How would you handle a situation in which your manager is dissatisfied with your performance?

I would have detailed discussion about the area of improvement. I would go do a self retrospective on the projects, deliverables, behavioral aspects where I lacked and needed to do better. I will note down those things and come with a plan on how I plan to close the gap and share that with my manager. I will be extra conginizant going forward in those situation to make sure i do not repeat the same behavior and demostrate the actions pointed out as gaps. In my next few 1:1 try to gather constant feedback from manager on how he percieves the change and how I can improve it further. Also gather feedback from peers about the same to have incremental improvement. 

When I get a feedback which from my manager on areas of improvement, I follow these process:

a) Take in the feedback

b) Reflect on what went wrong and how I could improve.

c) Come up with a way to improve the next time

d) Clearly communicate on my introspection and get an approval on m new approach

e) Regularly bring this up in 1:1 to make sure that I course correct and improve my performance.

At Centercard while I was a director of Technology, my CTO asked me to come up with a strategy to enhance our monitoring and alerting process - as there were some gaps for e.g. I failed to document the escalation approach when a service is failing in production. I failed to do a deep dive and presented a stratergy which had gaps in it. My CTO was not happy with this and asked me to rework. I went back, accessed what was missing - collobrated with other eng. teams and came up with a comprensive approach and got it approved by my CTO. The lesson I learnt was that I needed to take a wholistic approach of my work and not just siloed approach.