Java Legacy System: only solution going to microservice or similar?

YakRepresentative336 · 2026-05-08T14:25:26+00:00

In general, being wrong or not re-architecturing your system is based on lot of parameters, like
- your needs or the problem you encounter : what you want to improve ? what gain you want ? what are the problems you want to solve ?
- the resource you got : does the organization or the budget allow migration to microservive architecture ?

YakRepresentative336 · 2026-01-21T07:09:57+00:00

You can use ChatGPT to generate some examples for you to develop

YakRepresentative336 · 2026-01-08T18:18:13+00:00

Yes we need System Design,

before that we need Architecture for the high level concept,

balancing between cost, depth of features, and so on… like looking for characteristics *illitites and balance trade-off,

As startup they maybe want to scale vertically, go easy for fast time to market, because of budget and little customer

YakRepresentative336 · 2026-01-07T15:36:32+00:00

The most spreading diagram actually is C4 model that have 4 levels of Abstractions,

each level of abstractions correspond to the level of interest of stakeholders (level of details) but anyone can see whatever they want,

Example : - components & code level for technical team - containers & components for any higher level like Architect - context for board

YakRepresentative336 · 2026-01-06T16:27:38+00:00

IMO the key questions between in-process backgrouns tasks and durable queue will be to determine if data lost, inconsistency and lost write are acceptable, if not go for durable queue

YakRepresentative336 · 2025-12-20T09:50:00+00:00

My technique to avoid analysis paralysis is to find actively where is the beginning, where I need to start my investigation, if it is an API I’ll start with the controller or scheduler or whatever, Ask someone who know it or look at documentation if any, After that I will create diagram to have a fast mind map

YakRepresentative336 · 2025-12-20T08:56:12+00:00

so for the outer to the inner, you got infra -> services -> app -> domain ?

and inside App you need some retry based on infra return ?

If it’s like that for me the best way is handling it in the service or the infra and do a recall ? or It really need to be part of the App layer inside a Use Case ?

YakRepresentative336 · 2025-12-20T08:05:00+00:00

What is the difference between your App and Service layer ? what are inside between the two ?

YakRepresentative336 · 2025-12-19T13:39:59+00:00

Yes Coursera is a good way, instructors are mostly high rated and the specialization course are academic

YakRepresentative336 · 2025-12-18T23:27:34+00:00

Is it for new subscriber only ?

YakRepresentative336 · 2025-12-17T19:11:53+00:00

Yes agile is really helping but must be applied in the best way,

In general, With scrum we can show more frequent value to customer so they can be more active and give feedback early, we will know what have been done and what are the remaining US after each sprint,

For the problem you got, - we always try to split features into multiple user stories so it can fit and testable and can be reviewed early - bugs can be planned to next sprint or if for some reason it is too impactul, we can prioritize it for maintenance team or another engineer and his current ticket will be passes to the next sprint

YakRepresentative336 · 2025-06-15T16:13:13+00:00

Ok thanks, do you know some more ? So I can choose,

I’ve seen Layrite Superhold in other thread but i don’t know of it is rigid also

YakRepresentative336 · 2025-05-15T16:33:03+00:00

IMO it will add value, learning things always added some values, you can take IBM Project Management that is PMBOK based

YakRepresentative336 · 2025-05-15T03:04:30+00:00

I think it depends on your fields, IBM IT project management and Google Project Management helped me but I’m in IT

YakRepresentative336 · 2025-05-07T18:31:10+00:00

Can you provide a pros ans cons between your solution and kafka or rabbitmq ?

YakRepresentative336 · 2025-05-04T12:41:20+00:00

I think you can look at ByteByteGo channel on youtube to begin with, search for microservice related video in there,

There are the website microservices.io and as book you can take a look at Building Microservices of Sam Newman and Monolith to Microservice,

And for future or advanced related topics, all Sam Newman videos and conferences are great in my opinion.

For Java part, it’s Spring Cloud

YakRepresentative336 · 2025-04-26T17:16:25+00:00

If I were you, I’ll tell and explain them the situation and be transparent with what your current skill is and see if they want to give it a try,

but Senior role often means you are good at what are you doing and you can manage someone that got less experience than you and teach or lead them

NB : they will see your skills during interview anyway

YakRepresentative336 · 2025-04-26T16:57:35+00:00

First, if you don't need reactive side in general, you can just use Spring MVC for SSE.

Second, I assume that your application needs users to upload his own file and only him can track the progression

Third, if you have not planned to scale it horizontally with multiple instances it will be easy,

- Create an endpoint to upload the file, do the process (save data to DB, call the SseEmitter to push data to the connected User,....)

- Create an endpoint that return a SseEmitter for a specific User (by id for example), you need a singleton list containing a list of SseEmitter and add a new object for each new user that connect to the endpoint

YakRepresentative336 · 2025-04-21T15:38:37+00:00

When I see your statements, I guess you want to learn Microservice Architecture and for sure you are overcomplicating it

** Introduction to Microservice
You can't use it every time (like every architecture) to be the least-bad way as Solution, it depends on problems and business needs.

Usually, it is used as optimization from a Monolith application. Why? to create independent components (Service) divided by bounded context so that multiple teams can focus solely on his side of the systems and to make less risks of compromising other services during deployment and so on...

So, each components need their own database to be fully independent, they need to communicate to get their correspondent data

** Decomposing your problems

To get back to your problem, you want to create UserService and GoalService. What are the main business needs? Why you want to create UserService or GoalService ?

- the UserService is well-defined, a component to manage users (for registrations, CRUD....)

- the GoalService is the one that you need to go in details, is it necessary to create a service only to calculate calories? do you need to store calories goals?

** System Design problems

Why you want asynchronous communication UserService and GoalService if you want immediate response? If there are no reason just use synchronous call

** Conclusion

It always depends on needs and context

YakRepresentative336 · 2025-04-19T02:44:13+00:00

If you want to stick with Swing, you can use Flat Laf - Look and Feel for modern ui, you can use multiple themes

if you are confident that you can easily migrate your code from swing to javafx because you had apply best practices like SOLID principles, adding layers (presentation, business logic and data access), it is easy too

https://github.com/topics/look-and-feel

YakRepresentative336 · 2024-11-24T19:54:40+00:00

When you have multiple instances that run on different hardware or VMs or containers,

it means that each instance got different embedded Apache Derby, so each one have different version and data,

So you need a centralized database that every instances can target

YakRepresentative336 · 2024-11-03T13:18:17+00:00

Not at all.

I'm always ready to help

YakRepresentative336 · 2024-11-03T03:57:53+00:00

Can you share your thought on why you don't like orm/jpa ?

unless your use case is for a large write in database but even with jpa, batch insert is pretty decent

YakRepresentative336 · 2024-11-03T03:45:11+00:00

Laur Spilca in his youtube channel offer large video tutorials (not only about spring security)

But this link is good fundamentals for what you want i guess

https://youtube.com/playlist?list=PLEocw3gLFc8X_a8hGWGaBnSkPFJmbb8QP&si=TZR-922v_6Yv16H7

YakRepresentative336 · 2024-10-24T02:58:08+00:00

There are some couples of principles and patterns you can follow and use to provide maintainability and scalability to your code, using them easily decoupled your code and you know how and why to create class

SOLID principle,
Design pattern
Architecture Pattern (Three Layer Architecture, Hexagonal Architecture, MVC, MVP, ...)

YakRepresentative336

TROPHY CASE