General description
Describe, what is general intention of the component. What is its aim.
Context
List of the component communication with outside world. What commands/events/snapshots it sends, what messages it listens to, what rest services it offers, what services it consumes. And general description, why this connection is used. Don’t forget DB. 
For each communication channel describe (current situation):
Idempotency & retryability - whether is channel idempotent and in case of failure it retries if it makes sense.
Communication patterns - is it Synchronous? Asynchronous? Callback? Fire & forget?
Communication protocols - in our case Kafka/Rest over http/JDBC
Transaction processing
Describe, how TX (software dev meaning) are implemented ( eg. controller or service level, declarative, repositories TX.Mandatory? etc)
Scalability
Whether there are some limitations to number of instances running. Relation to Kafka consumer groups.
Approach to security
Most likely mention using of authorisation library for REST and rely on Kafka as always authorised calls…
Domain model
Please ideally use Draw.io and make the model “high level”. This means to put there just core entities. On top of that, describe their purpose by text below diagram itself.
Current technical debt
What in terms of code improvements and NFRs is currently missing and could or should be improved. Feel free to put Jira issues here if applicable.