Goldilocks and the Code: Not Too Big, Not Too Small—Just Right

In modern software design, one debate keeps resurfacing: monolith vs microservices. On one end, we have huge, tightly coupled applications. On the other, a sprawling network of tiny services or functions that barely do anything on their own.

This isn’t just an architectural dilemma—it’s a question of balance. And oddly enough, it reminds me of a children’s story.

Like Goldilocks choosing between bowls of porridge, beds, and chairs, software teams are faced with choosing the right size and structure for their code and systems. Let’s explore what happens when your functions, services, or systems are too big, too small, or just right.

🧱 Function Level: Monolith Thinking vs Micro-Abstraction

Too Big (Papa Bear):
A 600-line method that queries data, processes logic, and formats the UI. Impossible to test. Risky to touch. Classic monolith behavior inside a function.

Too Small (Baby Bear):
A series of 12 micro-functions that do nothing but pass arguments or return values. You follow breadcrumbs through multiple files just to find where the logic lives.

Just Right (Momma Bear):
Each function does one clear task with real purpose—like calculating tax or validating input. It’s short, focused, testable, and doesn’t delegate 100% of its responsibility.

🧠 Tip: If a function only exists to call another function, you may have created an abstraction sinkhole.

🧩 Module Level: Cohesion vs Chaos

Monolith vs microservices is often framed as an either/or. But modules—whether in a monolith or a service-based design—should be structured to follow purpose, not just scale.

Too Big: One giant module handles everything from business rules to data access. Changing anything risks unintended side effects.
Too Small: Logic is split across modules with a single method in each. Developers waste time tracking which one to use and when.
Just Right: A module encapsulates a capability (e.g., “Order Management”), with clear APIs and ownership, whether it lives in a monolith or a service.

🏗️ Application Level: Monolith vs Microservices

Here’s where the chunky vs chatty problem hits hardest.

Too Chunky (Monolith): A single deployment. One failure can bring down everything. Hard to scale independently. Slow deployments.
Too Chatty (Microsplosion): A microservice for every endpoint. High latency, difficult debugging, DevOps overload. More time spent managing the plumbing than delivering features.
Just Right (Modular Monolith or Coarse-Grained Microservices): Logical services grouped by business domain. Clear interfaces. Reasonable service granularity. Shared libraries where appropriate. Deployable independently when necessary, not because it’s trendy.

🔧 Best Practice: Use bounded contexts from Domain-Driven Design to define service boundaries. Don’t create a microservice for every noun.

🧠 Developer Experience: Cognitive Load Matters

Software isn’t written just for CPUs—it’s written for humans to read, maintain, and evolve.

Systems that are too fragmented increase cognitive load, slow debugging, and hurt onboarding.
Systems that are too tightly coupled become fragile and hard to refactor.
The sweet spot is designing for intentional clarity: small enough to be understandable, large enough to be useful.

📊 Performance and Reliability: Chattiness Comes at a Cost

In real-world production:

Chatty systems cost more in latency, tracing, retries, and monitoring
Chunky systems suffer from scaling constraints and deployment risk

⚖️ Trade-Off: Make service calls meaningful. Favor coarse-grained APIs that encapsulate workflows. Avoid calling six services to complete one customer transaction.

🧸 The Goldilocks Principle in Software Design

So what’s the takeaway?

In every layer—from functions to modules to systems—there’s a balance between size, abstraction, and cohesion. Most architectural pain comes not from choosing monolith or microservices, but from going too far in either direction.

Just like Goldilocks learned:

Some code is too big.
Some code is too fragmented.
But thoughtful, business-aligned, maintainable code is just right.

🔗 Keep Reading:

📌 Final Thought

You don’t need a microservice for every endpoint or a monolith that eats the world. What you need is clarity, cohesion, and a little common sense. And maybe a fairy tale to remind you when you’ve gone too far.