Microservices vs Monolithic Architecture for System Design Interview

image_credit - DesignGuru

Hello friends, if you are preparing for a System design interview, then you must have come across questions on Microservices architecture.

In the last few articles, I have answered popular System design questions like API Gateway vs Load Balancer and Horizontal vs Vertical Scaling, Forward proxy vs reverse proxy, and today, I will answer another interesting System design question, *"difference between monolith and Micro service architecture?".

With the growing popularity of Microservices, I am seeing more and more questions from Microservices on System Design Interviews, and this is one of the starter questions.

In system design interviews, understanding the difference between microservices and monolithic applications is crucial. While monolithic architectures offer simplicity and ease of development, microservices provide scalability, flexibility, and resilience through their distributed nature and modular design.

For example, in the case of monolith architecture, your entire application is packaged and deployed together, while in the case of Microservices architecture, an application is broken into a collection of small, independent services that communicate with each other over a network, mostly over HTTP.**

Each service is responsible for a specific business capability and can be developed, deployed, and scaled independently. This makes it easier to make changes to the application without affecting other parts of the system.

Microservices also enable applications to be developed and deployed faster, and they are better suited to large and complex applications where different parts of the application may need to evolve at different speeds.

By the way, Microservices are not a silver bullet, there are debugging and troubleshooting issues with Microservices because application log files are scattered across multiple services.

Also, for a latency-sensitive application, Microservices is not a good choice because it increases latency.

Now that we are familiar with the basic idea of Microservices and Monolithic architecture, it's time to dive deep and see the pros and cons of both software architectures.

By the way, if you are in a hurry, then the diagram from DesignGurus.io, one of the best resources for system design interviews and creator of Grokking the System Design Interview nicely explains it; he even added a comparison to serverless architecture:

And, if you are preparing for a System design interview, along with Design Guru, Educative, ByteByteGo, and Exponent are great resources to further improve your preparation.

Difference between Monolithic vs Microservices Architecture

Now that you have a basic idea of what Microservices offer in terms of Monolithic applications, it makes sense to deep dive and find out more technical differences between these two architecture style to build software applications.

Here are the key differences, advantages, and disadvantages of Monolithic and Microservices architecture:

1. Deployment and Management

Monolithic applications are simple to deploy and manage, since all components are included in a single package, but Microservices are complex to deploy and manage, since each service is deployed independently and must communicate with other services over a network.

Microservice architecture also have increased operational overhead, as each service must be deployed, monitored, and managed individually.

2. Easy to Understand

In the case of Monolithic architecture its easy to understand the entire system, since all components are integrated tightly, while its difficult to understand the flow in Microservices because of multiple services.

3. Debugging

Monolithic applications are easier to debug as compared to Microservices because the entire application runs in a single process, while Debugging can be more difficult in Microservice architecture, since issues can span multiple services.

For example, if data is updated in one service it can have origin in some other service like authentication or authorization

4. Development

Microservices promote flexible development and are better suited to large and complex applications where different parts of the application may need to evolve at different speeds.

While Microservices are better suited for small, latency sensitive application. In short, Microservices enable faster development and deployment, since services can be developed and deployed independently.

5. Coupling

In the case of Monolithic architecture, components are tightly coupled, which makes it difficult to make changes to the application without causing unintended consequences, while microservices promote low coupling.

It's also easier to make changes to the application, since each service is responsible for a specific business capability.

6. Maintainence

Monolithic applications are easier to start but difficult to maintain. As the application grows, the code base becomes larger and more complex, making it harder to maintain.

On the other hand, Microservices are easier to maintain as you can make changes in one service without deploying other services.

7. Performance and Scalability

Microservice architecture allows for better scalability and performance improvement, since each service can be scaled independently, while performance bottlenecks can easily happen in a monolithic application, since all components share the same resources.

In short, while monolithic architectures offer simplicity and ease of development, microservices provide scalability, flexibility, and resilience through their distributed nature and modular design. So both have their places.

And, here is also a nice diagram to highlight the difference between API Gateway and Load Balancer from ByteByteGo, one of the best places to prepare for System design interviews

That's all about difference between Microservices and monolithic architecture and applications. As I said, monolithic architecture is simpler and easier to deploy and manage, but is less flexible and harder to change. Microservices architecture is more flexible and easier to change, but is more complex and harder to deploy and manage.

While Microservices is latest trend in Software development, and a well-designed microservices architecture can provide benefits such as scalability and faster development, especially on the cloud, it requires a more complex deployment and management infrastructure.

On the other hand, a well-designed monolithic architecture can provide benefits such as simpler deployment and easier debugging, but can become more difficult to change as the application grows.

This is a really useful concept for System design interviews, especially Microservice architecture, and you shouldn't miss out on that. For better preparation, I also suggest checking out sites like DesignGurus, Educative, ByteByteGo, and Exponent, all of which are great resources for tech interview preparation, particularly System design.

