Reporting Service in Spring Boot: Turning Raw Events into Board-Ready Metrics

Today I switched from payments to the challenge every board asks for: trustworthy dashboards.

I built a Reporting Service that turns raw events into executive-level metrics.

📊 What went live

• Daily snapshots using Spring Batch + SQL ON CONFLICT → no more recomputing six months of data.
• Insight APIs powered by JPA projections + Redis cache → dashboards respond in milliseconds.
• Self-service exports (PDF/CSV) via Thymeleaf templates + OpenPDF, with S3 upload and email delivery.
• RBAC/OAuth2 → finance sees everything; leadership only what’s relevant.
• Observability: metrics (reporting.batch.duration, reporting.export.count) feeding Grafana and Kibana.

💡 Why it matters

• Provides full traceability — no hidden spreadsheets.
• Frees squads from daily “can you pull this report for me?” requests.
• Keeps OLTP healthy: aggregations and exports run in isolation.

📚 Full deep dive (+ code)

• Blog version: https://enouveau.io/blog/2025/11/10/reporting-service-under-the-hood.html
• Repo: adelmonsouza/30DiasJava-Day10-ReportingService
• Projeto pessoal: Este é um projeto do desafio #30DiasJava, mantido independentemente para fins educacionais.

Next episode → Day 11/30 — Logging Service in Spring Boot