Java Developer

Job Summary

We're looking for a Senior Backend Software Development Engineer (SDE 2 and SDE 3) with deep technical expertise in building and operating production systems at scale. You'll own entire components/services within microservices and data pipelines that handle ~200K queries per second and process petabytes of data daily. This role demands hands-on coding excellence, strong Low-Level Design (LLD) skills, and complete ownership—from component architecture through infrastructure management to cost optimization. You'll architect solutions, lead technical decisions, and drive operational excellence while shipping code daily.

Key Responsibilities:

• Component Ownership: Own one or more critical components/services end-to-end—responsible for architecture, development, deployment, operations, and evolution
• Technical Ownership: Own the entire lifecycle of your components—design, implementation, testing, deployment, monitoring, incident response, and continuous improvement
• Low-Level Design: Create detailed technical designs (LLD) for complex systems—defining data models, APIs, concurrency patterns, and failure modes
• Hands-on Development: Write production-grade code daily—this is not a purely architectural role; you'll be deep in the codebase
• Infrastructure Ownership: Own and operate the infrastructure your components run on—capacity planning, scaling, reliability improvements
• Cost Management: Drive cost optimization for owned components—analyze spending, identify waste, implement efficient architectures
• Scale & Performance: Build and optimize systems handling 200K+ QPS and petabyte-scale data processing
• Observability: Design and implement comprehensive monitoring, alerting, and debugging capabilities for owned components
• Incident Leadership: Lead incident response for your components and related services, conduct post-mortems, drive systemic improvements
• On-Call Excellence: Participate in on-call rotations and ensure your components are operationally sound (runbooks, alerts, dashboards)
• Technical Roadmap: Define and drive the technical roadmap for your owned components—balancing feature development, tech debt, and operational improvements
• Technical Mentorship: Guide junior and mid-level engineers on system design, code quality, and production best practices
• Cross-functional Collaboration: Work with product, infra, and other eng teams to define requirements and deliver solutions
• Agile Execution: Break down complex projects, deliver incrementally in daily cadence, iterate based on feedback

Required Qualifications:

• Experience: 2+ years building and operating backend systems in production environments at scale
• Education: B.E./B.Tech in Computer Science or equivalent practical experience
• Component Ownership: Proven track record of owning significant components or services from inception to maturity—demonstrable end-to-end ownership
• Low-Level Design (LLD): Proven ability to create detailed technical designs—data structures, algorithms, API contracts, concurrency models, failure handling
• Programming Mastery: Expert-level proficiency in at least one modern language (Go, Python, Java, NodeJS etc.) with track record of writing maintainable, performant production code
• Databases: Deep hands-on experience with SQL and NoSQL databases—schema design, query optimization, indexing strategies, operational troubleshooting
• Microservices at Scale: Extensive experience building, deploying, and operating microservices handling high throughput and large data volumes
• Data Pipelines: Strong background designing and running data processing pipelines at scale (batch and/or streaming)
• Observability: Expert understanding of metrics, logging, tracing, and alerting—you know how to make systems debuggable
• Production Operations: Significant experience with incident response, on-call rotations, debugging live issues under pressure
• Infrastructure Knowledge: Hands-on experience managing infrastructure, understanding resource utilization, capacity planning
• Cost Consciousness: Experience analyzing and optimizing infrastructure costs at scale
• Distributed Systems: Strong fundamentals in distributed systems, concurrency, consistency models, and failure scenarios
• Accountability: Track record of taking full ownership—from design through deployment to ongoing operations and improvements

Preferred Qualifications:

• Experience with cloud platforms (GCP, AWS, or Azure) including cost management tools
• Kubernetes and container orchestration at scale
• Infrastructure as Code (Terraform, Pulumi, etc.)
• Streaming data systems (Kafka, Pub/Sub, Kinesis, Flink, etc.)
• SRE principles and reliability engineering practices
• Experience with FinOps or infrastructure cost optimization
• Performance profiling and optimization (CPU, memory, I/O)
• Technical leadership experience including mentorship of teams and driving multi-component initiatives
• Open source contributions or recognized technical writing

