There are many paths to implement feature flags with varying logistical considerations and return on investment. The path to take depends on your team's needs and organizational goals.
Feature flagging has some infrastructure dependencies that need to be addressed to function properly. As teams scale their use of feature flags and the switching on/off of flags becomes a business decision, it becomes critical to have an authoritative data store and a management mechanism for the flags. Many third-party feature flag services provide this data store dependency.
Third-party hosted feature flag services are often the best solution. They handle the heavy logistics, and offer easy-to-integrate libraries that expedite the installation process. This allows teams to focus on core business duties instead of infrastructure management. However, if your team has third-party security concerns, it may be in your best interest to implement your security flag backend.
Separately, engineers need to instrument new code logic that retrieves the flag state from the service to activate the flagged content. This requires code merges and deployments of the flag code before it’s activated. Since many feature flags are temporary, don't forget to remove the feature flags that are no longer necessary.