Cloud infrastructure AWS, polyglot tech stack, migration path dari PHP monolith ke Go/Node.js microservices, dan diagram arsitektur Strangler Fig.

🏗️ Arsitektur & Tech Stack (Deep Intel)

Cloud Infrastructure — AWS

AWS Service	Fungsi di SEVIMA	Relevansi untuk Kita
Amazon RDS	Backbone transaksional ACID — nilai akademik, payment gateway	Pengalaman Kafka + PostgreSQL di BTPN
Amazon S3	Repositori objek petabyte-scale — materi kuliah, tesis, multimedia	Standard, familiar
Amazon EKS	Kubernetes container orchestration untuk microservices	✅ DIRECT MATCH — ini yang mereka hire!
AWS Lambda	Event-driven serverless (masa depan) — trigger dari S3/API Gateway	Bisa jadi proposed scope
Graviton2/ARM64	Eksplorasi efisiensi compute DB workloads	Nice-to-know

Key Architecture Insight

SEVIMA mencapai zero-downtime saat COVID surge 10x traffic (700+ PT simultan). Ini membuktikan EKS + RDS mereka sudah battle-tested. Tantangan sekarang: dekomposisi further dari monolith PHP → microservices Go/Node.js. Itulah kenapa mereka hiring.

Tech Stack — Polyglot Architecture

LEGACY LAYER (masih aktif, perlu modernisasi):
├── PHP (Laravel / Symfony) — MVC core business logic
├── Monolithic architecture — masih ada coupling
└── Problem: setiap perubahan modul bisa cascade ke modul lain

MODERN LAYER (sedang dibangun — INI POSISI KITA):
├── Go (Golang) — konkurensi tinggi, hemat memori
│   → goroutines untuk KRS race condition (ribuan write-requests simultan)
│   → Sync services, queue management
├── Node.js — async I/O intensive
│   → Real-time chat, push notifications, dashboard live updates
├── Python — analytics & complex logic
├── Java / Rust / C++ — system-level services
└── gRPC + REST — inter-service communication

FRONTEND:
├── ReactJS — Single Page Application (SPA)
├── Progressive Web Apps (PWA) — inklusivitas low-end devices
└── Native Mobile + iOS SDK

INFRASTRUCTURE:
├── Docker — containerization (WAJIB di job desc)
├── Kubernetes (EKS) — orchestration
├── AWS (RDS, S3, EKS, Lambda)
└── CI/CD pipeline

ENGINEERING CULTURE:
├── Test-Driven Development (TDD) — wajib
├── Unit Testing — massive coverage
├── QA Automation — menggantikan manual QC
├── Code Reviews — harian oleh Engineering Manager / Senior
└── Mentorship — structured knowledge transfer

Migration Path (Inilah Yang Mereka Butuhkan)

CURRENT STATE:            TARGET STATE:
┌─────────────────┐      ┌──────────────┐  ┌──────────────┐
│   PHP Monolith  │      │ Auth Service │  │ Payment Svc  │
│   (Laravel)     │  →   │   (Go/gRPC)  │  │  (Go/gRPC)   │
│                 │      └──────────────┘  └──────────────┘
│  SIAKAD + LMS   │      ┌──────────────┐  ┌──────────────┐
│  + Payment      │  →   │ Academic Svc │  │ LMS Service  │
│  + PMB          │      │   (Go/gRPC)  │  │ (Node.js)    │
│  + Everything   │      └──────────────┘  └──────────────┘
└─────────────────┘      ┌──────────────┐  ┌──────────────┐
                         │  PMB Service │  │ Notification │
                    →    │   (Go/REST)  │  │ (Node.js/WS) │
                         └──────────────┘  └──────────────┘
                              ↕ gRPC / Kafka ↕
                         ┌──────────────────────┐
                         │    API Gateway        │
                         │  (Auth, Rate Limit)   │
                         └──────────────────────┘

🏗️ Architecture Diagram — Strangler Fig Migration Path

Current State → Target State

Strangler Fig Migration Sequence

Migration Pattern Detail — Step by Step

Step 1: Facade / API Gateway

Deploy API Gateway di depan monolith. Semua traffic route through gateway. Monolith masih handle semua request.

Client ──→ [API Gateway] ──→ [PHP Monolith]

Step 2: Extract + Route

Extract Auth Service ke Go microservice. Gateway route /auth/* ke service baru, sisanya ke monolith.

Client ──→ [API Gateway] ──┬→ [Auth Service] ✅
                           └→ [PHP Monolith]

Step 3: Repeat per Domain

Extract Payment, KRS, Notification satu per satu. Setiap service punya DB sendiri (bounded context). Kafka event bus untuk cross-service communication.

Client ──→ [API Gateway] ──┬→ [Auth Service] ✅
                           ├→ [Payment Svc] ✅
                           ├→ [KRS Service] ✅
                           ├→ [Notif Svc] ✅
                           └→ [PHP Monolith] 🔻
                               (shrinking)

Step 4: Decommission Monolith

Monolith hanya serve legacy endpoints. Eventually fully replaced. Zero-downtime throughout whole process!