Java Backend Developer

Company Name – Wissen Technology

Group of companies in India – Wissen Technology & Wissen Infotech

Work Location - Senior Backend Developer – Java (with Python Exposure)- Mumbai

Experience - 4 to 10 years

Kindly revert over mail if you are interested.

Java Developer – Job Description

We are seeking a Senior Backend Developer with strong expertise in Java (Spring Boot) and working knowledge of Python. In this role, Java will be your primary development language, with Python used for scripting, automation, or selected service modules. You’ll be part of a collaborative backend team building scalable and high-performance systems.

Key Responsibilities

• Design and develop robust backend services and APIs primarily using Java (Spring Boot)
• Contribute to Python-based components where needed for automation, scripting, or lightweight services
• Build, integrate, and optimize RESTful APIs and microservices
• Work with relational and NoSQL databases
• Write unit and integration tests (JUnit, PyTest)
• Collaborate closely with DevOps, QA, and product teams
• Participate in architecture reviews and design discussions
• Help maintain code quality, organization, and automation

Required Skills & Qualifications

• 4 to 10 years of hands-on Java development experience
• Strong experience with Spring Boot, JPA/Hibernate, and REST APIs
• At least 1–2 years of hands-on experience with Python (e.g., for scripting, automation, or small services)
• Familiarity with Python frameworks like Flask or FastAPI is a plus
• Experience with SQL/NoSQL databases (e.g., PostgreSQL, MongoDB)
• Good understanding of OOP, design patterns, and software engineering best practices
• Familiarity with Docker, Git, and CI/CD pipelines

Job Title: Senior Linux Kernel Engineer

Experience: 5–10 Years

Location: Bangalore / Chennai

Domain: Enterprise Linux / Kernel Development

Job Summary

We are seeking a highly skilled Senior Linux Kernel Engineer with deep expertise in kernel development, debugging, and performance optimization. The role involves working on enterprise-grade Linux distributions, kernel lifecycle management, security patching, and low-level hardware integration.

Key Responsibilities

1. Kernel Lifecycle & Maintenance

• Lead kernel upgrade strategies (e.g., LTS migrations such as 5.15 → 6.x) while ensuring stability and compatibility.
• Perform patch porting across kernel versions, resolving API and dependency conflicts.
• Track and mitigate security vulnerabilities by monitoring CVEs and upstream sources (e.g., LKML).
• Backport critical fixes to production kernels without impacting system stability.

2. Debugging & System Stability

• Act as an escalation point for kernel panics and system crashes.
• Perform post-mortem analysis using kdump, crash, and gdb.
• Debug early boot issues (UEFI, initramfs, kernel initialization).
• Conduct performance analysis using eBPF, ftrace, and perf to optimize system behavior.

3. Driver Development & Hardware Integration

• Design, develop, and maintain device drivers (network, storage, GPU, or character devices).
• Work closely with hardware through DMA, interrupts (MSI-X), and register-level programming.
• Maintain out-of-tree drivers using DKMS or similar frameworks.
• Ensure compatibility of drivers across kernel updates.

Required Technical Skills

• Programming: Strong expertise in C (mandatory) and C++
• Kernel Internals: Deep understanding of:
• Virtual File System (VFS)
• Memory Management (MMU, Paging)
• Process Scheduler
• Linux Networking Stack
• Debugging Tools:
• kdump, crash, gdb
• kprobes, trace-cmd, ftrace
• perf, valgrind
• Hardware debugging tools (JTAG, Serial Console)
• Build Systems:
• Kbuild, Makefiles
• Kernel packaging (RPM/Debian)
• Security:
• Experience with CVE patching and backporting
• Knowledge of SELinux/AppArmor
• Kernel hardening (FIPS, KSPP)

Preferred Skills

• Experience contributing to open-source kernel projects
• Familiarity with Linux Kernel Mailing List (LKML) workflows
• Exposure to enterprise Linux distributions (RHEL, Ubuntu, SUSE)
• Experience with performance tuning and system optimization at scale

1. Core Programming (C Language)

• Must have strong hands-on experience in C programming
• Comfortable with pointers, memory management, and low-level concepts

2. Kernel Internals Expertise

• Should have worked in at least one subsystem:
• VFS / File Systems
• Memory Management
• Scheduler / Networking

3. Debugging & Crash Analysis

• Experience handling kernel panics
• Hands-on with vmcore analysis tools

4. Security & Patching

• Understanding of CVE fixes and backporting

5. Driver Development

• Experience in writing or maintaining device drivers

6. Performance & Advanced Debugging

• Exposure to eBPF, ftrace, perf

7. Hardware-Level Understanding

• Knowledge of DMA, interrupts, hardware interaction

Soft Skills

• Strong analytical and problem-solving abilities
• Excellent communication skills
• Ability to work independently and in collaborative environments
• Quick learner with adaptability to new technologies

Job Title: Java Developer 

Experience: 4 –10 Years 

Location: Mumbai / Bangalore 

Employment Type: Full-time 

We are looking for experienced and passionate Java Developers with strong expertise in Core Java, multithreading, and performance tuning. You will be responsible for designing and developing high-performance, scalable, and resilient backend systems. This is an exciting opportunity to work on complex, enterprise-level systems and modern architectures like microservices and event-driven frameworks.

 • 3–10 years of hands-on experience in Java (8 or above) development. 

 • Strong foundation in OOPs, data structures, algorithms, and design patterns.

 • Deep understanding of multithreading, concurrency, and synchronization techniques.

 • Experience with Spring Boot, Spring MVC, JPA/Hibernate. 

 • Good working knowledge of RESTful API development. 

 • Proficient in SQL and experience with relational databases like MySQL, PostgreSQL, etc.

