by KANNAN DURAIRAJ, Domain Architect - DigitalSoftware Engineer and Architect

Software Architecture

● Introduction - Software Architecture● Forms of Architecture ● Architecture vs Design ● Architectural Patterns● Design Patterns● Diagrams● Agile + Architecture● Principles - Architecture and Design● Recap● References

Agenda

Architecture is it a Perspective? How to see things in a meaningful way?

Need for Architecture

“Where Business meets Technology”

Definition

The fundamental organization of a system embodied in its components, their relationships to each other, and to the environment, and the principles guiding its design and evolution. Usually captured as a diagram.

My Definition

A shared understanding among various team members (business, product, development, operations) about an application or a set of applications that deliver business value by building platform capabilities that are robust, flexible - open for extension, composable by nature, and can be orchestrated to produce an optimal solutions for a business and add value to the end user.

In Nutshell

Define Boundaries / Contracts / Responsibility

of Software Components

Architectural Boundaries

Imagine Success With Boundary Without Boundary

What are architectural considerations?

● Hard choices in Software● Expensive part of Development and Delivery● Important stuff! ● Business Value vs Platform Capability

current vs future

What are those hard choices?

Any thoughts?

Hard things and important stuff:

● Programming Language - Fit, Tools and Skills● Reversibility - heights of tight coupling● Building on top of unstable platform or software● Over Engineering (should be Agile, right?)● Complex frameworks and dependencies (YAGNI)● Deployment Environment, DevOps● Compliance, Security and Performance

Why Architecture is so important?

What & Why Where How Product Feature Platform Capability ImplementationUX & CX Cross-Cutting Develop & Test Customer Value Concerns Plays by Component / System boundaries

Define Boundaries

Forms of Architecture

Forms of Architecture

System ArchitectureComponent ArchitectureApplication ArchitectureData / Information ArchitectureIntegration ArchitectureIT / Network / Infrastructure ArchitectureEnterprise Architecture

Software Architects = City Planners

city keeps changing… so does software!

Architect Roles

Integration ArchitectApplication / Technical ArchitectSolution Architect / Solution DesignerDomain ArchitectEnterprise Architect Principal / Chief Architect

Software Architecture and Software Design - is it the same thing?

Which one is more important?

Both are important - one can’t survive without the other.

Let's look at the Definition of ‘Software Design’

Definition: Software Design

The fundamental organization of code/modules within a component, and its relationships to each other, and to the run time environment, and the principles guiding its development to deliver a specific goal/functionality of an overall solutions.

Usually referred to as Application or Module design.

Patterns

Patterns

In software engineering, a software design pattern is a general reusable solution to a commonly occurring problem within a given context in software design. It is not a finished design that can be transformed directly into source or machine code.

An architectural pattern is a general reusable solution to a commonly occurring problem in software architecture within a given context. Architectural patterns are similar to software design pattern but have a broader scope.

Architectural Patterns

● Service-Oriented (SOA) and Microservices● Event-Driven / MOM / ESB● Layers● Multi-Tier (2-tier, 3-tier, n-tier) / Client-Server● Model-View-Controller,

Presentation-Abstraction-Control, Model-View-Presenter, Model-View-ViewModel

Architecture Styles

Structure● Component-based, monolithic, Layered, etc

Messaging● Event Driven, Pub-Sub, Async Messaging, etc

Adaptive ● Plugin, Reflection, etc

Distributed● Client-Server, REST, SOA, Microservices, etc

Design Patterns

Creational ● Abstract Factory, Builder, Factory Method,

Singleton, PrototypeStructural

● Bridge, Adapter, Composite, Decorator, Facade, Proxy, Flyweight

Behavioral ● Command, Observer, Visitor, Chain of

Responsibility, etc..

Diagrams

Why Diagrams? ● Nothing but a form of “representation”● Simple to understand, common language● Simplifies Complexity (conceptualize)● Abstracts code/development● Logical + Data Flow + Integration View

Agile &

Architecture

Agile + Architecture

Software Architecture in Agile Development Process

● Evolutionary Architecture and Emergent Design● YAGNI● Defer until the last responsible moment● Refactoring● Spikes, Stripes and Tracers● Pragmatic

Agile Architecture

It's about “Just Enough”- Boundaries, Structure, Vision and Leadership - Understand how the significant elements fit

together- Provide the foundations and vision to move

forward- Mitigate the key risks

Agile Architecture “Guiding Principles”

● Last Responsible Moment● Continuous Integration● Lightweight, Living Documentation● Continuous Delivery● Adapt for Organizational Structure● Design for Replaceability

Architectural Patterns will evolve over time

● Microservices● API Layers

- Experience, Gateway, Application / System, Core● newServerless / FaaS● IoT, Smart Watch, Smart Cars - Tesla / Driverless● new Unikernels - Clive, MirageOS, Rump Kernels

Key Enablersa.k.a

Platform for Business

External Enablers (Industry / Market Push)

Cloud Infrastructure - Agility- Elasticity of Compute Resources

SaaS - Integration is easy, follow standards - REST, SAML

Microservices and API - deliver faster, deliver frequently

Internal Enablers

The two key enablers are:

● A high-speed culture○ A poor culture inhibits organisational changes designed to increase

speed.○ Improve decision-making processes, can’t slow down delivery

● Strategic focus - two critical elements: ○ a clear strategic goal and ○ a focused strategic agenda.

If the culture injects the fuel for speed, strategic focus delivers the grip and traction.

Recap

● Software Architecture is a shared responsibility ● Ask ‘what, why, where’ before ‘how’ ● Patterns and Principles (Architecture & Design)● Cool Diagrams!! ● Collaboration, close the feedback loop● Agility in process is only half good without

Architecture agility● Market Hypes & Internal Culture

Conclusion

Embrace by participation ● Minimum Viable Architecture / Agile Architecture● Don’t think Architecture as just● Architecture Solution is a living document just like

API documentation