Microservice vs Monolithic Architecture
What is a microservices architecture?
A microservices architecture is an architectural style that structures an application as a collection of loosely coupled, independently deployable services. Each microservice focuses on a specific business capability, runs in its own process, and communicates with other services via well-defined APIs, often over gRPC or messaging queues like Kafka or RabbitMQ.
Key Advantages of Microservice Architecture:
- Independent Deployment
- Resilience
- Resilience
Below are a few concise, interview-ready responses explaining “Why microservices?” without simply rehashing the definition. You can tailor these scripts to your specific system design scenarios
How to justify your decision to use a microservices architecture:
- If one microservice fails (e.g., payment processing is down), the rest of the system can continue functioning (users can still browse products, receive notifications, etc.). This containment of failures improves overall uptime and user experience.
- One of the primary reasons I’d choose microservices is that each service can be scaled independently. For instance, if user requests spike in the checkout process but remain normal elsewhere, we can allocate more resources just to the checkout service without over-provisioning the entire application.
- Microservices break large, monolithic releases into smaller, independently deployable units, reducing time-to-market for new features. Each team can manage its own service, choose appropriate tech stacks, and release on its own schedule, no need to coordinate a massive, all-or-nothing rollout.
- Microservices fit well when the product naturally breaks down into distinct domains, such as: search, payments, profiling, notifications, and that have different scaling and security needs. Each domain can evolve independently, aligning tech and business logic more closely.
Example Interview Soundbite
Candidate:
What is Monolithic Architecture?
A monolithic architecture is one in which all components of an application are combined into a single, cohesive unit. This typically means a unified codebase with a single build and deployment process. All features, such as user authentication, business logic, and database operations, are bundled and deployed together.
How to justify your decision to use a Monolithic Architecture
Below are a few concise, interview-ready responses explaining “Why a monolithic architecture?”. You can tailor these scripts to your specific system design scenarios:
- A single database schema often suffices for monolithic apps, which can simplify queries, transactions, and data migrations, especially if your use cases are not excessively large or complex.
- Maintaining a monolith is generally more straightforward instrumentation and monitoring are simpler to set up. Plus, you don’t have to manage distributed tracing, versioned APIs, or consistent message formats across multiple services.
- By deploying a single artifact, you potentially lower the overhead on infrastructure, no multiple containers or services to run. This can be significant for early-stage projects with modest budgets.
- With everything in one place, you can run unit tests, integration tests, and end-to-end tests against a single codebase. This reduces the complexity that comes with inter-service communication in microservices.
Example Interview Soundbite
Candidate: