Senior Java Developer

Job Description:

We are looking for a Senior Java Developer with 3 years of experience for the Karachi office, specialised in backend systems, hardware integrations, and low-level network programming.

The ideal candidate must possess deep expertise in Java (17/21 ), Spring Boot, and Socket Programming (TCP/IP), with strong hands-on experience implementing

Modbus communication protocols (Modbus RTU / Modbus TCP) to interface with industrial hardware devices such as printers, cameras, and IoT sensors.

Key Responsibilities

• Designing high-throughput asynchronous I/O architectures (using Netty), writing optimized SQL queries with PostgreSQL/MySQL, managing ORM frameworks (JPA/Hibernate) and connection pooling (HikariCP), and integrating event-driven tools like Apache Kafka or Redis for real-time sensor data streaming.
• Strong skills in multithreading, concurrency control, system design, Docker containerization, Git version control, rigorous code reviews, and troubleshooting hardware communication latency are essential for this role.

Core Technical Skills:

• Strong knowledge of Core Java (Java 8 ) – OOP, Collections, Streams, Exception Handling, Multi-threading.
• Hands-on experience with Spring Boot – REST APIs, Spring Data JPA, Hibernate, validation, and exception handling.
• Experience in Spring Security (JWT authentication & authorisation).
• Knowledge of Socket programming / WebSockets for real-time communication.
• Experience with Microservices – service discovery, API gateway, configuration management.
• Proficiency in MySQL and PostgreSQL – database design, joins, indexing, and performance tuning.
• Hands-on with Cloud basics (Docker, CI/CD, cloud deployment).
• Familiar with communication between services (REST, Feign Client, RestTemplate, WebClient).
• Experience in UAT preparation – API documentation (OpenAPI), Postman collections.

Qualifications:

• Proficiency in Java and strong programming skills
• Experience in software development with a focus on designing and implementing scalable solutions
• Familiarity with the Spring Framework and expertise in developing applications using it
• Knowledge of microservices architecture and its implementation
• Strong analytical and problem-solving abilities
• Excellent teamwork and communication skills
• Bachelor’s degree in Computer Science, Information Technology, or a related field is preferred
• Prior experience with supply chain or factory automation systems is an advantage.