Forward Proxy vs Reverse Proxy in System design

Disclosure: This post includes affiliate links; I may receive compensation if you purchase products or services from the different links provided in this article.

image_credit - DesignGurus.io

Hello folks, in last few article, I was answering popular System design questions like API Gateway vs Load Balancer and Horizontal vs Vertical Scaling, and today, we are going to take a look at another interesting System design question, Reverse Proxy vs Forward Proxy.

These questions are different than system design problems like how to design WhatsApp and YouTube but they are equally important and if you have knowledge of them you can mention in most of the system design problems.

Now coming back to the topic, In network architecture world, proxies play a pivotal role in managing and securing communication between clients and servers.

There are two common types of proxies, forward and reverse proxies, they serve distinct purposes and operate at different layers of the networking stack. Forward proxies are used to shield clients from external networks while Reverse proxy acts as a frontend Facade for backend Servers, much like API Gatewawy and load balancers.

Let's go deep into the intricacies of forward and reverse proxies to know their differences and understand their respective roles in system design.

By the way, if you are in hurry then below diagram from DesignGuru.io, one of the best resource for system design interviews and creator of Grokking the System Design Interview nicely explain it:

What is Forward Proxy?

A forward proxy, also known as an outbound proxy, acts as an intermediary between clients and external servers, intercepting outbound requests from clients and forwarding them to their intended destinations.

Here is what forward proxies do for you:

Client-Side Proxying
Forward proxies are typically deployed on the client side of a network, serving as a gateway for outbound traffic. Clients configure their network settings to route traffic through the forward proxy, which then forwards requests to external servers on behalf of the clients.
Anonymity and Privacy
Forward proxies can enhance user privacy and anonymity by masking the IP addresses of clients. External servers only see the IP address of the forward proxy, making it difficult to trace the origin of requests back to individual clients.
Content Filtering and Caching
Forward proxies can implement content filtering policies to restrict access to certain websites or content categories based on predefined rules. Additionally, they can cache frequently accessed content, reducing bandwidth usage and improving performance for subsequent requests.
Security and Access Control
Forward proxies can also enforce security policies and access controls, allowing organizations to regulate access to external resources, block malicious websites, and inspect outbound traffic for threats or policy violations.

You can see in the diagram below that the forward proxy routes user requests to back-end servers

By the way, if you are preparing for System design interviews and want to learn System Design in depth then you can also checkout sites like ByteByteGo, Design Guru, Exponent, Educative, Codemia.io, bugfree.ai and Udemy which have many great System design courses

Now that we know what a forward proxy is let's take a look at a reverse proxy and what services it provides:

What is a Reverse Proxy?

A reverse proxy, also known as an inbound proxy, operates on the server side of a network, serving as a front-end facade for backend servers.

It intercepts incoming requests from clients and forwards them to the appropriate back-end servers based on predefined rules.

Key aspects of reverse proxies include:

Server-Side Proxying
Reverse proxies are deployed on the server side of a network, typically in front of backend web servers or application servers. They accept incoming requests from clients on behalf of backend servers and forward them internally.
Load Balancing and Traffic Distribution
Reverse proxies can distribute incoming traffic across multiple backend servers to improve scalability, reliability, and performance. They use algorithms such as round-robin, least connections, or weighted distribution to evenly distribute requests.
SSL Termination and Encryption
Reverse proxies can handle SSL/TLS termination, offloading the encryption and decryption process from backend servers. This simplifies management of SSL certificates and improves performance by reducing the computational overhead on backend servers.
Content Delivery and Optimization
Reverse proxies can cache static content, compress data, and optimize delivery to clients, reducing latency and bandwidth usage. They can also perform content rewriting or transformation to adapt content for different client devices or browsers.

Here is also a nice diagram which shows how reverse proxy work which is quite useful for system design interview, and if you are preparing for one, Educative.io's Modern System Design Guide is another awesome resource I recommend.

Difference between Forward and Reverse Proxies and Use Cases

While both forward and reverse proxies act as intermediaries in network communication, their primary objectives and deployment scenarios differ:

For example, Forward proxy is primarily used to shield clients from external networks, enhance privacy and security, and enforce access controls and it's ideal for individual users, organizations, or networks requiring outbound traffic management and anonymity.

On the other hand, Reverse Proxy is primarily used to front-end backend servers, improve scalability and performance, and provide centralized management of incoming traffic.

It is ideal for web servers, application servers, or microservices architectures requiring load balancing, SSL termination, and content optimization.

And, here is a nice diagram which highlights the difference between Forward Proxy and Reverse Proxy from ByteByteGo, one of the best places to learn System Design for interviews. If you are preparing for a system design interview, you should definitely check it out. They also have an awesome YouTube channel.

Conclusion

In conclusion, both forward and reverse proxies are indispensable components in modern network architectures, each serving unique purposes and offering distinct capabilities.

While forward proxies focus on client-side traffic management and security, reverse proxies excel at server-side load balancing, scalability, and optimization.