• Strong experience in Core Java, Multi-Threading, data structures (List/Map/Set) and unit testing
• with (Junit, Mockito)
•  Strong experience with Spring Framework (Spring MVC, Spring REST, Spring Data), ORM
• frameworks (JPA, Hibernate) and RDBMS (Oracle/MySQL/Postgres)
•  Strong experience in applying Object-Oriented design principles and Design Patterns
•  Good knowledge of Multi-Tier architecture, Micro Services architecture and Service Oriented
• Architecture 
•  Exposure to AWS Cloud, NoSQL Database (Mongo, Cassandra), Message Broker (Active
• MQ/RabbitMQ/Apache Kafka) and Big Data Technologies (Hadoop/Hive/Spark)
•  Additionally, must possess capability to review code, produce technical specification document
• and knowledge of code quality tools (PMD/FindBugs/Sonar)

Work Location - Bangalore (Should be ready to relocate)

Kindly go through the JD & company details if interested please revert with below details & acknowledge with your availability.

Mode of work: Hybrid weekly 2/3 Times Mumbai/ Bangalore location.

While you may already know about Wissen and the company history, here is a quick rundown for you.

INTERVIEW PROCESS:

1. Hacker earth assessment
2. Round 1
3. Round 2
4. Final Round

About Wissen Technology:

• The Wissen Group was founded in the year 2000. Wissen Technology, a part of Wissen Group, was established in the year 2015.

• Wissen Technology is a specialized technology company that delivers high-end consulting for organizations in the Banking & Finance, Telecom, and Healthcare domains. We help clients build world class products.

• Our workforce consists of 550+ highly skilled professionals, with leadership and senior management executives who have graduated from Ivy League Universities like Wharton, MIT, IITs, IIMs, and NITs and with rich work experience in some of the biggest companies in the world.

• Wissen Technology has grown its revenues by 400% in these five years without any external funding or investments.

• Globally present with offices US, India, UK, Australia, Mexico, and Canada.

• We offer an array of services including Application Development, Artificial Intelligence & Machine Learning, Big Data & Analytics, Visualization & Business Intelligence, Robotic Process Automation, Cloud, Mobility, Agile & DevOps, Quality Assurance & Test Automation.

• Wissen Technology has been certified as a Great Place to Work®.

• Wissen Technology has been voted as the Top 20 AI/ML vendor by CIO Insider in 2020.

• Over the years, Wissen Group has successfully delivered $650 million worth of projects for more than 20 of the Fortune 500 companies.

We have served client across sectors like Banking, Telecom, Healthcare, Manufacturing, and Energy. They include likes of Morgan Stanley, MSCI, State Street, Flipkart, Swiggy, Trafigura, GE to name a few.

Website : www.wissen.com

Wissen Technology has been certified as a Great Place to Work®. The technology and thought leadership that the company commands in the industry is the direct result of the kind of people Wissen has been able to attract. Wissen is committed to providing them the best possible opportunities and careers, which extends to providing the best possible experience and value to our clients.

Job Description:

As per our conversation, please find below the job description for your review. 

·       Strong written/verbal communication skills

·       Minimum 4-14 Years of Core Java Programming with Collections Framework, Concurrent Programming, Multi-threading (Good knowledge in Executor service, Fork join pool and other threading concepts)

·       Good knowledge of the JVM with an understanding of performance and memory optimization.

·       Extensive and expert programming experience in JAVA programming language (strong OO skills preferred).

·       Excellent knowledge on collections like, Array List, Vector, LinkedList, HashMap, Hash Table, HashSet is mandate.

·       Exercised exemplary development practices including design specification, coding standards, unit testing, and code-reviews.

