Engineering principles

If it looks like a duck, quacks like a duck, but needs batteries - U have the wrong abstraction

“Give me six hours to chop down a tree and I will spend the first four sharpening the axe” – Abraham Lincoln 🪓

Reliable Software Design Principles

Separation of Concerns – distinct functionality into parts that address specific aspects.
Leads to high Cohesion and loose Coupling 🪛🛞
Modularity – break down large systems into smaller independent reusable modules 🧩
Anticipation of Change – consider future needs when designing Ur software 🛸
Maintainability – write features that’s easy to understand and modify 🚑
Scalability – adapt to increased demand without failing or excessively slowing down 🥖
Testability – design functionality in away easy to test, identify and fix bugs early 🐞
Security – design with security in mind for threats protection and reliable functioning 🕵️
Resiliency – ability to withstand or recover quickly: proactive monitoring, decentralisation, load balance, fault tolerance, graceful degradation, fast recovery 🍀️
Continuous Delivery - iterative development, frequent releases, instant rollbacks 📯

KISS

Keep
It
Simple
Stupid

Strive for clear, concise, and easy to understand & to use solutions. Avoiding unnecessary complexity will make Ur system more robust, easier to maintain & to extend

DRY

Don’t
Repeat
Yourself

Avoid constant copy-paste. Create reusable entities to reduce redundancy

YANGI

You
Are
Not
Gonna
Need
It

Don’t implement features or functionalities unless there’s a clear need for them. This reduces the system complexity and maintenance overhead

WOMBAT

Waste
Of
Money
Brains
Aand
Time

Avoid projects that drain resources without yielding the desired results

SMART

Specific
Measurable
Achievable
Relevant
Time bound

Create effective goals to increase the chances of success

SYSTEMS

Save
YourSelf
Time
Energy
Money
& Stress

”The Purpose Of a System Is What It Does” should be understandable by observing its actual behavior, rather than just its intended purpose

INVEST

Independent
Negotiable
Valuable
Estimable
Small
Testable

Ensure that tasks(stories) are clear & actionable. It’ll contribute to the overall project goals

FOCUS

Follow
One
Course
Until
Success

Approach work strategically, prioritize effectively, staying focused on achieving Ur goals

MILE

Maximum
Impact
Minimum
Effort

Maximize the impact by leveraging existing resources or via minimizing the effort required. Focus on what’s really brings value (“the vital few”)

SPACE

Satisfaction & wellbeing
Performance
Activity
Communication & collaboration
Efficiency & flow

Identify areas for improvement to create a more positive and productive work environment

TDD

Test
Driven
Development

Write the tests for functionality before the actual implementation. Write failing test. Make it pass. Refactor

SOLID

Single Responcibility principle (SRP)
“One class should have one and only one responsibility”
Open/Closed principle (OCP)
“Software entities should be opened for extension, but closed for modification”
Liskov Substituion principle (LSP)
“Objects should be replaceable with instances of their sub-types with no altering the program correctness”
Interface Segregation principle (ICP)
“Many client-specific are better than one general purpose interface”
Dependency Inversion principle (DIP)
“Depend on abstraction not on concretion”

4 Object-Oriented Programming Principles

Abstraction focusing on essential features of entity without implementation details
Encapsulation hiding the implementation details exposing only the clean interfaces
Inheritance ability of children to inherit functionality from a parent by extending it
Polymorphism ability of implementation to take multiple forms of abstraction

”Composition over Inheritance” suggests it’s better to compose objects (HAS-A) to achieve polymorphic behavior & code reuse rather than inheriting (IS-A) from a parent

Resiliency Principles

Circuit Breaker – Fail Fast, allows to perform default or fallback operations 🧯
Redundancy – if one instance fails another should take over 🧻
Backpressure – throttle incoming workload to not exceed throughput capacity 🚰
Bulkhead Pattern – failure of one shouldn’t lead to failure of entire system 🚢
Fallback – default value (or cache) to rely on in case of failure ☎️
Retry – make several attempts before failing 🛎️
Timeout – limit time until response instead of infinite waiting ⌛

Proactive monitoring & alerting are crucial for system’s Availability & fast recovery on the road to zero downtime 🟢

“Imho, regardless of the job title, whole team would benefit from knowing these principles”