Is Your Development Team's Code SOLID?

The Real Foundation of Delivery

Where Code Quality Breaks Down

We've all encountered code that technically "works" but becomes a nightmare to maintain. The warning signs are unmistakable:

• Cryptic variable names like i and j that cost hours in debugging sessions. When developers can't understand what variables represent, simple changes become complex investigations.

• Overly long functions that are hundreds of lines, trying to handle five different responsibilities at once. These behemoths are impossible to test, difficult to debug, and terrifying to modify.

• Fragile modules that collapse every time a small business rule changes. One tiny adjustment cascades into system-wide failures because everything is tightly coupled.

This is where SOLID principles save teams from maintenance nightmares and delivery bottlenecks.

SOLID in Action: NetSuite Examples

Let's break down each principle with real-world NetSuite scenarios that every development team encounters:

S — Single Responsibility Principle

The Problem: A Map/Reduce script that imports vendor bills also handles approval logic, making it difficult to modify either function independently.

The Solution: Split it out—one module for import, another for workflow. This makes changes more predictable and reduces the risk of breaking unrelated functionality.

O — Open/Closed Principle

The Problem: Hardcoding payment methods in a Suitelet means every new payment option requires modifying existing code.



The Solution: Use a config object or strategy pattern. When PayPal (or any new method) comes in, you extend instead of rewriting.

L — Liskov Substitution Principle

The Problem: Different payment processors behave so differently that swapping them breaks the system.

The Solution: A PaymentProcessor base class should let ACHProcessor and CheckProcessor swap in seamlessly. If not, you've introduced hidden dependencies.

I — Interface Segregation Principle

The Problem: Services are forced to implement functionality they don't actually need.

The Solution: Don't force a CustomerSyncService to handle both syncing and reporting. Separate them—CustomerSync vs CustomerReport—so consumers only implement what they need.

D — Dependency Inversion Principle

The Problem: Direct dependencies on specific implementations make code impossible to test and difficult to change.

The Solution: A Suitelet shouldn't depend directly on N/record. Depend on an abstraction like CustomerRepository. In tests, swap it out for a mock. This is also where Clean Architecture fits in (worth a post of its own).

Without SOLID principles, changes create friction, accumulating technical debt and degrading team velocity. With them, your system grows safely, allowing confident delivery, predictable changes, straightforward testing, and natural feature development.

What Leaders Can Do About It

For business leaders, SOLID isn't just "developer preference"—it's a strategic investment in delivery capability. Teams that code with discipline can respond to business needs with agility and confidence.

Here's how you can support code quality initiatives:



• Enforce readability standards - Clean names, concise functions, and consistent patterns make code maintainable by any team member.
• Apply SOLID in SuiteScript - Map/Reduce scripts, RESTlets, and client scripts all benefit from these architectural principles.
• Promote unit testing - Good design makes testing easier, and testing enforces good design—creating a virtuous cycle of quality.
• Invest in mentorship - Principles stick when senior developers actively coach through code reviews and pair programming.
• Measure quality, not just velocity - Track maintainability metrics alongside ticket counts to ensure sustainable development speed.

Building a Foundation That Lasts

Implementing SOLID principles requires more than good intentions—it takes systematic change and proven development practices. The most successful NetSuite implementations aren't just functional today, they're built to evolve gracefully as your business grows and changes.

At ATSOURCE, we help development teams adopt practices that create lasting value. Ready to strengthen your development foundation? Let's discuss how SOLID principles and expert mentorship can transform your team's delivery capability and code quality.