Messaging system of partial and out-of-order events

1 . A method, comprising:

receiving, via an Application Programming Interface (API), a message that includes a timestamp;

determining that the message is an out-of-order event message based on the timestamp; and

placing the out-of-order event message in a queue of messages based on a priority level assigned to the out-of-order event message.

2 . The method of claim 1 , wherein the queue of messages comprises a plurality of event messages, comprising:

assigning a priority level to the out-of-order event message based on a priority rule from a plurality of priority levels; and

sorting the plurality of event messages and the out-of-order event message based on the plurality of priority levels assigned to the plurality of event messages.

3 . The method of claim 2 , wherein the plurality of priority levels indicates a chronological order in which the plurality of event messages is sent from one or more client devices.

4 . The method of claim 1 , wherein the out-of-order event message is a first out-of-order event message, comprising:

receiving a second out-of-order event message;

identifying content data associated with the second out-of-order event message; and

determining that the content data indicates a data item associated with the second out-of-order event message is missing.

5 . The method of claim 4 , wherein the second out-of-order event message is received via the API.

6 . The method of claim 4 , comprising:

determining that the data item can be fetched from a database;

fetching the data item from the database; and

placing the second out-of-order event message in the queue of messages.

7 . The method of claim 4 , wherein the queue of messages is a first queue of messages, comprising:

determining that the data item cannot be fetched from a database; and

placing the second out-of-order event message in a second queue of messages, the second queue of messages being associated with a lower priority ranking in processing compared to the first queue of messages.

8 . The method of claim 7 , comprising:

receiving the data item associated with the second out-of-order event message; and

placing the second out-of-order event message in the first queue of messages for processing.

9 . The method of claim 1 , wherein the out-of-order event message comprises an entity identifier associated with a user that is absent from a conversation, comprising:

determining a data item associated with the out-of-order event message is missing, the data item corresponding to a system notification that indicates the user has left the conversation.

10 . The method of claim 9 , comprising:

determining that a user profile associated with the user can be fetched from a database;

fetching the user profile from the database;

generating the data item based on the user profile; and

writing the out-of-order event message to the database based on the data item.

11 . A system comprising:

a memory storing instructions; and

one or more hardware processors communicatively coupled to the memory and configured by the instructions to perform operations comprising:

receiving, via an Application Programming Interface (API), a message that includes a timestamp;

determining that the message is an out-of-order event message based on the timestamp; and

placing the out-of-order event message in a queue of messages based on a priority level assigned to the out-of-order event message.

12 . The system of claim 11 , wherein the queue of messages comprises a plurality of event messages, and wherein the operations comprise:

assigning a priority level to the out-of-order event message based on a priority rule from a plurality of priority levels; and

sorting the plurality of event messages and the out-of-order event message based on the plurality of priority levels assigned to the plurality of event messages.

13 . The system of claim 12 , wherein the plurality of priority levels indicates a chronological order in which the plurality of event messages is sent from one or more client devices.

14 . The system of claim 11 , wherein the out-of-order event message is a first out-of-order event message, and wherein the operations comprise:

receiving a second out-of-order event message;

identifying content data associated with the second out-of-order event message; and

determining that the content data indicates a data item associated with the second out-of-order event message is missing.

15 . The system of claim 14 , wherein the second out-of-order event message is received via the API.

16 . The system of claim 14 , wherein the operations comprise:

determining that the data item can be fetched from a database;

fetching the data item from the database; and

placing the second out-of-order event message in the queue of messages.

17 . The system of claim 14 , wherein the queue of messages is a first queue of messages, and wherein the operations comprise:

determining that the data item cannot be fetched from a database; and

placing the second out-of-order event message in a second queue of messages, the second queue of messages being associated with a lower priority ranking in processing compared to the first queue of messages.

18 . The system of claim 17 , wherein the operations comprise:

receiving the data item associated with the second out-of-order event message; and

placing the second out-of-order event message in the first queue of messages for processing.

19 . The system of claim 11 , wherein the out-of-order event message comprises an entity identifier associated with a user that is absent from a conversation, and wherein the operations comprise:

determining a data item associated with the out-of-order event message is missing, the data item corresponding to a system notification that indicates the user has left the conversation;

determining that a user profile associated with the user can be fetched from a database;

fetching the user profile from the database;

generating the data item based on the user profile; and

writing the out-of-order event message to the database based on the data item.

20 . A non-transitory computer-readable medium comprising instructions that, when executed by a hardware processor of a machine, cause the machine to perform operations comprising:

receiving, via an Application Programming Interface (API), a message that includes a timestamp;

determining that the message is an out-of-order event message based on the timestamp; and

placing the out-of-order event message in a queue of messages based on a priority level assigned to the out-of-order event message.