Feature flag evaluation methods: Remote, Local, or Proxy – what’s right for you?

Feature flag evaluation methods—remote, local, and proxy—each have distinct advantages and disadvantages, making the choice of method crucial depending on the application's requirements, architecture, and performance needs. Remote evaluation involves making API calls to check feature flags in real-time, suitable for frontend applications and backends that can manage slight delays due to network dependency. Local evaluation is ideal for backend services and edge environments requiring fast performance without latency, although it requires managing and updating flag data locally. Using a proxy allows for data privacy by keeping evaluations within the infrastructure, beneficial for server-side applications concerned with security, though it adds complexity and potential bottlenecks. Ultimately, selecting the right method involves balancing trade-offs like latency, data privacy, and infrastructure complexity based on the application's specific needs and team priorities.