• Spring Boot with Reactive Web - reactive webclient for stream API handling, dependency injection, properties, etc.
• Kotlin Coroutines - API fetching non blocking way
• Resilience4j - Twitter complex retry policy handling, also other features if needed
• Wiremock - API integration testing - separate integrationTest profile and package
• Micrometer - tweets fetching related metrics gathering
• Jib plugin - generating secure, layered and bullet-proof docker image (I've also provided a Dockerfile as a second option)
• Gradle - building whole application
• Docker - application can be run as a docker container

Startup script is in build-and-run.sh file. It basically creates a docker image and runs it. You need to pass correct environment variables, especially:

• -e TWITTER_ACCESS_TOKEN=access-token \
• -e TWITTER_ACCESS_TOKEN_SECRET=token-secret \