Architectural Styles for Machine Learning Model Deployments: The Monolithic Application vs. The Decoupled API Approach

Matt The Cloud Engineer
ParagonCloudConsulting
3 min readMay 27, 2023

Machine Learning (ML) has seen remarkable advancements in recent years. One of the key challenges in leveraging these advancements is choosing the right architectural style for deploying ML models, and there is no one-size-fits-all solution. Two such deployment strategies often discussed are: the monolithic application approach, where the ML model is embedded directly into the application, and the decoupled API approach, where the model is separated from the application and accessed through an API. This article will delve into both strategies and their respective advantages and disadvantages.

Monolithic Application Approach

In the monolithic application approach, the machine learning model is part of the application. Every time the model is updated, the entire application is redeployed. This style is akin to a tightly-knit sweater — every thread (or part of the application) is intimately connected to the others.

The primary advantage of this deployment strategy is simplicity. Integrating the model within the application simplifies the architecture and reduces the number of moving parts. This results in lower initial setup complexity and can also improve performance, as there are no network overheads for calling an external API to access the model.

However, this approach has several disadvantages. First, redeploying the entire application to update the model can be time-consuming and operationally complex. This might introduce unnecessary downtime for the application and impact the user experience negatively. Second, as the ML model is tightly coupled with the application, the ability to experiment with different models or versions is limited. Lastly, scaling the model can be challenging as it would require scaling the entire application, which may not always be desirable or feasible.

Decoupled API Approach

In contrast, the decoupled API approach keeps the ML model separate from the application. The application interacts with the model through an API, allowing the model to be updated or changed without redeploying the entire application.

This deployment strategy is advantageous in many ways. It provides flexibility for updating and experimenting with the model, as it can be changed without affecting the application. This leads to faster deployment cycles for the model and less disruption to the end-users. It also supports better scaling options, as the application and the model can be scaled independently based on their respective needs.

However, the decoupled API approach introduces more complexity into the system architecture. The application now has to handle the communication with the model API, and care must be taken to ensure the API is reliable and secure. Additionally, this approach may introduce performance overhead due to network latency in API calls.

In conclusion, the choice between a monolithic application and a decoupled API approach for ML model deployment depends largely on your application’s specific needs and constraints. If simplicity and performance are paramount, the monolithic approach might be best. However, if flexibility, scalability, and experimentation are more important, the decoupled API approach might be the better option.

Remember, these are not the only two ways to deploy ML models. Other options, such as microservices architecture, are also worth considering based on the nature and needs of your application. As a technologist, the key is to understand the trade-offs involved and make informed decisions to enable efficient and effective use of machine learning models in your applications.

And don’t forget, the world of ML is fast-paced and constantly evolving. Stay curious, keep learning, and keep experimenting. Your next deployment could be the one that revolutionizes your application and the experiences it provides to users

--

--

Matt The Cloud Engineer
ParagonCloudConsulting

A full stack engineer turned devops turned AI and MLops that has a love for classical guitar and VR gaming!