Customer Success and Product Management are like two wheels of a bike. It is very important for both of these functions in an organisation to be in sync to ensure a smooth and seamless customer journey. Customer Success is all about coordinating with customers and solving their issues and pain points. As a CSM, you need to be in touch with your customers and show them the value of the product that they have purchased which is an important responsibility.
A product has multiple features, functionalities and settings which need to match with the customer's business model and overall needs, and a CSM needs to provide training on such aspects. It is really important for the CSM to focus upon the product adoption which would in turn help the customer to see the value in the product. This is the first instance where Customer Success and Product Management overlaps.
Secondly, there are various instances where the customers raise different queries. These queries encompass various issues  - like technical issues, product related issues and non-technical queries majorly. Here also the customer success team is actively involved because they need to get the issue resolved as soon as possible and need to make sure that everything is sorted out. This is the second instance where Customer Success and Product Management overlaps.
Moreover, there are instances where customers have some product feature requests and it is crucial that the customer success manager discusses this with the customer in great detail.  Once you have the details, you need to communicate with the product team about this. Basically, try to understand the feasibility of the product feature request and inform the customer accordingly. In case the team has decided to include it in the upcoming sprint, we need to talk about the timeline for this. Once you have an update, you need to complete the loop by getting back to the customer. This is the third  instance where Customer Success and Product Management overlaps.
Also, when there are new advancements in the product, it is very important for the product team to train their CSMs because CSMs are the ones who would take this feature to the customer and would have to train the customer ahead. This is the fourth  instance where Customer Success and Product Management overlaps.
The overlap of customer success and product management is seen at various circumstances and these teams need to work closely in order to make this a success for the customer. Since CSM is the face of the product, they need to coordinate on regular basis with the product team so that product can improve for the good. Also, instances where we receive good feedback from the customer on a product feature, the product team needs to be applauded for the same because at the end of the day, it’s the product that a customer uses and has paid for.
In conclusion, I would like to say that these two teams need to be in sync throughout and should man the fort together.