How to Build a Project: Microservices vs Monolith

When starting a new software project, one of the key architectural decisions is whether to go with a monolithic architecture or break things down into microservices.

Each approach has its pros and cons, and the right choice depends on factors like team size, scalability needs, and how fast you want to ship features. But before we dive into comparing them, let’s take a step back and understand how software is generally built.

The Software Development Lifecycle (SDLC) – Waterfall Model

Building a software product is like constructing a building. It goes through several stages. Here’s how a traditional Waterfall Model works:

1. Requirements – Collected by Product Managers or Designers

2. Design – Senior Engineers or Engineering Managers create High-Level Design (HLD) and Low-Level Design (LLD)

3. Development – Developers (SDE1/SDE2/Interns) write the actual code

4. Testing – QA Engineers or SDETs test the product manually or through automation

5. Deployment – DevOps engineers deploy the app to production

6. Maintenance – Whenever a new feature is added, the same cycle repeats

In smaller teams, developers may also handle testing and deployment themselves.

What is a Monolithic Architecture?

A monolith is a single unified codebase that contains everything – frontend, backend, authentication, notifications, and more. All parts of the app are tightly connected and live in the same repository.

Example:

Imagine an app where the user interface, backend APIs, payment logic, and email notifications all live together in one big project folder.

What is a Microservices Architecture?

In contrast, microservices break down a big application into smaller, independent services. Each service is responsible for a specific task and can be developed, tested, deployed, and scaled independently.

Example:

A company like Uber might have:

• One microservice for fare calculation

• Another for ride tracking

• A separate one for handling payments

• And yet another for sending notifications

Each service is maintained by a separate team and may even use a different programming language.

When to Use What?

Startups or Early-Stage Projects

If you’re just starting out, a monolith can be a better choice:

• It’s faster to build and ship features

• Lower infrastructure cost

• Easier to manage with a small team

Once your product starts scaling and your team grows, you might face performance or maintainability issues. That’s when you can start breaking it down into microservices.

Larger Systems or Growing Companies

For companies like Uber, Google, or Amazon - scalability, reliability, and team independence are critical. Microservices allow

• Better fault isolation

• Easier scalability

• Faster deployments

• Technology flexibility across teams

But keep in mind—microservices also introduce challenges like:

• Complex deployment pipelines (CI/CD)

• Service communication issues

• Harder debugging and coordination between teams

Final Thoughts

There’s no one-size-fits-all answer. Both monolithic and microservices architectures have their place in the software world.

• Start small, move fast with a monolith.

• Gradually move to microservices as the product, users, and team grow.

Think of a monolith as building a compact house—perfect for a small family. Microservices are like a city—distributed, scalable, and managed by different authorities.

Choose what fits your needs now, and be ready to evolve as you grow.