CMS Platform · Spring Boot 3.5 · Java 21

Elly

A powerful multi-tenant Content Management System designed for speed, isolation, and scalability.

PostgreSQL · DB-per-Tenant

Redis Cache

RabbitMQ

JWT + OAuth2

Kubernetes-ready

What is Elly?

Overview and four pillars

Elly is a headless CMS and rapid MVP platform built on Spring Boot 3.5. Pages, components, dynamic forms, asynchronous email and user authentication — all isolated per tenant.

Content

Page → Component → Banner / Widget → Post → Comment / Rating

Auth

User → Role → Permission · Login · Register · RefreshToken · OAuth2

Form

FormDefinition (JSONB) → ConditionEvaluator → FormSubmission

Email

MailAccount → Async Queue → Thymeleaf → Gmail SMTP

All Domain Entities

PageComponentBannerWidgetPostFormUserPermissionCommentRatingAssetsEmailMailAccountRefreshTokenSeoInfoRoleFormDefinitionFormSubmission

Auth Architecture

JWT flow, OAuth2, and refresh tokens

JWT Login Flow

POST /api/auth/login
AdminLoginInterceptor · TenantLoginInterceptor
JWT Generation
Access + Refresh · loginSource & tenantId claim
POST /api/auth/refresh
Validate · revoke check · issue new Access

Registration & OAuth2

POST /api/auth/register
Create user · assign role · async verification email
OAuth2 Providers
Google · Facebook · GitHub → SuccessHandler → JWT
Redis Auth Cache
auth:user:{username} · TTL 30m · 3 SQL → 1 GET

Field	Description
token	UUID · unique per session
expiryDate	LocalDateTime
revoked	Boolean · logout flag
user	ManyToOne → User

Form System

JSONB schema, validation strategy, conditional fields

FormDefinition (JSONB)

idUUID · Primary Key
versionInteger · schema versioning
schemaJSONB → FormSchema (fields + config)
activeBoolean · publish state

FieldDefinition

typetext · select · number
validationmin · max · regex pattern
conditionConditionRule: field · operator · value
operatorsEQUALS · NOT_EQUALS · GT · LT

Strategy Pattern

TextFieldValidator → min/max length, regex

NumberFieldValidator → range, integer check

SelectFieldValidator → allowed values

Submission Flow

1.Fetch FormDefinition
2.Iterate fields → ConditionEvaluator
3.Hidden → strip key from payload
4.Visible → run FieldValidator strategy
5.Cleaned → save FormSubmission (JSONB)

Email System

Async messaging, retry & DLQ

Async Mail Pipeline

1. POST /api/v1/emails/sendJWT-protected endpoint
2. EmailLog PENDINGPersisted to DB · 202 Accepted returned immediately
3. RabbitMQ email-queueOnly emailLogId is published
4. ConsumerFetch log → Thymeleaf render → TenantMailSenderFactory → Gmail SMTP
5. Success / FailureSENT · retry-queue TTL 30s · max 3× → FAILED + DLQ

MailAccount (Per Tenant)

smtpHostsmtp.gmail.com
smtpPort587 (TLS)
passwordAES-256 encrypted
verifySMTP test before send

EmailLog & Rescue Job

EmailLog fields: recipient · subject · templateName · payloadJson · status · retryCount · errorMessage · sentAt

EmailRescueJob: @Scheduled every 5 minutes · finds PENDING records older than 5 minutes · re-queues batches of 50.

