SOLID Principles: Designing Clean and Maintainable Code — PickAClass
4.0 (6) ⏱ 2h 30m 📚 25 lessons 🎧 Audio version

SOLID Principles: Designing Clean and Maintainable Code

Learn how to apply the five core SOLID principles to write robust, scalable, and easily testable object-oriented code in languages like Java, C#, and Python.

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About this course

Writing code that works is only the first step; writing code that remains easy to maintain, extend, and test as your application grows is what defines a professional developer. This text-based course guides you through the foundational concepts of software architecture, helping you transition from writing fragile, tightly coupled code to structuring elegant, modular systems. By studying these core design patterns, you will learn how to prevent common software rot and build systems that adapt effortlessly to changing requirements. Through clear explanations and practical code examples, you will gain the confidence to make smart architectural decisions in any object-oriented language. What you'll learn: - Understand the core terminology and foundational concepts of object-oriented design before diving into advanced architectures. - Apply the Single Responsibility Principle to create focused, modular classes that are easy to maintain. - Design open-closed systems that allow you to add new features without modifying existing, tested code. - Implement Liskov Substitution and Interface Segregation to build reliable, flexible inheritance hierarchies. - Master Dependency Inversion to decouple high-level logic from low-level details using modern dependency injection patterns. - Practice refactoring rigid code structures into clean architectures that facilitate automated testing. You will begin by exploring fundamental design concepts, then progress through detailed, text-based explanations and code walkthroughs for each of the five SOLID principles. This course is designed for beginner programmers and software developers who want to improve their code quality, with no prior architectural experience required. Start writing clean, professional software today.

What you'll get

  • 📜 Certificate of completion
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  • 💬 Personal AI tutor
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  • 🎧 Audio version included
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  • 📱 Phone or computer
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  • 💸 14-day refund
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  • Short & focused
    2h 30m of practical content

Certificate of completion

Every course you complete on PickAClass issues a credential like this — original, with its own code, verifiable by URL, and detailed about what was actually demonstrated.

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PickAClass
Skills profile · verifiable
Document
Certificate of Mastery
This certifies that
Name Surname
has successfully demonstrated mastery of
SOLID Principles: Designing Clean and Maintainable Code
Skills demonstrated
Behavioral pattern analysis
Foundational
1.2 hrs
Decision-architecture frameworks
Proficient
1.4 hrs
A/B test design
Proficient
1.7 hrs
Behavioral copywriting
Advanced
1.9 hrs
P
PickAClass — Name Surname
SOLID Principles: Designing Clean and Maintainable Code
Page 2 of 2
Performance detail
Coursework summary
Lessons completed 14 / 14
Practice questions 26 / 28
Assignments submitted 4 (avg 4.5 / 5)
Capstone project Reviewed — 4.6 / 5
Total practice 6.2 hrs
Performance benchmark
Cohort rank Top 12% of 1,625
Time to completion 11 days (median: 22)
Mastery score 91 / 100
Practice-question score 94%
Skill verification Verified Skill Path
Verify this credential
pickaclass.com/certificates/PCC-2026-X4F7-AP19
Issued under the academic standards of PickAClass. Skill levels reflect assessed performance against the course's competency rubric. This is an original credential of this platform.

Reviews (6)

محمد بن علي EG Verified learner
★ 4 · July 26, 2026

Solid content and presented clearly. I appreciated the real-world applications shown. Could have used a few more practice opportunities.

Phạm Thị Dung VN
★ 5 · July 16, 2026

This is exactly what I was looking for. Loved the practical examples, they really helped solidify the concepts.

佐藤 陽子 JP Verified learner
★ 4 · June 21, 2026

Pretty good overall. The structure was logical, and many of the examples were helpful. A few areas could have used a bit more depth, but it's solid.

مريم بنت سلطان الطائي OM
★ 4 · June 14, 2026

A good introduction. The structure was mostly clear, but I wish there were a few more real-world examples. Still, learned a lot.

Siobhan Lynch IE
★ 4 · June 7, 2026

Really enjoyed the flow of this. The practical applications discussed were spot on. Great course!

Gabriela Mora CR Verified learner
★ 3 · June 7, 2026

Good foundational course. Explained things clearly, but could have used more hands-on practice to solidify the learning.

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Just a phone or computer with internet. No installs, no special hardware.

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Forever. Once you purchase, the course is yours to revisit anytime.

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Yes. On completion you'll receive a certificate you can add to your LinkedIn profile.

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