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Software Architect

Software architect

Goals

  • Fast
  • Secure
  • Reliable
  • Easy to maintain

Mindset

  • Understand the business
  • Define the system's Goals
  • Work for client's client
  • Talk to the right people with the right language.

Process

Understand the system requirements

  • What the system should do
  • Right after setting the goal. The goal is the most important thing to archive.
  • Bussiness flow...

Understand none functional requirements

What the system should be deal with

  • Performance
    • Latency - time to finish a task
    • Throughput - number of tasks in a period of time
  • Load
  • Data volume
  • Concurrent users
  • SLA - Service Level Agreement

Quality

  • Scalability
  • Managebilaty
    • System should report the problems.
  • Modularity
  • Extensibility
  • Testability

--- Never start working on a system before setting requirements ---

Map the components

  • Web app
  • Web API
  • Mobile app
  • Desktop app
  • Console app
  • Services

Select the right technology

Considerations

  • Can the technology solve the problem?
  • Is the technology mature?
  • Is the technology popular?
  • Is the technology easy to maintain?

Backend

Frontend

Database

NoSQL vs SQL

Design the system

Components architecture

Layers

Loosely coupled components, each one responsible for a specific task. Exception handling.

  • User interface
    • Json handling
    • Authentication
  • Business logic
    • Validation
    • Enrichment
    • Computation
  • Data access
    • Database
    • File system
    • External services
Interfaces
DI - Dependency Injection
SOLID
Naming conventions
Exception handling
  • Don't try catch for just for logging.
  • Catch only specific exceptions.
  • try catch smallest block of code.
Logging
  • Track errors
  • Gather data
    • Performance
    • Which modules is most visited
    • User's flow
Caching
Security

Design patterns

Read the book

  • Factory
  • Repository
  • Facade

Write architecture document

  • Write in plain English as simple as possible. Draw diagram if needed.

Document structure

  • Background

    • Business POV: system, role, reason to change, expected impacts.
    • Why? validate your point of view, make sure you are on the same page with the client.

  • Requirements

    • Functional (no more than 5, no more thans 3 lines each)

      Short and consice is enough.

    • Non-functional

      Extrimely accurate & specific

  • Executive summary

    Focus on reader languages. Use chart or diagram. Write after all other sections are done.

  • Architecture overview

    • General description: type, major requirement.
    • High level diagram

      Logic diagram only, don't mix with physical hw.

    • Walkthrough

      How the system works, how the components interact with each other.

  • Components

    Most important

    • Role
    • Technology stack
    • Components architecture
      • Describe API: include method name
      • Describe layers: SOLID
    • Development instructions

Implement the system

Design patterns

Singleton

A class that can have only one instance. Provide a global point of access to the instance.

Why?

  • Lazy loading
  • Only need one instance

Factory

DI - Dependency Injection

Repository

Module không liên quan đến datastore không cần care về cách lấy dữ liệu.

Facade

Chia thành layer để abstract sự phức tạp phía dưới.

Command

All the information needed to perform an action is encapsulated in a command object.

The invoker has now idea what the command does. Just execute it.

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