# Kamil Çalışkan — Backend Software Engineer

Backend-focused developer building secure, reliable, and production-ready APIs.  
Based in Baden-Württemberg, Germany. Open to junior backend roles.

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## Core Skills

**Backend:** Java 17, Spring Boot 3, REST APIs, JWT, Role-based access  
**Database:** PostgreSQL, JPA/Hibernate, Flyway, Transactions  
**Testing:** JUnit 5, Mockito, Testcontainers  
**DevOps:** Docker, Docker Compose, GitHub Actions (CI/CD)

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## Projects

### Secure Transaction Ledger API
Backend system simulating financial transactions.

- Atomic transfers with rollback  
- Pessimistic & optimistic locking  
- JWT authentication & authorization  
- Audit logging  
- Integration tests with PostgreSQL (Testcontainers)  
- Dockerized with CI/CD  

**Tech:** Spring Boot, PostgreSQL, Flyway, JWT, Docker  

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## Other Projects

- **WoW Battle Royale (C++)** — Game logic & backend basics  
- **Job Tracker Dashboard (JavaScript)** — Simple tracking UI  

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## Engineering Focus

- Clean API design  
- Secure coding practices  
- Reliable database handling  
- Test-driven development basics  

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## Languages

Turkish (Native)  
English (B2)  
German (B1)