I'm working at a start-up, and a first PM hire; what KPIs should I own and not own?

Don't think of it of what you should and should not own. Think about what makes sense to the customers you are focusing on. Then think about where you are in the customer/product lifecycle and product/market fit. What does the overall business care about at this time (e.g. retention vs. acquisition) and start seeing how your product area could contribute back to that overall goal.

Congratulations! I’ll answer your question with a few questions of my own.

1. Purpose: What do you want to drive? What does your organization expect you to own? In Product Management there is a lot of autonomy, but it can also feel tempting to take on everything that needs an owner.
2. Outcomes: If you don’t own a specific KPI, what will happen? In a year, will this KPI matter? What about in 3 years? Does the KPI support the goals of the business in a real way?

I’d recommend starting with 2-3 target KPIs that tie directly to your purpose. From there, make the targets visible through dashboards or reports and constantly revisit them. Ask your colleagues for feedback, and never be afraid to make adjustments! 

Also, try to be aware of the impact these measurements are creating. Do you find yourself referring to these targets often, do they impact decision making? One of my colleagues likes to say the best way to know if a report is useful is to stop sending it and see what happens. 

• Congratulations to you! There are a lot of ways you can pave the path for KPI's at your company as the first hire
• The KPI's should be directly based on the business outcome you plan to achieve.
• Even before that though, I would highly recommend having a solid Product Vision and Strategy in place for your company/product
• Who are your customers? What is the benefit you are trying to provide them?
• After that you can use the AARRR (Acquisition, Activation, Retention, Revenue, Referral) framework to understand the best metrics you can choose to align with this outcome/goal
• Picking a certain number of KPI's is also an art. I would recommend sticking to 2, max 3 that you really feel give you a good sense of the business and how impactful it is for the end user/customer
• Generally PM's would own Company, Business, Acquisition, User Engagement and User Satisfaction KPI's. Examples are: MRR, Churn rate, Number of users, DAU/WAU/MAU, Number of sessions, Session duration, Churn rate, NPS or CSAT etc.

In a startup, PMs have additional responsibility in ensuring success of the product and customers. My suggestion would be to focus on customer satisfaction, success/retention and support satisfaction.

KPIs like

1. Active users

2. MRR

3. ARR

4. Speed to resolution on Support ticket and its Life cycle KPIs

5. Customer Acquisition cost

These parameters will help give the teams to take data driven decisions crucial for navigating a startup to success