·       Expert level understanding of Object-Oriented Concepts and Data Structures

·       Good experience in Database (Sybase, Oracle, or SQL Server) like indexing (clustered, non clustered), hashing, segmenting, data types like clob / blob, views (materialized), replication, constraints, functions, triggers, procedures etc.

·       While you may already know about Wissen and the company history, here is a quick rundown for you.

Location: Mumbai, Maharashtra, India

Desired Experience: 3+ years

Roles and Responsibilities :

We are seeking an experienced Java Engineer to join our team. The ideal candidate will be responsible for designing and developing scalable applications using Java and related frameworks.

Core Accountabilities:

• Design and develop high-quality Java applications using best practices and design patterns Write clean, maintainable, and testable code using Java and related frameworks
• Collaborate with cross-functional teams to develop and deploy applications
• Develop and maintain continuous integration and continuous deployment pipelines using Git and related tools
• Troubleshoot and debug applications in production and development environments
• Stay up-to-date with emerging trends and technologies in software engineering and Java development

Experience required :

• Bachelor's degree in Computer Science or a related field
• 3+ years of experience in developing applications using Java and related frameworks
• Strong experience in Core Java, Spring Framework, Hibernate, and related Java frameworks
• Experience in working with Git for version control and collaboration.

Additional optional requirements

• Knowledge of AWS services
• Experience in working with NoSQL databases such as MongoDB and Cassandra
• Experience in other programming languages such as Python and Node.js

Skills required :

• Excellent problem-solving skills and ability to work in a fast-paced environment Strong communication and collaboration skills

Java

Mandatory:

1. Strong expertize in Java/J2EE(4-7 years of experience)
2. Strong  expertize in Microservices, SpringBoot
3. Java including multithreading and concurrency

Preferred skills :

1. Experience in  Virtualization, SDN, NFV, Yang, Netconf
2. Good Knowledge on Networking
3. Multithreading and concurrency

Professional Requirements:

• 2-8 Years professional development experience.
• Bachelor’s and/or Master’s degree, preferably in CS, or equivalent experience.
• Good understanding of data structures and algorithms.
• Good understanding of high level and low-level design of distributed systems.
• Experience coding in any one of the following Java or Nodejs.
• Experience building highly available distributed systems on cloud infrastructure will be plus.
• Exposure to architectural pattern of a large, high-scale web application.

Requirement/responsibilities: To take a project from scoping requirements through launch of the project. Ownership of product/feature end-to-end for all phases from the development to the production. Ensuring the developed features are scalable and highly available with no quality concerns. Work closely with senior engineers for refining the and implementation. Management and execution against project plans and delivery commitments. Participate in design and code reviews.

Job Summary:

• Willingness to work on highly scalable cloud-native solutions based on microservices.
• Quickly learn the technologies and deliver using the same.
• Take complete ownership of the customer requirements.
• Motivated to deliver world-class quality.
• Inclined to bring new ways of thinking, working and providing solutions.
• Drive the concept of quality into everybody and have a zero-tolerance towards bad quality.

• Understand requirements from product management, customer and able to comprehensively break this down to manageable tasks.

Experience:

● 3-9 years of development experience.

Technical Skills:

Mandatory:

• Java - Advanced concepts concurrency, reflection, lambda, Java Springboot, Spring security,
• Actuator/Prometheus/Grafana/Servo (metrics),
• EFK/ELK stack (log analysis)
• OpenAPI/Swagger (documentation)
• RDBMS (PostgreSQL, MySQL, Maria or any other)
• NoSQL (Anyone of Mongo DB, Redis, Cassandra, Neo4J or other DBs)
• Automated unit tests/e2e tests (JUnit, TestNG, RestAssured etc)
• CI/CD pipelines (Jenkins, Sonar, Maven/Gradle etc)

Optional: (But highly recommended)

• NewSQL DB (TiDB, CockroachDB)
• AMQP/RabbitMQ
• Kafka
• Docker
• Kubernetes