How do you coordinate with other teams in software deployment?

In my experience, your have to understand the need, opportunity or pain point you are trying to address and for whom. Whats the scale of problem now and anticipated in future? What tech debts you need to consider in the impacted area? I use the lean canvas, big picture event storming, sample user journey embellished with real world scenarios to frame and refine the problem. You also need to understand cost of delay, mvp scope and future business roadmap so that you refine the thinest slice but keep a wider perspective.

Once you understand the problem and know the scope- it is important to refine the key change, the assumptions and understand the full end to end impacts. You need to ensure that before the build begins, the dependencies are known and accepted, the quality assurance approach is refined, the non functional requirements are considered. Continuing from Discovery, for complex scenarios, it is good to have examples to explain various permutations, combinations in scope so that the build is complete. Not forgetting, negative scenarios. Usually, visual wireframes, swim lane diagrams etc. work well to explain the exchange. where apis are involved, its important to discuss swagger schemas, api resources, resource models etc.

As we devise the deployment Strategy, we need to also define the interface agreements for all systems part of architecture. Having a thorough interface agreement helps identify and eliminate any unknowns before we prepare for launch.

A very simple way to have a concrete Strategy is to have a thorough deployment plan documenting every step in the process. Spending time in listing all tasks will bring immense confidence going into the deployment and we can time box every step. This will help to identify any deviation from deployment plan as well

This is usually owned by the delivery managers, scrum masters etc. via status reports, synch stand ups, daily stand ups etc. For companies that use SAFe, PI planning helps start the process, which is then monitored in various synch up meetings. For others, it can be part of the project plan with key milestones and dependencies called out. The key watch out here is when there is work across organisations and there is no joint plan which causes friction, errors, delays when systems fail to communicate. Whats worked for me in the past, is using a joint plan of activities, using sample data in test environment for the full e2e including any 3rd party organisations involved and constant communication to ensure successful deployment

Watch out here is to ensure you have a clear alignment of the outcome you wished to achieve and was that met or not. Whilst all feedback is useful, it is important to consider that against business priorities to validate if this feedback or finding needs to be considered immediately, or added to backlog or is not relevant to what your product is trying to deliver.

This is when you need to be aware of what else is happening in your organisation that could impact your deployment and ensuring that those items are assessed and their impact validated before choosing a deployment date.

Given the headline is coordinate. I would say agreeing both the collaboration tool and rules of engagement for using the tool. Specifically a DevOps tool such as Azure, Apache, SysAid for example.