 • Familiarity with Git, Maven/Gradle, and CI/CD pipelines. 

 • Exposure to Agile/Scrum methodology

About the Role

We are seeking a passionate and skilled Java + Kotlin Developer to join our growing engineering team. You’ll be responsible for building scalable backend systems and modern Kotlin-based applications, with opportunities to work on both Android and server-side development.

What You'll Do

• Develop and maintain robust backend services using Java and Spring Boot
• Design and implement modern applications using Kotlin (Android or Multiplatform)
• Work on APIs, microservices, and system integrations
• Collaborate with cross-functional teams in an Agile environment
• Write clean, maintainable, and testable code

Key Requirements

• 3+ years of hands-on experience with Java and Kotlin
• Strong grasp of Spring Boot, REST APIs, and microservices architecture
• Experience with Android Development or Kotlin on JVM
• Familiar with Git, Gradle, and CI/CD tools
• Bonus: Experience with Jetpack Compose, Kotlin Coroutines, or Kotlin Multiplatform

Good to Have

• Familiarity with cloud platforms like AWS / GCP
• Knowledge of Docker, Kubernetes, or DevOps practices
• Previous experience in a startup or fast-paced product environment

The ideal candidate should be a self-motivated, multi-tasker, and demonstrated team player. You will be responsible for the production support of software products and coordinating with various teams for support. You should have outstanding communication and Team-Player skills.

Educational Qualification: BCA, MCA or BE/B.Tech (CS)

Must-know technologies: Java,
Good to know technologies: DMN tools
Experience: 02 Years - 05 Years
Skill Level: Good

Responsibilities:

• Contribute to Java development work as well as the latest Decision model and notation tools

   

• Comply with coding standards and directions given by his direct manager Collaborate with an international and diverse team of Data Architects, Business Analysts, and Project Managers

• Tasks will be assigned and after completion, code need to be committed and task assigned for review by Senior Java developer

• Work with technology stakeholders to devise solutions that will fulfill business requirements and meet organizational strategic goals

• Develop application functionality which meets business requirements with high quality within given deadlines - develop maintainable, well-documented application functionality with an eye toward standardization, common components, simplicity, performance, robustness and other attributes of enterprise-strength solutions

• Thoroughly test all functionality - utilize detailed and thorough practices including negative testing, testing of boundary conditions, , and work collaboratively with business areas.

• Support interfaces between the deployment of developed applications and the decommissioning of legacy applications

• Support with the Development and Infrastructure Teams

• Design, and develop scalable, high-performance, highly reliable and secure applications using waterfall and agile methodologies

• Create reusable code

• 4 to 6 years plus experience in having implemented Hybris Commerce Solution.
• Working experience in Java, Spring, and Hibernate is a must
• Working experience of customizing Hybris Accelerators
• Proficient in Hybris core concepts and commerce concepts including, but not limited to, Hybris PCM Data Modeling, Endeca/SOLR, WCMS/ Customer Experience Manager, Cockpits, Cron jobs, internationalization, personalization, security concepts, and REST.
• Proficient in the catalog, order management, promotions, B2B commerce.
• Should have experience in handling multi/Omni-channel architecture through related Hybris Channel management modules.
• Good understanding of integration patterns/methodologies of Hybris with Organic SEO Search, Faceted Search, and Commerce Search.
• Should have exposure on the continuous integration build tools and code quality tools
• Working experience of Integration with external services such as payment gateways, Order management solution using Web services such as REST and SOAP
• Working experience of SOLR Search Engine is a plus

It is India’s only B2B Construction Materials Supply Chain Company. Construction & Infrastructure is  one of the industries, with the most complex problems in Supply Chain and we are fundamentally reengineering the  way construction materials get procured. Our Clients include the biggest names in India & the World– The  LafargeHolcim Group, JSW Group, The Tatas and many others. We are backed by some of the world’s top marquee  funds in our journey to create transparency and standardization to an otherwise opaque industry. 

Your responsibilities: 

• Understand the business context and build high quality code using proven design patterns Develop, test and deploy integrations required to meet business requirements 
• Carry out unit tests and other quality control mechanisms to inform and validate the code and design 
• Utilizing and monitoring cloud infrastructure resources (such as AWS, Azure) efficiently 
• Participate in a highly fluid environment applying agile software development principles 
• Ensure the coding standards are on-par with the best in the industry 

Educational Qualifications: 

• Bachelor's or Master’s degree in a quantitative field (e.g. Mathematics, Engineering, Computer Science).  

Must have skills: 

• 3+ years of work experience with mobile/web development 
• Experience in working with either of languages: Go, Java, Scala 
• Strong understanding of relational and non-relational databases (MySQL, PostgreSQL, MongoDB, Cassandra) 
• Strong understanding of Message brokers 
• Must have hands on experience in Restful APIs 
• Must have a strong foundation of Data structures and Algorithms 
• Using logic and reasoning to identify the strengths and weaknesses of alternative solutions, conclusions or approaches to problems 
• Ability to deploy features on a daily basis: should be good at time management and prioritization 
• Hands-on experience in CI/CD principles and TDD 
• Strong written and verbal English communication skills 

Good to have skills: 

• Experience in event-driven & asynchronous I/O frameworks 
• Exposure to business process and workflow automation 
• Working experience in process driven and data intensive business applications 
• Experience in working on web infrastructure with React.js and React Native 

Professional traits: 

• Self-motivated, persistent and “Never Give Up” attitude 
• Passion for innovation and adaptability to a lean startup culture 
• Ability to work with minimal supervision, independently and / or as a member of a team 
• Giving full attention to what other people are saying, taking time to understand the points being made,  asking questions as appropriate