Understanding their differences is essential for designing resilient, efficient, and secure systems that meet the diverse needs of modern applications and services.

And, if you are preparing for a system design interview, then you may also like my previous articles

Thank you !!

Difference between API Gateway vs Load Balancer in Software Design / Microservices Architecture

Disclosure: This post includes affiliate links; I may receive compensation if you purchase products or services from the different links provided in this article.
image_credit - DesignGurus ,

Hello folks, if you are preparing for System design interviews then you must have come across popular questions like difference between API Gateway vs Load Balancer, horizontal scalability vs vertical scaling, and Reverse Proxy vs Forward Proxy.

Earlier, I have shared popular System design interview problems and in this article, I will answer the first question so that you not only can answer this question on interviews but also learn this important concept well.

In the web services world and network infrastructure, two crucial components often come into play: API gateways and load balancers.

While they both play critical roles in managing and optimizing traffic flow, they serve distinct purposes and operate at different layers of the technology stack.

Understanding the difference between these two components is not just important for System design interview but also essential for designing robust and scalable architectures. Let's delve into the nuances of API gateways and load balancers to demystify their differences.

But, let's first see what is API Gateway?

Btw, here is also a nice diagram from DesignGurus ,, one of the best place to prepare for system design interviews. This diagram highlights the key difference between API Gateway and Load balancer

By the way, If you are preparing for System design interviews and want to learn System Design in depth then you can also checkout sites like ByteByteGo, DesignGurus , Exponent, Educative , bugfree.ai and Udemy which have many great System design courses.

What is API Gateway? How does it work?

An API gateway acts as a middleware component that sits between clients and backend services, providing a centralized entry point for accessing various endpoints and functionalities.

Its primary function is to facilitate communication, security, and management of APIs. Here are key aspects of API gateways:

API Management
API gateways offer features for managing APIs, including authentication, authorization, rate limiting, and caching. They serve as a control point for enforcing security policies and access control measures.
Protocol Transformation
API gateways can handle protocol translation, allowing clients to communicate with backend services using different protocols or message formats. This capability enhances interoperability in heterogeneous environments.
Routing and Versioning
With an API gateway, requests can be routed to the appropriate backend service based on predefined rules and configurations.

Additionally, versioning support enables the coexistence of multiple API versions, ensuring backward compatibility and smooth migrations.

Analytics and Monitoring API gateways provide insights into API usage, performance metrics, and error tracking. This visibility enables operators to monitor the health of APIs, identify bottlenecks, and optimize resource utilization.

Here is a nice diagram of how API Gateway looks like:

What is Load Balancer? How it works?

A load balancer acts as a traffic distributor, evenly distributing incoming requests across multiple backend servers or instances to optimize resource utilization, improve availability, and enhance performance. Here are key aspects of load balancers:

Traffic Distribution
Load balancers distribute incoming traffic across multiple backend servers or instances based on predefined algorithms such as round-robin, least connections, or weighted distribution. This ensures efficient utilization of resources and prevents overloading of individual servers.
High Availability
Load balancers enhance the availability of services by intelligently routing traffic away from unhealthy or overloaded servers. They perform health checks to monitor the status of backend instances and dynamically adjust traffic routing accordingly.
Session Persistence
In scenarios where maintaining session state is crucial, load balancers support session persistence or sticky sessions, ensuring that subsequent requests from the same client are directed to the same backend server. This ensures consistency and avoids session-related issues.
SSL Termination
Load balancers can offload SSL/TLS encryption and decryption, relieving backend servers from the computational overhead associated with SSL processing. This improves performance and simplifies management of SSL certificates.

Here is how a load balancer look like and how it works:

Difference between API Gateway and Load Balancer?

While API gateways and load balancers share some similarities in terms of traffic management, their primary objectives and functionalities differ:

API Gateway: Focuses on API management, security, protocol transformation, and analytics. Ideal for exposing and managing APIs to external clients, enforcing access control policies, and providing a unified interface for diverse backend services.
Load Balancer: Primarily concerned with traffic distribution, high availability, and scalability. Suitable for distributing incoming traffic across multiple backend servers or instances to improve performance, reliability, and fault tolerance.

Here is also a nice diagram to highlight the difference between API Gateway and Load Balancer from ByteByteGo, one of the best place to prepare for System design interviews

System Design Interview Preparation Resources

If you are preparing for System design interviews and want to learn System Design in depth then you can also checkout sites like ByteByteGo, DesignGurus , Exponent, Educative , bugfree.ai and Udemy which have many great System design courses.

And, If you need free system design courses you can also see this article which is full of free system design courses

Conclusion

In summary, both API gateways and load balancers are fundamental components in modern network architectures, each serving distinct purposes and offering unique capabilities.

While API gateways specialize in API management and security, load balancers excel at distributing traffic for improved availability and scalability.

Understanding their differences is essential for designing resilient and efficient systems that meet the evolving demands of modern applications and services.