Monolith vs Microservices: What Nobody Tells You

Your no-BS weekly brief on software engineering.
Join 100,000+ developers

For years, developers have been told that microservices are the only way to scale. Want to build a serious application? You better start breaking things into services—user auth here, payments there, notifications over in another repo. It’s what Google, Netflix, and Amazon do, right?

But imagine this: A small startup, eager to prove its technical prowess, scrambles to split its once-cohesive codebase into a myriad of microservices. Instead of gaining agility, the team finds itself entangled in inter-service dependencies, confusing deployments, and skyrocketing maintenance costs. This isn’t a rare cautionary tale—it’s a wake-up call.

A Quick Reality Check: Microservices vs. Distributed Architecture

A monolith and microservices are just two points on a spectrum of architectural choices. Often overlooked is the fact that you don’t need microservices simply because you’ve separated your frontend and backend.

Monolithic architecture can serve a separate frontend via an API just as effectively.
Distributed architecture is an umbrella term that includes microservices, as well as SOA (service-oriented architecture), modular monoliths, and even simple backend APIs with multiple clients.
Microservices are merely one type of distributed system—and they introduce more complexity than many alternative models.

So, what’s the real question? It isn’t about choosing Monolith vs. Microservices—it’s about determining whether you need a distributed system at all.

Microservices Aren’t a Graduation—They’re a Tradeoff

It’s common to view microservices as a natural progression—a technical graduation. But unlike moving from high school to college, there’s no inherent benefit to “upgrading” to microservices.

Before diving in, ask yourself:
Do microservices truly align with your needs?

For many startups or small teams, microservices can create fragmentation instead of streamlining operations. As one industry expert, Eileen Uchitelle, noted in her Rails World talk:

Often organizations will start looking into microservices in order to get the experience of building a Greenfield application and move away from the monolith.

At the same time, we recognize that for teams already on the microservices path, there are real benefits—provided you have clear ownership, strong coordination, and mature operational processes in place. It’s all about ensuring that your organizational structure is truly prepared for the tradeoffs.

The Hidden Trade: Complexity Can Slow You Down

Here’s what they don’t tell you: your code will reflect your organization’s structure (Conway’s Law).

Large companies with dozens of teams might benefit from breaking things into microservices, allowing each group to work independently.
For small teams or startups, introducing microservices may simply erect unnecessary boundaries—silos that hamper collaboration and slow progress.

This complexity isn’t just theoretical—it has tangible consequences:

Multi-Step Deployments: Instead of a simple push, you now face a choreographed dance of service updates.
Challenging Debugging: Rather than a single stack trace, you must navigate a labyrinth of service calls.
Dev Environment Nightmares: Local development can devolve into managing Docker containers, API endpoints, and inter-service communication.

If you’re wondering when microservices might be appropriate, consider these technical red flags:

Code Entanglement: Over 50% of your code touches on a core concern (like user authentication).
Database Bloat: A single table ballooning with over 1,000 columns.
Monolithic Domain Objects: When a domain object grows unwieldy and difficult to maintain.

Before deciding on a full microservices architecture, ask yourself: Is the added complexity justified by your current needs?

Bridging the Gap: Consider the Modular Monolith

Not ready to dive headfirst into microservices? A modular monolith might seem like an attractive shortcut—offering some of the benefits of microservices without the full operational overhead. This approach organizes your code into clearly defined modules while maintaining a single codebase and deployment process. It provides:

Easier Maintenance: Logical separation of concerns without the complexity of inter-service communication.

A Path Forward: A stepping stone that lets your team gradually adopt more modular structures if the need arises.

However, a modular monolith isn’t a silver bullet. In fact, it may even be counterproductive if the underlying organizational challenges aren’t addressed. By relying on increased collaboration and coordination, it can lead to slower overall throughput if the team’s communication or processes are already strained. In other words, while it may reduce technical overhead, it doesn’t eliminate—and can even exacerbate—the need for robust, well-aligned teamwork.

Remember, the goal isn’t to adopt the latest trend, but to make a choice that fits your team and challenges.

Microservices Demand More Than Just Code—They Require Engineering Discipline

Adopting microservices shifts the challenge from system design to maintaining stability across a distributed landscape. To succeed, your organization must be prepared for:

Clear Team Boundaries and Ownership: Without well-defined responsibilities, service fragmentation can create chaos.
Robust DevOps & SRE Practices: Monitoring, logging, deployment pipelines, and service discovery must all be rock solid.
A Culture of Documentation and Coordination: Without disciplined API design and coordination, microservices can lead to increased operational friction.

If your team isn’t ready on these fronts, refining your monolith might be the smarter choice.

Should I Make the Trade?

In the end, you don’t need microservices—you need clarity about whether your challenges are truly technical or just a matter of assuming that microservices are the “next step.”

Instead of asking, “Should we use microservices?” consider:

✔ Are our teams structured for it?

Microservices thrive in organizations where teams can operate independently. If your developers frequently step on each other’s toes, adding more services won’t magically fix coordination issues.

✔ Do we have clear ownership and coordination?

Microservices introduce the challenge of distributed ownership. If your teams already struggle with unclear responsibilities in a monolith, breaking things apart will amplify these problems rather than solve them.

✔ Can we manage the added operational complexity?

Observability, deployments, inter-service communication, and debugging all become more difficult in a microservices architecture. If your team isn’t already strong in DevOps, monitoring, and automation, a premature transition could lead to more downtime, bottlenecks, and frustration.

A Smarter Path

If any of these answers is no, you’re likely better off refining your monolith first. Techniques like modularization, bounded contexts, and API layering can help you achieve many of the same benefits of microservices without the complexity. Start by fixing the pain points in your monolith before assuming microservices are the only answer.

Key Takeaways

Stick with a Monolith: When your team is small, your codebase is manageable, and your operational processes are simpler.
Adopt Microservices When:
- Your organization has clear team boundaries.
- You have robust DevOps and SRE support.
- The benefits outweigh the operational and complexity costs.
Bridge the Gap: Consider a modular monolith as a stepping stone if you’re unsure about committing to full microservices.
Be Cautious of Trends: Microservices may seem like a promotion, but they come with a high total cost of ownership (TCO) and potential pitfalls if not fully prepared.