Feature flags in Microservices - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a feature flag in software development?

A feature flag is a toggle that allows developers to turn features on or off without deploying new code. It helps control feature rollout and testing in production.

intermediate

How do feature flags help in microservices architecture?

Feature flags enable independent control of features in different microservices, allowing gradual rollout, A/B testing, and quick rollback without redeploying services.

intermediate

What are common types of feature flags?

Common types include:<br>1. Release flags - control new features rollout.<br>2. Experiment flags - for A/B testing.<br>3. Ops flags - for operational control like disabling features during outages.

advanced

What is a key challenge when using feature flags in distributed systems?

Ensuring consistent flag state across all microservices and avoiding stale or conflicting flag values is a key challenge in distributed systems.

beginner

Why should feature flags be removed after use?

Old feature flags add complexity and technical debt. Removing them keeps code clean and reduces risk of unexpected behavior.

What is the main purpose of a feature flag?

A To manage database connections

B To store user data securely

C To monitor system performance

D To toggle features on or off without redeploying code

Feature flags allow toggling features without new deployments.

Which type of feature flag is used for A/B testing?

A Release flag

B Ops flag

C Experiment flag

D Security flag

Experiment flags enable A/B testing by controlling feature exposure.

What is a common risk of not removing old feature flags?

A Increased technical debt

B Reduced code complexity

C Improved system performance

D Better feature rollout

Old flags increase technical debt and complexity.

In microservices, what is a challenge when using feature flags?

A Ensuring consistent flag state across services

B Writing SQL queries

C Managing user authentication

D Scaling database storage

Distributed systems must keep flag states consistent to avoid errors.

Which feature flag type helps disable features during outages?

A Release flag

B Ops flag

C Experiment flag

D Security flag

Ops flags control operational aspects like disabling features in emergencies.

Explain how feature flags improve deployment and testing in a microservices environment.

Think about how toggling features helps avoid full redeployments.

Describe best practices for managing feature flags to avoid technical debt.

Consider how old flags affect code quality.