Custom Software Systems, Inc. (CSS) is seeking a highly skilled Software Engineer to architect, build, and maintain enterprise-scale applications using modern Java technologies and event-driven design principles. This role is ideal for a technically strong engineer with hands-on experience in Spring Boot microservices, message-broker integration, and modern front-end development, who can translate complex requirements into scalable, maintainable software solutions within a secure, containerized environment.
Responsibilities
- Collaborate with cross-functional teams to architect, design, and implement enterprise software solutions.
- Apply event-driven architecture principles to develop scalable, resilient, and loosely coupled applications.
- Develop microservices using Spring Boot and associated Spring frameworks.
- Build response and maintainable user interfaces using React.
- Provide strong technical expertise in PrimeFaces 6.0 and above, including component usage, customization, and integration within Java Server Faces (JSF) applications.
- Implement message queuing and event streaming using RabbitMQ.
- When experience is based on Kafka, demonstrate understanding of architectural and operational differences between Kafka and RabbitMQ.
- Develop message producers, consumers, routing logic, and related integration components.
- Deploy microservices to Kubernetes clusters using automated CI/CD pipelines.
- Monitor, diagnose, and troubleshoot production systems to ensure reliability and uptime.
- Perform performance tuning and scalability optimization across application and infrastructure layers.
- Write unit tests with a target of 85% or greater code coverage.
- Participate in peer code reviews to enforce coding standards and best practices.
- Conduct system testing, debugging, and validation activities.
- Prepare technical specifications, architecture documentation, and design decision records.
- Produce sequence diagrams for major use cases as part of design deliverables.
- Collaborate with product managers, designers, and engineering teams to refine requirements and ensure alignment on deliverables.
- Reporting Requirements (in a JIS prescribed format)
- Submit weekly activity reports to summarize progress on assigned programs and projects.
- Provide weekly project status reports in the JIS-prescribed format.
- Complete weekly time reporting using JIS-provided forms, along with any additional reports requested by the supervising manager.
- Apply event-driven architecture (EDA) principles to design scalable and resilient systems.
- Demonstrate high-level Java competency, including strong understanding of core libraries, concurrency, collections, JVM fundamentals, and modern Java features.
- Analyze complex technical challenges and propose effective, maintainable solutions.
- Develop and maintain applications using PrimeFaces 6.x and above, including component customization and JSF integration.
- Produce clean, maintainable, and testable code aligned with industry best practices.
- Collaborate effectively within Agile or hybrid development teams.
Clearance
- Must be clearable.
Citizenship
- US Citizenship
Required Qualifications
- Core Java: 8+ years of high-level competency (concurrency, JVM fundamentals, modern Java features).
- Backend Frameworks: 4+ years of development using Spring Boot and associated frameworks.
- Frontend Development: 4+ years building responsive interfaces utilizing React and/or Angular.
- Messaging & Streaming: 4+ years implementing message queuing and event streaming using RabbitMQ or Kafka.
- Must have three (3) years of experience as a software engineer.
- Specialized Experience: At least two (2) years of experience working with Ada, SQL, or third/fourth generation languages in the design and implementation of systems.
- One (1) year working with DBMS
Education
- A Bachelor's Degree from an accredited college or university with a major in Computer Science, Information Systems, Engineering, Business, or other related scientific or technical discipline, or three (3) years of equivalent experience in a related field.
Knowledge, Skills & Abilities
- Data & Security: Experience with RESTful APIs, secure coding principles, and both Relational/NoSQL database.
- Infrastructure: Proficiency with Kubernetes, Docker, and CI/CD pipelines.
- Legacy Integration: Ability to maintain applications using PrimeFaces 6.x and JSF.
- Architecture: Knowledge of design patterns and Event-Driven Architecture (EDA).
Preferred Qualifications
- Modern front-end development using React and/or Angular for building responsive, component-based user interfaces.
- Message-queuing and event-streaming technologies, including RabbitMQ or Kafka, for distributed system communication.
- Elasticsearch for indexing, search, and analytics (preferred but not mandatory).
- Microservices development using Spring Boot or equivalent Java frameworks.
- Cloud platforms such as AWS, Azure, or Google Cloud for deployment, monitoring,
- and scaling (preferred but not required).
- DevOps and source control tools, including Git, CI/CD pipelines, and automated
- build processes.
- Software design patterns and architectural best practices, with the ability to apply them appropriately.
- Containerization and orchestration techniques, including Kubernetes and Docker.
- RESTful API design, web services, and integration patterns.
- Relational and NoSQL databases, such as PostgreSQL, MySQL, MongoDB, or Cassandra.
- Application performance tuning, monitoring, and observability tools (e.g., Prometheus, Grafana, ELK stack).
- Security best practices, including authentication, authorization, and secure coding principles
Top Skills
What We Do
Welcome To Custom Software Systems, Inc.
About Custom Software Systems, Inc.:
Headquartered in Leesburg, Virginia, Custom Software Systems, Inc. (CSS) is a certified Woman Owned Small Business (WOSB) and certified HUBZone Business. Built on a foundation of trusted client partnerships, CSS has fostered a “stakeholder-centric”, yet disciplined approach to IT solutions development. This ensures our ability to consistently deliver on time and within budget and to meet or exceed our customers’ expectations.
Core Expertise:
CSS specializes in developing and implementing Custom Software Solutions and Support Services which deliver high value to our customers. Our skilled team of consultants helps our clients/partners integrate technology that fits their business needs. We provide our clients with a full array of services, including:
- Project Management & Oversight (PMP certified Project Managers)
- Database and Data Management (Certified DBA’s)
- Data Architecture (DAMA and TDWI member)
- Middleware Support (Oracle Fusion Middleware)
- Application Lifecycle Management (ALM)
- Oracle Fusion Middleware Support
- Business Intelligence Support (WebFOCUS, Business Objects, Tableau)
- Full Lifecycle Application Development (Agile, RUP, Waterfall)
- Identity Management
- Operations and Maintenance
Core Values:
CSS was founded on a set of guiding principles that include good old fashioned hard work, ethics, teamwork, and innovation. We establish relationships with our customers that are based on direct and honest communication and perseverance to get the job done which in turn fosters respect and trust. We expect our associates, at every level, to conduct themselves with integrity, honesty and strong ethics in all relationships with customers and employees.








