Backend & Core Systems
* Java – The backbone of Amazon. Most core services (ordering, payments, logistics) are java based.
* C++ – Used where ultra-high performance and low latency matter.
* Python – Automation, data processing, ML pipelines, internal tools.
* Node.js – Some newer microservices and internal APIs.
Fun fact: Amazon standardized early on with Java + SOA, which later evolved into microservices.
Frontend & Client Apps
* React – Web UI (especially newer experiences).
* Angular (legacy areas) – Some internal tools.
* HTML, CSS, JS – Core web stack.
* Mobile
    * Java/Kotlin – Android
    * Swift/Objective-C – iOS
Cloud & Infrastructure
* AWS (obviously) – Amazon literally runs on its own cloud.
    * EC2, S3,DynamoDB, RDS, Lambda, ECS/KS
* Microservices architecture
* Containerization – Docker
* Orchestration – Kubernetes(EKS)
* Infrastructure as Code –
Database & Storage
* DynamoDB – Massive scale, low-latency NoSQL
* Aurora (MySQL/PostgreSQL compatible)
* S3 – Object storage at insane scale
* Redshift – Analytics & data warehousing
* Elasticache (Redis/Memcached – Caching
Messaging & Streaming
SQS – Queue-based communication
SNS – Pub/Sub
Kinesis – Real-time data streaming
Kafka – Used in some data pipeline
Data, AI & ML
* Python + PyTorch / TensorFlow
* Amazon SageMaker
* ML used for
    Recommendations
    Search ranking
    Fraud detection
    Demand forecasting
    Alexa (NLP + speech)
Security & Releability
* IAM – Fine-grained access control
* Internal security frameworks
* Encryption everywhere (at rest & in transit)
* Chaos Engineering – Systems are designed to fail safely
DevOps & Engineering Culture
* CI/CD pipelines (internal + AWS tools)
* Monitoring – CloudWatch, internal dashboards
* Two-Pizza Teams – Small, independent teams owning services
* API-first culture – Everything talks via APIs
Architecture Philosophy (Very Amazon)
* Microservices over monoliths
* “You build it, you run it”
* Extreme automation
* Design for millions of requests per second
TL; DR
Java + AWS + Microservices + DynamoDB + S3 + React + Heavy Automation
