API versioning for services in Microservices - Practice Problems & Coding Challenges

Challenge - 5 Problems

🧠 Conceptual

intermediate

Why use API versioning in microservices?

Which of the following is the main reason to implement API versioning in microservices?

A To improve the speed of the network between services

B To reduce the number of microservices in the system

C To allow clients to continue using old API features while new ones are added

D To encrypt the data sent between services

💡 Hint

Think about how changes in APIs affect existing clients.

API versioning allows backward compatibility so clients using older versions do not break when new features or changes are introduced.

❓ Architecture

intermediate

Common API versioning strategies

Which of the following is NOT a common strategy for API versioning in microservices?

A Header versioning (using custom headers)

B Database schema versioning

C URI versioning (e.g., /v1/resource)

D Query parameter versioning (e.g., ?version=1)

💡 Hint

Focus on how the API version is communicated to the client.

Database schema versioning is about data storage, not about how clients specify API versions. The other options are common ways to version APIs.

❓ scaling

advanced

Scaling challenges with multiple API versions

What is a major challenge when supporting multiple API versions in a microservices environment?

A Increased complexity in maintaining and deploying multiple versions simultaneously

B Elimination of the need for load balancers

C Automatic database migration for all versions

D Reduced network latency due to versioning

💡 Hint

Think about operational overhead when many versions run at once.

Supporting multiple API versions increases maintenance effort, testing, and deployment complexity because each version may require separate handling.

❓ tradeoff

advanced

Tradeoff of URI versioning vs Header versioning

Which statement best describes a tradeoff between URI versioning and Header versioning for APIs?

A URI versioning is easier for caching and routing, but Header versioning keeps URLs clean and RESTful

B Header versioning is easier for caching, but URI versioning hides the version from clients

C URI versioning requires clients to send custom headers, Header versioning uses URL paths

D Header versioning is deprecated and should never be used

💡 Hint

Consider how URLs and headers affect caching and readability.

URI versioning makes it simple for caches and routers to distinguish versions, but adds version info to URLs. Header versioning keeps URLs clean but can complicate caching.

❓ estimation

expert

Estimating storage impact of API versioning

A microservice stores user profiles and supports 3 API versions simultaneously. Each version stores 1MB of user data per 1000 users. If the service has 1 million users, approximately how much storage is needed to support all versions?

A 30 GB

B 3 TB

C 300 MB

D 3 GB

💡 Hint

Calculate storage per version, then multiply by number of versions.

1MB per 1000 users means 1000 MB (1 GB) per 1 million users per version. For 3 versions, total is 3 GB.