Usage of CQRS and event sourcing at Maxwell Health.

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6. Generation
A data change or action
results in generation of
event messages, which
are blobs of JSON.
Example changes:
● Changing a user’s
phone number
● Purchasing
benefits
● Adding a
dependent to a
medical plan
Queueing
After a data change or
action is completed,
event messages are
written to a queue.
Processing
An event message
processor consumes
event messages from the
queue and processes
them. Event messages
are then written to each
consumer/projection.
Consumption
Most projections receive
event messages by
consuming them off of a
queue. An example of a
projection is the
Reporting service which
listens for and processes
event messages to build
out a domain specific
database.

7. Type: memberNameUpdated
Id: 123
NameFirst: “John”
NameLast: “Smith”
TimeStamp: 1
Time
Type: memberCreated
Id: 123
TimeStamp: 1
Type: memberPhoneUpdated
Id: 123
PhoneHome: “555-555-5555”
TimeStamp: 4
Type: memberQleCreated
Id: 987
MemberId: 123
Type: “marriage”
TimeStamp: 3
Member record from source
QLE record from source

8. Type: memberAddressUpdated
Id: 58a74fb59b2212961a1f217f
AddressCity: Boston
AddressState: MA
TimeStamp: 1515176147.3453
MySQL table: member_snapshots

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