the-algorithm/pushservice
twitter-team fb54d8b549 README updates
- renames pushservice readme.md to README.md
- Minor changes to main README.md
2023-05-22 16:11:33 -05:00
..
src/main Open-sourcing pushservice 2023-05-19 16:27:07 -05:00
BUILD.bazel Open-sourcing pushservice 2023-05-19 16:27:07 -05:00
README.md README updates 2023-05-22 16:11:33 -05:00

README.md

Pushservice

Pushservice is the main push recommendation service at Twitter used to generate recommendation-based notifications for users. It currently powers two functionalities:

  • RefreshForPushHandler: This handler determines whether to send a recommendation push to a user based on their ID. It generates the best push recommendation item and coordinates with downstream services to deliver it
  • SendHandler: This handler determines and manage whether send the push to users based on the given target user details and the provided push recommendation item

Overview

RefreshForPushHandler

RefreshForPushHandler follows these steps:

  • Building Target and checking eligibility
    • Builds a target user object based on the given user ID
    • Performs target-level filterings to determine if the target is eligible for a recommendation push
  • Fetch Candidates
    • Retrieves a list of potential candidates for the push by querying various candidate sources using the target
  • Candidate Hydration
    • Hydrates the candidate details with batch calls to different downstream services
  • Pre-rank Filtering, also called Light Filtering
    • Filters the hydrated candidates with lightweight RPC calls
  • Rank
    • Perform feature hydration for candidates and target user
    • Performs light ranking on candidates
    • Performs heavy ranking on candidates
  • Take Step, also called Heavy Filtering
    • Takes the top-ranked candidates one by one and applies heavy filtering until one candidate passes all filter steps
  • Send
    • Calls the appropriate downstream service to deliver the eligible candidate as a push and in-app notification to the target user

SendHandler

SendHandler follows these steps:

  • Building Target
    • Builds a target user object based on the given user ID
  • Candidate Hydration
    • Hydrates the candidate details with batch calls to different downstream services
  • Feature Hydration
    • Perform feature hydration for candidates and target user
  • Take Step, also called Heavy Filtering
    • Perform filterings and validation checking for the given candidate
  • Send
    • Calls the appropriate downstream service to deliver the given candidate as a push and/or in-app notification to the target user