CoolLib — Distributed Library Hub: A Clean Architecture Implementation
Spring Boot
Docker
Nginx
PostgreSQL
Cloudflare R2
JWT Security
Kotlin
A high-performance distributed system built on Clean Architecture, with a Dockerized backend orchestrating core business logic and persistence via PostgreSQL. Cloudflare Edge provides global delivery through CDN caching and secure tunneling, while R2 enables zero-egress static asset storage. Real-time observability is powered by Cloudflare Workers, supporting reactive data flow for Android (Kotlin) and iOS (SwiftUI) clients.
Architecture Design
flowchart LR
subgraph Clients ["`**Clients**`"]
A(Android
Compose)
B(iOS
SwiftUI)
end
subgraph CF1 ["`**Cloudflare Edge (Delivery)**`"]
G1{CDN
Cache}
R2[(R2
Storage)]
C{Tunnel}
end
subgraph CF2 ["`**Cloudflare Observability**`"]
W(Worker
Monitor)
D1[(D1
Metrics)]
MON(Monitor
Dashboard)
end
subgraph Docker ["`**Docker Infrastructure**`"]
D(Nginx
Proxy)
E(Spring
Boot)
H[(Postgre
SQL)]
end
%% =========================
%% FLOW
%% =========================
A e1@--> G1
B e2@--> G1
G1 -- "Static Assets" --> R2
G1 -- "API Requests" --> C
C e3@--> D
D --> E
E --> H
%% Observability (clean separation)
E e4@--> W
W --> D1
D1 --> MON
W --> MON
%% =========================
%% animations
%% =========================
e1@{ animation: slow }
e2@{ animation: slow }
e3@{ animation: slow }
e4@{ animation: slow }
%% =========================
%% CLIENT LAYER (brand light)
%% =========================
style A fill:#22c55e,stroke:#16a34a,stroke-width:2px,color:#fff
style B fill:#0A84FF,stroke:#0066cc,stroke-width:2px,color:#fff
%% =========================
%% CLOUDFLARE LAYER (unified blue system)
%% =========================
style G1 fill:#3b82f6,stroke:#2563eb,stroke-width:2px,color:#fff
style C fill:#3b82f6,stroke:#2563eb,stroke-width:2px,color:#fff
style R2 fill:#60a5fa,stroke:#3b82f6,stroke-width:1px,color:#fff
%% =========================
%% OBSERVABILITY (light blue system)
%% =========================
style W fill:#93c5fd,stroke:#3b82f6,stroke-width:2px,color:#fff
style D1 fill:#bfdbfe,stroke:#60a5fa,stroke-width:1px,color:#fff
style MON fill:#3b82f6,stroke:#2563eb,stroke-width:2px,color:#fff
%% =========================
%% BACKEND (UNIFIED SYSTEM COLOR)
%% Nginx + Spring + PostgreSQL = ONE SYSTEM
%% =========================
style D fill:#64748b,stroke:#334155,stroke-width:2px,color:#fff
style E fill:#475569,stroke:#334155,stroke-width:2px,color:#fff
style H fill:#334155,stroke:#334155,stroke-width:2px,color:#fff
style Clients fill:#f8fafc
style CF1 fill:#f1f5f9
style CF2 fill:#f8fafc
style Docker fill:#f1f5f9
%% =========================
%% LINKS
%% =========================
linkStyle default stroke:#94a3b8,stroke-width:1.5px
Cloudflare Edge-secured system with Dockerized backend and real-time observability.
Developed with passion by Ryan Su © 2026