is very different from, say, what you'd need if you're hiring a fresh MBA to fill a role on your team at Microsoft -- especially so since at a larger company this person might be more responsible for coordinating external contractors than on the line execution.

Once you and your team are aligned, the best way to gauge autonomy is to ask someone to walk you through an impactful project they're proud of that reflects their work. Make sure to use follow-ups to:

• Zero in on their impact by changing from "we" to "I" pronouns
• Press on end-to-end contribution: 
• Who came up with the idea for the project? Did they identify the opportunity and if so how, or were they told to work on this?
• Who made the process/plan for bringing it to life?
• Who did they work with cross-functionally, and who was playing what kind of roles?
• How did they assess whether or not it was successful?
• How frequently did they need to check in with their manager for guidance/problem-solving?

The more specifics you can get to the better! Further, it's usually a sign of autonomy and leadership that the person will naturally be forthcoming with some if not all of the above bullets without too many follow-up questions. If getting to answers for the above is like pulling teeth, this is probably not the right candidate for you.

If I understand the question correctly, you want to know if the candidate is an independent self-starter or requires more in-depth guidance and direction. Is that correct?

I would ask him/her what they consider to be a successful start to their new role and what their 30-60-90 day plan is to help them achieve that. An independent self-starter will probably have thought through some of that already.