The Real Benefits of Micro Services in NestJS

This is an actual follow up from my article from almost a year ago where I ventured a bit into microservices of NestJS and later got carried away by daily tasks. Today I'd like to revisit this article and share my points.

You can find the article here.

Journey into MicroServices with NestJS

Recently, I’ve been contemplating increasingly on how to develop a SaaS product efficiently, aiming to bypass the typical project boilerplate that accompanies each new venture. You’re familiar with the usual suspects: authentication, teams, users, payments, and the admin panel. The admin panel often takes a backseat, as you can manage

Karolis ScerbiakasKarolis Ščerbiakas

Microservices have been widely promoted as a modern approach to software architecture, offering scalability, modularity, and resilience. But if you’ve experimented with both monorepos and multiple repositories while building microservices in NestJS, you may be wondering: Is this really worth the extra effort?

The truth is, microservices make sense only in specific scenarios. In many cases, they introduce unnecessary complexity rather than delivering tangible benefits. I am partially guilty myself of microservices hype until I tried the both. This article explores when microservices in NestJS are actually beneficial and when they just create more maintenance headaches.

🚀 The Real Benefits of Microservices (When They Actually Matter)

Microservices offer several key advantages, but these benefits only apply under specific conditions:

1. Scalability

If your application has components that need independent scaling, microservices can help optimize resource usage. For example:

• User Authentication might require fewer resources than AI Inference or Data Processing.
• Payment Processing might need to scale independently from an AI Inference or Audio Processing.

With microservices, you can allocate resources where they’re needed instead of scaling the entire monolith.

2. Team Independence

Large teams working on different parts of a system can avoid merge conflicts, coordination issues, and bottlenecks by working on separate microservices. This is particularly useful if you:

• Have multiple teams developing different services (e.g., one team handling payments while another manages user profiles).
• Want to enforce clear domain boundaries within your architecture.

3. Technology Flexibility

Microservices allow you to use different tech stacks for different services. This can be helpful when:

• You need Python for AI processing, Node.js for APIs, and Go for high-performance tasks.
• You’re integrating with legacy systems that require different languages or frameworks. This works especially well in scenarios when migrating from older tech stacks to a newer ones - this the approach I've taken in my career.

4. Deployment Speed

With microservices, you can deploy and update individual components without redeploying the entire system. However, in reality, this advantage is often overstated unless you have:

• Strict uptime requirements (e.g., financial transactions, real-time analytics).
• A CI/CD pipeline that fully supports independent deployments.
• A high-frequency release cycle where different services need to be updated at different times.
• Less relevant with serverless or kubernetes deployments.

5. Fault Isolation

If one microservice crashes, it doesn’t necessarily bring down the entire system. This is beneficial for:

• High-availability applications where downtime must be minimized.
• Error-prone components that shouldn’t affect the rest of the system.

For example, a failing recommendation engine shouldn’t prevent users from logging in or making payments. But this is an ideal world example. Most of the time service integration is rarely integrated so well that users wouldn't notice. While argument can be valid, but in reality this is rarely the case, because most of microservice deployments are monolith sewn via HTTP (or any other transport layer in that matter).

🤔 Why Microservices Might Not Be Worth It for You

If you’re a solo developer or working in a small team, microservices might be making your life unnecessarily difficult. Here’s why:

1. More Maintenance Overhead

With microservices, you need to keep APIs, data contracts, and inter-service communication in sync. This means:

• Constantly managing API changes and versioning.
• Handling data consistency issues between services.
• Ensuring that services communicate reliably (REST, gRPC, message queues, etc.).

2. Increased DevOps Complexity

Running microservices at scale usually requires Kubernetes, service discovery, logging, monitoring, and distributed tracing. This means:

• More infrastructure management (containers, orchestrators, etc.).
• More debugging complexity (tracing issues across multiple services instead of a single monolith).

This isn't as bad when monolith is deployed on Kubernetes, with proper visibility it is not as bad as it sounds.

3. Performance Overhead

Instead of in-memory function calls, microservices introduce:

• Network latency (especially if services are making frequent calls to each other).
• Serialization and deserialization overhead.
• Retry logic and failure handling for inter-service communication.

4. More Boilerplate Code

With microservices, authentication, data synchronization, and error handling become significantly more complex:

• Handling authentication and authorization across multiple services.
• Implementing service-to-service communication securely.
• Managing distributed transactions (e.g., Saga pattern).

🎯 When NestJS Microservices Actually Make Sense

Since you’re using NestJS, microservices can be beneficial if:

• You genuinely need an event-driven architecture (e.g., Kafka or Redis-based event processing).
• Your system has clear domain boundaries that require separation (e.g., finance vs. analytics vs. user management).
• You need to integrate with external services that require isolated logic.

For example, if you’re building a modular, event-driven system where different services react to events asynchronously, NestJS’s microservices support can be a great fit.

🔥 The Real Talk

Most startups and even mid-size projects do just fine with a well-structured modular monolith in NestJS. You can always break it into microservices later if needed (if NestJS modules well architected that is). The idea that you must start with microservices from day one is a common misconception. This is what I love about NestJS. You can start it as a monolith and because of the boiler plate you usually then to write you can move modules into other services in organized manner without risking too much.

👉 Unless you’re hitting real bottlenecks, microservices are just added complexity.

TL;DR

• Microservices make sense when you need scalability, team independence, fault isolation, or multi-tech stacks.
• They are overkill if you're a solo developer or a small team without high scalability needs.
• A modular monolith in NestJS is often the best starting point—microservices can come later if required.