Why Understanding Software Architecture Evolution Matters for Developers

If a software developer does not understand the evolution of software architecture, it limits technology selection, career growth, and promotion opportunities. This article lists the four main software architectures and their pros and cons to broaden developers' knowledge.

1. Monolithic Architecture

Monolithic architecture is a basic three-tier model: front‑end (Web/mobile) + business logic layer + database layer. It is typical of Java Spring MVC or Python Django applications. Its diagram is shown below:

While easy to deploy and test initially, monolithic applications become cumbersome as codebases grow, leading to high complexity, accumulating technical debt, low deployment frequency, poor reliability, limited scalability, and hindered technological innovation.

2. Distributed Application

Distributed applications extend monolithic systems by splitting them into multiple business modules deployed on separate servers, with distributed middle‑tier and databases (e.g., Redis, Elasticsearch). Load balancers like LVS/Nginx distribute requests. Diagram:

Advantages include reduced coupling, clear responsibilities, easy expansion, flexible deployment, and improved code reuse. The main drawback is the increased effort required for remote interface development.

3. Microservice Architecture

Microservice architecture decomposes the system into many small services that can be deployed on different servers or containers. Failures in one service do not affect others. Common frameworks are Spring Cloud and Dubbo. Diagram:

Benefits: easier development and maintenance, fast startup, localized deployment of changes, and freedom to choose technology stacks per service. Challenges: higher operational demands, inherent distributed‑system complexity, costly API adjustments, and potential duplicate work across services.

4. Serverless Architecture

Serverless computing abstracts away server management, allocating resources on demand. Notable services include AWS Lambda, Google Firebase, and the now‑defunct Parse. Diagram:

Advantages: low operational cost through pay‑as‑you‑go billing, simplified infrastructure maintenance, improved maintainability via third‑party services, and faster development speed using BaaS components. Disadvantages: vendor lock‑in, limited successful large‑scale cases, and lack of industry standards. Currently, microservice architecture is the mainstream among the four models, and serverless is expected to become a significant future trend.