Layered Architecture

Controller → Service → Repository → Entity

IController

Interface contracts, endpoint signatures

@RestController

Controller

HTTP layer, request parsing, response wrapping

RootEntityResponse<T>

IService → Service

Business logic, caching, tenant context

@Cacheable@Transactional

Repository

Spring Data JPA, Entity Graph queries

@EntityGraph

Entity + DTO

MapStruct mapping, Entity never exposed via API

MapStructLombok

☕

Java

21 LTS

🍃

Spring Boot

3.5.7

🐘

PostgreSQL

Multi-DB

⚡

Redis

Cache

🐇

RabbitMQ

Queues

☸️

Kubernetes

K8s

Multi-Tenancy

Database-per-tenant isolation

JWT Token

tenantId claim

→

JwtTenantFilter

TenantContext.set()

→

TenantDataSourceRouter

AbstractRoutingDataSource

→

elly_basedb

elly_tenant1

elly_tenant2

Full Isolation

Each tenant has its own PostgreSQL database. Cross-tenant data leaks are impossible.

ThreadLocal Context

TenantContext uses ThreadLocal for request-scoped isolation; guaranteed cleanup in finally blocks.

HikariCP Pools

Each tenant DB has its own optimized HikariCP pool — no resource contention.

Redis Cache Isolation

Cache keys prefixed: {tenantId}::{cacheName}::{key} — automatic tenant-scoped scope.

Security & Authentication

JWT, OAuth2, RBAC and granular permissions

JWT Auth

Access + Refresh token pair
tenantId & loginSource claims
Redis auth cache — TTL 30m
3 SQL → 1 Redis GET

OAuth2

Google · Facebook · GitHub
OAuth2AuthenticationSuccessHandler
Seamless JWT integration
Stateless by design

RBAC

User → Role → Permission (M2M)
SUPER_ADMIN · ADMIN · EDITOR · VIEWER
40+ granular permission constants
@PreAuthorize · @EnableMethodSecurity

Role	Scope	Permissions
SUPER_ADMIN	All tenants	Full system · tenant management
ADMIN	Own tenant	All CMS operations · user management
EDITOR	Own tenant	Create/update content · publish
VIEWER	Own tenant	Read-only content access

Performance Profile

Before/after metrics and optimization priorities

Response Time p95

2340ms456ms

Throughput

18 req/s187 req/s

DB Queries / Request

47 queries1 query

HIGH

N+1 Query Fix with @EntityGraph

47 queries → 1 query per request

HIGH

HikariCP Pool Size 10 → 50

Prevents connection exhaustion under load

HIGH

Database Indexes on FK columns

Eliminates full table scans — 5–10× speed

MID

Pagination on all list endpoints

Prevents OOM on large datasets

MID

Tenant-prefixed Redis @Cacheable

50–100× on cache hits, graceful fallback

LOW

Read replica + CDN (file uploads)

Scale read operations horizontally

Deployment & Infrastructure

Kubernetes, observability, mail system, CI/CD

Kubernetes Setup

App Deployment2a-app-deployment.yaml
Burst Config2b-app-burst.yaml
HPA Autoscaler5-hpa.yaml
Monitoring6-monitoring.yaml

Services & Observability

PostgreSQLMulti-DB · Backup CronJob
RedisTTL=10min · Graceful fallback
RabbitMQemail-queue · retry · DLQ
PrometheusSpring Actuator metrics
GrafanaReal-time dashboards
SonarQubeCI quality gate

Mail System

Tenant SMTPAES-256 encrypted credentials
Async sendingRabbitMQ email-queue
Retry logic3× with 30s backoff
Dead letter queueFAILED + DLQ on exhaustion
Verification endpointSMTP test before send

CI/CD & Load Tests

GitHub ActionsBuild → Test → Deploy
DockerDockerfile + docker-compose
k6 Load Testsbaseline · stress · write suites
SonarQubeQuality gate in pipeline

Current Status & Roadmap

Summary metrics and next steps

Tenants

40+

Permissions

10×

Perf. Gain

K8s

Production-ready

Now · High Priority

Database index rollout
Connection pool → 50
Entity Graph for N+1 fix
Pagination on all lists

Soon · This Sprint

DTO pattern everywhere
Redis cache rollout
Async file upload
Load test baseline + retest

Later · Scaling

Read replica setup
CDN for file uploads
Multi-region K8s
Dynamic tenant onboarding