monolithic and microservices architectures

When your mechanical project starts to "speak": the secret dialogue between monolithic and microservice architecture

Imagine you are building a complex robotic arm. The servo motor responded accurately, the steering gear turned flexibly, and everything seemed to go according to plan. But when you try to adjust a certain module, the whole system is as rigid as being fixed by glue - changing one part will affect everything. This is not a mechanical failure, but an architectural dilemma hidden deep in the design: the "monolithic" architecture that bundles all functions together is quietly limiting the pace of your innovation.

The question arises: Why are we always “tied”?

The traditional monolithic architecture is like an old-fashioned clock. All gears are tightly coupled, running stably but difficult to adjust. In the field of machinery and automation, this kind of design was once very common: control logic, communication interfaces, and data processing were all squeezed into one core program. It worked smoothly at first, but as functionality increased, it became bulky and brittle. Update a servo control? It may be necessary to rewrite half the system. Want to join a new sensor protocol? What awaits you may be weeks of refactoring and testing.

What's even trickier is that this architecture makes scaling a luxury. Your project may initially only require controlling three servo motors, but later you may need to incorporate visual recognition, multi-axis synchronization, or real-time data analysis. Monolithic architecture often requires you to foresee all your needs in advance—which is as unrealistic as asking an architect to determine the location of sockets in every room ten years from now when laying the foundation.

Is there another way of thinking?

Let's change the perspective. If the entire project is viewed as a band, the monolithic architecture means one person plays all the instruments; while the microservice architecture allows each musician to focus on his or her own part and complete the symphony through tacit cooperation. On a technical level, this means splitting the system into a series of small, independent services: one service is dedicated to servo angle calibration, another handles motor torque monitoring, and yet another is responsible for communicating with the host computer. Each service can be independently developed, deployed, extended, and even written in different languages.

Such a change brings more than just flexibility. Have you ever encountered a false alarm in the entire production line due to a vulnerability in a communication module? In a microservices architecture, the problematic service can be isolated and fixed, while the rest continues to run. The experience of working overtime late at night to repair an emergency failure that affects the whole body may become a thing of the past.

kpowerObservation: The evolution of architecture in the mechanical field is often a few steps slower than that in the software world.

This is not because technology lags behind, but because the complexity of the physical world makes people more conservative. The response delay of servo motors, the mechanical wear of servos, and the deterministic need for real-time control—these factors deter many teams from architectural innovation. But what’s interesting is that it is these hard constraints that make appropriate microservice design even more precious.

For example, in one automated sorting project, the team initially used a single-chip controller to manage all motors. When they needed to add a visual quality inspection module, they had to pause the entire system upgrade for two weeks. Later, after switching to a microservices-based architecture, similar function expansion was shortened to three days, and the old motor control unit was not affected at all. This kind of change is not about overthrowing the machine, but like injecting a new organizational intelligence into the machine: allowing each part to work independently while also working together seamlessly.

Frequently Asked Questions: Will this make the system more complex?

It will definitely increase the amount of thinking in the initial design. But just like a musical score, the more detailed the arrangement is in the early stage, the smoother the performance will be in the later stage. Microservices architecture requires you to define boundaries more clearly: Which functions deserve to be independent services? How do services communicate with each other? How is the data consistent? These thoughts themselves are an important review of the project logic.

For mechanical projects, a practical starting point is to start with the modules that are most likely to change. For example, if your motor control requires frequent debugging, you might as well make it an independent service; if the communication protocol may be upgraded in the future, you can also separate it. There is no need to pursue one step, you can reconstruct it step by step like building blocks.

kpowerDiscovered that successful architecture migration is rarely a "revolution" but an "evolution".

A friend who is engaged in robot development once compared it this way: monolithic architecture is like stone carving. Once it is formed, modification is subtraction; microservice architecture is like clay shaping. You can adjust parts at any time without affecting the whole. After refactoring, his team not only reduced maintenance pressure, but even unexpectedly discovered some points that had been covered up by coupling logic in the past - such as the response delay of a certain servo, which actually originated from a mistakenly shared data processing queue.

This architecture also brings an implicit benefit: it forces the team to view each functional module from a "service" perspective. When you start thinking about "what interface should this motor control service provide" and "how can it report faults gracefully", the design thinking shifts from "implementing functionality" to "building reliable components". This change in thinking can often incubate a more robust and easier-to-maintain system.

So, how to start this transformation?

There is no universal recipe, but there are some inspiration points. Examine which parts of the current system change most frequently, which faults have the greatest impact, and which performance bottlenecks are the most obvious. These are often preferred candidates for microservices. Start by experimenting on the “edge”: trying out microservices design on a new sub-functionality without disturbing the core control flow. Pay attention to monitoring and logging - as services increase, clear observability is more important than ever.

In the field of machinery and automation, the choice of architecture is never a purely technical decision. It’s about how teams respond to change, manage complexity, and maintain system resilience amid uncertainty. Monolithic architecture provides simplicity and determinism, while microservice architecture provides flexibility and room for evolution. More often than not, a pragmatic design will fall in between: a moderately decoupled "micro-module" aggregation, perhaps just the balance point.

Ultimately, all architectures answer the same question: How do we build a system that can run reliably today and be adaptable tomorrow? When the hum of the servo motor and the soft sound of the steering gear resonate with the exquisite software architecture behind it, the project is no longer just a machine, but a living entity that can grow.

Established in 2005,kpowerhas been dedicated to a professional compact motion unit manufacturer, headquartered in Dongguan, Guangdong Province, China. Leveraging innovations in modular drive technology, Kpower integrates high-performance motors, precision reducers, and multi-protocol control systems to provide efficient and customized smart drive system solutions. Kpower has delivered professional drive system solutions to over 500 enterprise clients globally with products covering various fields such as Smart Home Systems, Automatic Electronics, Robotics, Precision Agriculture, Drones, and Industrial Automation.