Informatics student, graduating soon with 197/240 ECTS from the University of Western Macedonia(THE World University Rankings: Computer Science: 601–800 for 2025). I work primarily in C and Java, with a focus on systems programming, network applications, and backend development. I am comfortable at the low level: sockets, process management, memory, file I/O. I also have experience building production structured backend applications with REST APIs, JWT security, role based access and database backends. Open to roles in systems, backend, or software engineering.  

ion-fusion/fusion-java (Amazon Ion): PR #490 · PR #518 · PR #521

• Fixed a bug in ActualSymbol.write() where operator symbols like + and = were incorrectly quoted inside sexp contexts, violating Ion spec behavior. Added test cases covering operator symbols, quoted symbols, null symbols, and improper sexps. Multi-round code review with project maintainers including a principal engineer with 20+ years at Amazon. 200+ lines accepted into main.
• Added ionize(Object, IonWriter) to the TopLevel public embedding API, placing ionization at the correct abstraction layer rather than FusionRuntime. Navigated package dependency constraints enforced by static analysis tooling, structural baseline maintenance, and Javadoc requirements for a public - facing interface. Reviewed and merged by Todd Jonker, co-inventor of Amazon Ion. 20+ lines accepted into main.
• Centralized FusionInterrupt exception handling in the embedding layer; introduced EvalTask<T> functional interface and withEvaluator() helper on StandardTopLevel, eliminating repeated boilerplate across all call sites and fixing a missing interrupt catch in StandardRuntime. 70+ lines accepted into main.

Greek Hospital Management Spring Boot REST API Java Spring Boot MySQL JWT Secure REST API for managing hospital patients, hospitalizations, and medical tests. Features stateless JWT authentication, role based access control (DOCTOR / CLERK / ADMIN) enforced at the HTTP method level, and atomic patient registration via Spring @Transactional. Includes a full Luhn algorithm implementation for validating Greek ΑΜΚΑ numbers with birth date extraction. Deployed on Railway!

api-gateway Python FastAPI Docker Redis High performing API Gateway for routing requests to backend services with resilience and control features. Includes rate limiting (Redis sliding window with Lua), retries with exponential backoff, circuit breaker (CLOSED/OPEN/HALF-OPEN), JWT authentication, tested to ensure security and response caching. Provides admin endpoints for monitoring (metrics, circuit states, rate limits) and a mock service for failure injection and testing.

Library-System-Java-MySQL Java MySQL Full library management system with SWING and MySQL backend. Features user authentication, book search, borrowed book tracking, and automated database initialization via SQL schemas.

process-supervisor Bash Docker Lightweight process supervisor written in Bash for managing and automatically restarting long running workloads in Docker and Kubernetes environments.

tcp-prime-factors-server-client C TCP client server application. The client sends integers over a socket; the server computes and returns their prime factors. Built for a networking course at UowM.

GitProjectServer C Winsock Multithreaded HTTP server written from scratch using Windows sockets. Handles concurrent connections without a framework.

currency-exchange-server C TCP/IP client server system for currency exchange operations. Focuses on protocol design and socket communication.

unix-process-management C Unix IPC Docker Demonstrates Unix interprocess communication using a shared pipe across multiple child processes. Covers the full process lifecycle: creation, concurrent execution, and synchronization via fork(), getpid(), pipe(), and wait(). Packaged with a multi stage Docker build; no local C toolchain required.

C Java Spring Boot Bash TCP/IP Unix MySQL Docker Kubernetes English C2 Michigan State University ECPE certified Git JWT REST APIs  

dalaklidesdemetres@gmail.com