My company is planning to use Java for backend services and Rails for the frontend web application. The Java side would handle database caching and core business logic, while Rails would power the user interface and admin dashboard.
I’m curious about real world examples of this architecture pattern. Has anyone worked with similar setups before? What challenges did you face with things like:
Development workflow and team coordination
Deployment complexity
Performance and scaling issues
API integration between the two systems
Looking for practical insights from developers who have actually implemented this kind of split architecture. Stories about what worked well and what didn’t would be really valuable. I want to avoid theoretical discussions about other frameworks unless they’re directly relevant to this specific Java/Rails combination.
We did something similar at my last company for a fintech platform. Java handled transactions and risk calculations, while Rails ran the customer portal and internal tools. Keeping data consistent between both systems was our biggest headache. We fixed it with event-driven architecture and message queues - without that, we’d constantly fight stale data.
Deployments got messy fast since API changes needed coordination between teams. API versioning and clear service contracts saved us there. Bonus: teams got specialized. Java devs focused on business logic optimization, Rails devs owned user experience. Productivity jumped once we nailed team communication.
Performance-wise, we could scale each piece independently. Optimizing database connections and caching on the Java side didn’t mess with Rails response times. My advice: invest hard in automated API contract testing and get solid monitoring across both systems from day one.
been there, done that mess lol. biggest gotcha for us was debugging issues across both systems - logs everywhere and figuring out which service actually broke was a nightmare. also watch out for circular dependencies when rails needs data from java but java calls back to rails for user context stuff. we ended up with weird coupling issues that took months to untangle.
nice setup! how do you handle user sessions between the two systems? when someone logs into rails, how does that auth carry over to your java services - jwt tokens or something different? and for dev work - do developers run both rails and java locally, or is there another approach?