What are some methods or tools, apart from interviews & surveys, you use to research and understand customer needs in-depth?

If you’re collecting product usage data I would look for the sticky parts and the untouched parts of the platform that your data shows should be valuable. Where do people dwell—is it because that part of the platform is hard to understand or because they get the most value from it? What’s missing from their daily workflows? Why?

Look at your support tickets as well. Where are people getting stuck or losing speed? Is there an education gap or a product gap?

I would also consider a customer CAB or PUG (power user group) to get continuous feedback from your users.

Guided deliberation is a great methodology. You take 4-6 people and divide them into two camps. One camp is pro one solution, and the other camp is advocating for another. You have them debate their positions and work to reach a consensus. It taps into much deeper thinking than what you typically get in interviews and illuminates drivers and barriers.

There are a few other analyses that I use to research and understand customer needs. One of them is leveraging the data you already have from various customer segments, which is a good start to better understand your customers' needs. By examining how different segments engage with your product, you can gain valuable insights into the actual value they derive from it. This includes customer journey mapping and customer LTV analysis.

Customer support tickets are great assets to understand your users needs and can definitely guide you to enhance your products based on real user feedback.

In case you haven't done so yet, I highly recommend conducting a JTBD analysis that involves customer observation, which enables a deep understanding of the jobs your customers “hire” [or "fire"] your product to do and assesses how well it performs in those roles. Substitute and competitive analysis is an additional strategic method to better comprehend customer preferences and identify gaps in your products. Win/loss analysis is particularly effective in highlighting customer preferences.

Through usability testing I identify usability issues, understand user preferences, and ensure the product aligns with customer needs.

I hope this answers!