Microservice
also: microservices, microservice architecture
An approach where an app is split into many small, separate programs, each handling one feature and running on its own.
An architecture where the system is split into independently deployable services, each owning one business capability and usually its own data, talking over the network through APIs or queues. It helps large organizations scale teams, at the cost of network failures, data consistency problems and operational overhead.
A food court: separate stalls for pizza, tacos and drinks, each with its own staff and kitchen. Great for huge crowds, but one meal now means three lines and some coordination.
Agents sometimes propose microservices because they sound professional. For a small app, they usually add cost and failure points. Knowing the tradeoff lets you say no with confidence.
One option is extracting notifications into a microservice. Given your current scale, I'd recommend keeping it in the monolith as a separate module.
Before suggesting microservices, explain what specific problem splitting would solve for us now, and what it would cost in hosting, deployment and debugging.
Thinking microservices are the modern, better way for every app. They solve problems of large teams and huge scale, which small apps don't have.