[ There is a slack channel hosted on Mifos.slack.com called #Fineract. There are 368 participants on that channel and so it is a place where people are having discussions. My note to the host is to make sure content makes it back to the list if it is of broad interest... ]
A recent thread is perhaps useful to capture here for the listserv archive. It starts with Ahmed making a summary and asking questions... I then follow up. ================ FROM AHMED : Hi contributors As part of my journey to understand *Fineract's codebase and workflow*, I found the following videos which helped me to understand multiple things, and found it useful to share, already will help anyone . - Modularizing Fineract <https://youtu.be/8qp3zQGh5s4> - Monolith to Microservices: Modularizing Fineract 1.x <https://youtu.be/fn9uhpOWrHk> - Expanding Fineract capabilities <https://youtu.be/sfp7ox3wMKk> *I took some notes here, but for sure the videos are much more valuable.* - As the Fineract community and codebase grew over time, the monolithic architecture introduced natural scalability challenges. Core domain classes, such as Loan.java (exceeding *7,000 lines of code*) fineract is monolithic not microservices architecture but it's well structure. - For that, the need for modularity and separation comes into the scene, check this Picture <https://martinfowler.com/bliki/images/microservice-verdict/productivity.png> . - The flow of the application goes as follows: - External clients (web/mobile apps) send HTTP requests to the Fineract backend. - API layer (RESTful APIs developed with JAX-RS) receives the request - When receiving PUT or POST requests the attached JSON is stored as a string blob and is converted manually with GSON library to Java POJO. - A portion of the requests are translated into commands. - The commands are related to CQRS pattern for separation between Reads & Writes. (e.g. GLAccountReadPlatformService and GLAccountWritePlatformService) - The commands go to a spring injectable service for command processing (handler packages) which delegates the command to the service layer where business logic resides. - All The execution flow happens synchronously. - Check this image <https://github.com/apache/fineract/assets/87117386/d66494ec-41b2-467d-9ba3-4c6de7a4f2a0> - The code structure consists of 12 top-level <https://github-production-user-asset-6210df.s3.amazonaws.com/87117386/311600210-c11b5493-b0f4-4973-ab4b-dbe01e7c5e31.png?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Credential=AKIAVCODYLSA53PQK4ZA%2F20250420%2Fus-east-1%2Fs3%2Faws4_request&X-Amz-Date=20250420T015137Z&X-Amz-Expires=300&X-Amz-Signature=1679e4b6964f4fab1c740a89d04da7cce4ea176f1cbe4558c49ee0ac48f491b4&X-Amz-SignedHeaders=host> . - Identifiable patterns in the codebase: - api : The API layer that receives the client requests and is implemented with JAX-RS, which exposes some end-points that the client communicates with. - data : The *Data Transfer Objects* which encapsulates the data and transports it among different parts of the application which use Spring Data *JPA *(e.g. LoanRepository). - domain : Contain JPA/Hibernate (e.g., Loan, Client) entities that map between database tables and java classes. - serialization : responsible for de/serializing between *JSON* files and java *POJO*s - exception : hold the project exceptions. - utility : some utility classes that contain some reusable code. - handler : delegate the commands to the suitable service. - mapper : contains the mapper classes that are responsible for mapping between entities and DTOs. - service : the service layer which contain the business logic. Finally, these insights are personal effort (any feedback would be appreciated). What about my suggestions ? I recommend watch the videos and read documentation <https://fineract.apache.org/docs/current/> where you will find more info about the history and the challenges for scalability and consistency and how they have been tackled thanks for your attention. [image: YouTube] <https://www.youtube.com/>YouTube <https://www.youtube.com/> | The ASF <https://www.youtube.com/@communityovercode> Modularizing Fineract: The journey so far <https://youtu.be/8qp3zQGh5s4> <https://youtu.be/8qp3zQGh5s4> [image: YouTube] <https://www.youtube.com/>YouTube <https://www.youtube.com/> | The ASF <https://www.youtube.com/@communityovercode> Monolith to Microservices: Modularizing Fineract 1.x - A. Vidakovic, N. Ambali, I. Molnar, V. Romero <https://youtu.be/fn9uhpOWrHk> <https://youtu.be/fn9uhpOWrHk> [image: YouTube] <https://www.youtube.com/>YouTube <https://www.youtube.com/> | The ASF <https://www.youtube.com/@communityovercode> Expanding Fineract capabilities, a practical example - Frank Nkuyahaga <https://youtu.be/sfp7ox3wMKk> <https://youtu.be/sfp7ox3wMKk> (105 kB)
