2. Monolithic Architecture: Understanding the Pros, Cons & Contextual Considerations

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By Craig Worrall,

Founder and CEO

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This is the second instalment in our four-part series on software architecture. 

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When developers discuss software architecture, the monolith is often cast as an outdated or naive approach - a relic of earlier stages in software engineering. Critics cite its limitations with passion: scalability bottlenecks, difficulty deploying components independently, inflexible tech stacks. And yet, many of today’s most successful systems were built - intentionally and profitably - as monoliths. 

However,  many of the features commonly seen as flaws are, in fact, conditional. Their impact depends on the context in which the architecture is used.

At Transacumen, we gave careful consideration to these trade-offs. Our architecture - used in Stratum and across our product suite - deliberately blends monolithic and microservice traits to harness the strengths of each.

In this article, we’ll examine monolithic architecture more closely - not to refute its drawbacks, but to reframe the conversation. 

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The Nuance of Monolith Pros and Cons

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The monolith is often defined by what it isn’t. Unlike microservices, it doesn’t fragment functionality into independently deployable services. Instead, it packages the application into a single deployable unit - typically one codebase, one runtime, and one deployment pipeline.

This structure can yield several operational benefits, especially early in a product’s lifecycle:

• Simpler local development: Developers can stand up the entire application on their machine with minimal orchestration.
  
• Easier debugging and tracing: With all components in one place, there’s no need to chase down logs across distributed services.
  
• Straightforward deployment: A single pipeline, a single deploy artefact - less complexity, fewer moving parts.
  
  

But the very same features can also become pain points:

• Scaling limitations: Monoliths are harder to scale horizontally at the component level. Everything scales together - whether it needs to or not.
  
• Slower release cadence: A bug fix in one module may require redeploying the whole system, even if other components are unaffected.
  
• Technology lock-in: Choosing a tech stack up front can lead to inertia, making it costly to introduce alternative frameworks or languages later.
  
  

What’s important to note here is that none of these attributes are strictly good or bad. Their impact hinges on factors like:

• Team size and structure: Smaller teams often benefit from a unified codebase, while larger, functionally split teams may run into coordination overheads.
• Project complexity: For many internal tools or early-stage products, the simplicity of a monolith outweighs its longer-term trade-offs.‍
• Operational maturity: Teams without robust observability or service management capabilities may struggle with the overhead of distributed systems.
  
  

In other words, monoliths aren’t inherently problematic. Their value is context-dependent. And in the right environment, they can be the most effective architectural choice.

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The Inherent Traits of a Monolith

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Even as we argue for nuance, some characteristics of monolithic systems are inescapable. These aren’t subjective trade-offs - they are consequences of being a “single deployable unit.”

Let’s explore three core implications:

1. Single Unit of Deployment

By definition, a monolith is deployed as a whole. This tight coupling means that any change (no matter how isolated) requires rebuilding and redeploying the entire application. While this simplifies some aspects of release management if there’s only one thing to deploy, it can hinder agility at scale. This is often where teams need the freedom to evolve parts of the system independently.

2. Minimal OS-Level Fault Isolation

In a monolith, components share the same process space. If one component runs into memory leaks, resource contention, or uncaught exceptions, it can impact the availability of unrelated parts of the application. Unlike services deployed in separate containers or processes, there are fewer barriers between components when it comes to failure propagation.

3. Reduced Technology Diversity

Introducing multiple programming languages, runtimes, or frameworks within a single monolithic codebase is difficult. It’s not just a matter of tooling - it’s also about cohesion. Most monoliths gravitate toward a dominant tech stack, making it harder to experiment or evolve certain parts independently.

These traits aren't flaws per se, but they are constraints. And any team choosing a monolith should do so with full awareness of these constraints and a plan to manage them.

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How to Successfully Implement Monolithic Architecture

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Despite its challenges, the monolith remains not only viable but optimal in many scenarios. Its advantages - particularly around simplicity, coherence, and initial velocity - are substantial. But these advantages don’t come for free.

To realise the benefits of a monolith without being dragged down by its limitations, teams must apply deliberate design discipline:

• Invest in modular boundaries within the monolith to preserve internal separation of concerns.
• Choose technology deliberately - early language and tooling decisions shape performance, team workflow, and long-term adaptability.
• Use techniques like feature flags and gradual rollouts to reduce the risk of single artefact deployment.

Without such practices, the monolith can become brittle over time. What began as a fast-moving, developer-friendly codebase can morph into a tangled, high-risk liability.

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Why This Matters to Us at Transacumen

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At Transacumen, we don’t see the monolith as obsolete or the microservice as universally superior. Instead, we treat software architecture as a set of interdependent decisions - ones that reflect team dynamics, runtime realities, and business constraints. That philosophy underpins our design of Stratum.

Stratum draws on both monolithic and microservice concepts. It is structured to retain the developmental efficiency, internal coherence, and performance characteristics of a monolith - while adopting microservice-style separation where it meaningfully reduces risk and enables scalability and availability.

This hybrid approach emerged from real-world operational experience in critical payment systems - where neither pure monoliths nor fully distributed microservices consistently met business demands.

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Up Next: Microservices and Their Own Set of Trade-Offs

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In the next article, we’ll examine the microservices model, looking beyond the headline benefits such as independent deployability, fault isolation, and delve into the operational and organisational trade-offs that often come with it.

We’ll also introduce the architectural philosophy behind Stratum and how it navigates these trade-offs differently. In doing so, we hope to offer a compelling new path forward - one that learns from both models without being constrained by either.

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