Software architecture is the high-level design of a software system that defines its components, interactions, and properties. Software architecture evolves over time to cope with changing requirements, technologies, and challenges. In this essay, I will briefly describe some of the main phases of software architecture evolution.
One of the earliest forms of software architecture was mainframe architecture, where all the intelligence and processing was done by a central host computer and the users interacted with it through terminals. This architecture was simple and efficient for batch processing and data management applications, but had limitations in scalability, reliability, and user interface.
To overcome these limitations, two-tier architecture emerged, where the client tier handled both presentation and application logic, and communicated with a server tier that handled data access and storage. This architecture improved performance, usability, and flexibility for interactive applications such as desktop systems and web browsers. However, it also introduced problems such as network congestion, security risks, and code duplication.
To address these problems, three-tier architecture was developed, where the presentation layer was separated from the application layer on the client side, and the application layer communicated with a data layer on the server side. This architecture increased modularity, reusability, and maintainability for complex applications such as enterprise systems and e-commerce platforms. However, it also increased complexity, overhead, and coupling among layers.
To deal with these issues, service-oriented architecture (SOA) was proposed, where the application layer was decomposed into independent services that exposed their functionality through standard interfaces and protocols. This architecture enabled interoperability, scalability, and agility for distributed applications such as web services and cloud computing. However, it also required coordination, governance, and quality assurance among services.
To cope with these challenges, microservices architecture was introduced, where each service was further divided into small and autonomous units that communicated through lightweight mechanisms such as RESTful APIs and message queues. This architecture enhanced modularity, testability, and deployability for dynamic applications such as social media and streaming platforms. However, it also increased operational complexity such as monitoring, logging, tracing, fault tolerance, etc.
Closely related to microervices are micro frontends, which takes the concept further not just the service layer, but the full vertical slice are separated. Micro frontends are an architectural and organizational style where the front-end of the app is decomposed into individual, loosely coupled “micro apps” that can be built, tested, and deployed independently. This style aims to apply the benefits of microservices to the front-end development, such as modularity, autonomy, scalability, etc. Micro frontends can be implemented using various techniques such as iframes, web components, JavaScript frameworks, etc. depending on the needs and preferences of each team and project.
The next phase of software architecture evolution is likely to involve intelligent connected systems, where software components will leverage artificial intelligence (AI), internet of things (IoT), edge computing, blockchain etc. to create smart solutions for various domains such as healthcare, transportation, education, etc. This phase will pose new opportunities as well as challenges for software architects such as ethical, legal, social implications of AI and IoT systems, security and privacy of data and transactions, etc.
In conclusion, software architecture has evolved from simple monolithic structures to complex distributed systems over time to meet changing needs and expectations of users and stakeholders. Software architects need to keep up with these changes by learning new skills technologies, patterns, practices etc. to design effective solutions for current as well future problems.