Vertical Scaling:?

Short answer: Scaling Up: This involves increasing the resources (CPU, memory) for a specific microservice instance.

Explain a bit more

Vertical scaling is more common for monolithic applications or services that require more powerful hardware but is less optimal for microservices due to their distributed nature. Example: Increasing the memory or CPU for a service like the Payment Service that requires more processing power. Best practice: For microservices, horizontal scaling is preferred because it increases resilience and fault tolerance by distributing traffic and workloads across multiple instances.

Real-world example (ShopNest)

ShopNest splits Catalog, Cart, Order, and Payment into services so teams can deploy catalog changes without redeploying payments.

Say this in the interview

1. Define — one clear sentence (the short answer above).
2. Example — relate it to a project like ShopNest or your real work.
3. Trade-off — when you would not use it.