Remember when Instagram processed 14 million users through a single Django application? Or when Shopify managed billions in revenue with a monolithic Ruby on Rails app?
While the tech world buzzes about microservices, some of the most successful companies started with - and many still maintain - monolithic applications.
Yet somewhere along the way, the term “monolith” became a dirty word in tech circles. Developers and architects, enchanted by the promise of microservices, often rush to break applications into tiny, distributed pieces before understanding if that complexity is really necessary.
In this article, we’ll explore why starting a “majestic monolith” often makes more business sense, when microservices might be the right choice, and how to make this crucial architectural decision for your project.
Understanding monoliths and microservices
Let’s break this down with a real-world example. Consider an e-commerce website. With a monolithic structure, all the features—user accounts, product catalog, shopping cart, payment processing—are part of one unified application. All your store operations are under one roof. When a customer makes a purchase, the entire process flows smoothly through a single system.
Now, imagine the same e-commerce site built with microservices. Each function becomes its own independent service: one for user management, another for the product catalog, and separate ones for the shopping cart and payments. This separation might offer flexibility, but it also means that a simple purchase now requires multiple services to communicate flawlessly with each other.
Why premature microservices can cost you
When teams rush to adopt microservices too early, they often discover hidden costs that can derail their projects.
Communication becomes complex
In a monolith, different parts of your code can talk to each other directly. With microservices, every communication between components has to travel across a network. This not only adds latency but also introduces numerous potential points of failure.
Infrastructure overhead
Each microservice needs its own deployment process, monitoring, scaling mechanisms, and possibly its own database. The complexity of it all can overwhelm smaller teams.
Debugging is a nightmare
When something goes wrong in a monolith, finding the problem is relatively straightforward – all the code and logs are in one place. But with microservices, a single user request might touch dozens of them, making it exponentially harder to trace problems when they occur.
Data inconsistency
Perhaps the most underestimated challenge is maintaining data consistency across services. In a monolith, transactions are straightforward. Microservices, on the other hand, have to coordinate transfers between each other since each one has its own database. They all have to stay in sync, which can become a significant architectural challenge.
Why monoliths work better for most startups
Startups that are launching a new product often benefit more from a monolith because of its speed and simplicity. Despite its unsexy reputation in some tech circles, it provides exactly what startups need to succeed.
Successful startups like Basecamp, GitHub, and Shopify all started with monolithic applications, and some still primarily use them today. This is because monolithic applications let you focus on what really matters, which is building and refining your product. They nail the basics and allow you to add complexity later on.
With a monolith, your entire codebase is in one place. Developers can quickly make changes, test features, and deploy updates without coordinating access to multiple services. Need to add a new feature? Just write the code and deploy it. No need to create new services, set up additional databases, or deal with complex network communications.
Starting with a monolith means there’s less infrastructure to manage and fewer specialized tools to maintain. Less need for servers, deployment pipelines, and monitoring systems. For a startup watching its burn rate, this difference can be huge.
New team members can get started faster because they don’t need to understand complex services or interactions or learn multiple deployment processes. Instead, they can focus on learning one coherent system.
When to break up your monolith
There are legitimate reasons to consider breaking your monolith into microservices. But timing is everything. You may need to make the switch if your development team grows beyond 50 people, all working on the same codebase. Things can get messy. They start stepping on each other’s toes, and coordination becomes a nightmare. At this point, breaking the application into separate services can help them work independently and move faster.
Another situation that makes sense is when certain parts of your application have unique scaling needs. Take Netflix, for example. Their video streaming service needs to handle millions of concurrent users, while their billing system has much lower traffic. In a monolith, you’d have to scale everything together. But with microservices, you can scale just the components that need it.
As your product matures, you’ll start to see natural divisions in your application. Maybe your user authentication system has become complex enough to warrant its own service, or your recommendation engine needs special attention. These divisions should be evident from real-world usage, not theoretical planning. And so when you recognize this, it’s better to break up your monolith.
Sometimes, different parts of your system need different technologies to work best. You don’t have to be stuck with one technology stack when you can get a component that’s the best tool for its specific job.
Making the right choice for your business
While microservices might be the eventual destination for some successful applications, starting with a well-structured monolith is often the wisest path forward.
At Plumelo, we've helped numerous companies navigate these architectural decisions. Our experience shows that most successful projects start simple and evolve based on actual needs rather than theoretical benefits.
Ready to discuss your project's architecture? Let's talk about building a solution that grows with your business – starting with the right foundation.
References
https://highscalability.com/instagram-architecture-14-million-users-terabytes-of-photos/
https://shopify.engineering/shopify-open-source-philosophy#
https://www.cloudflight.io/en/blog/the-hidden-cost-of-microservices-and-how-to-overcome-them/
https://buttercms.com/books/microservices-for-startups/should-you-always-start-with-a-monolith/
https://hackernoon.com/when-to-break-the-monolith-identifying-obstacles-in-your-software
