Software Engineer (Sustainment Software Engineer)

Castello Systems, Inc.; Corridor North (MD); On-site; USD 110,000 - 160,000; Full time

Job summary

Castello Systems, Inc. is seeking a hands-on software engineer to support a diverse portfolio of COTS and GOTS enterprise applications, spanning modern and legacy stacks.

You will work with Java, JavaScript, Oracle, and SQL, and will learn additional languages and frameworks as needed to support products and applications. Primary responsibilities include maintaining backend services, developing with JavaScript, and collaborating with customers and teams to deliver timely, secure solutions in a

Qualifications

• Hands-on software engineer familiar with enterprise apps across modern and legacy stacks.
• Experience building and supporting Java-based backend services with Spring Boot.
• Comfort with JavaScript, Oracle databases, and SQL; eagerness to learn new languages and frameworks.

Responsibilities

• Maintain, enhance, and modernize backend services written in Java and Spring Boot.
• Develop and troubleshoot software using JavaScript and other required languages.
• Work with Oracle databases and SQL to support data interactions.
• Learn new languages, frameworks, and tools as product needs evolve.
• Update dependencies to keep applications secure and maintainable.
• Analyze code changes from upgrades and perform root-cause analysis.
• Collaborate with customers, software developers, systems engineers, and stakeholders to deliver solutions.
• Participate in Agile ceremonies and sprint planning.
• Support deployments and operations in Linux and Docker environments.
• Contribute to long-term stability, reliability, and modernization of mission-critical applications.

Skills

Java

JavaScript

Oracle

SQL

Linux

Docker

Spring Boot

Maven

AWS

Angular

Git

GitLab

Node.JS

Tools

IDE/DevTools

SQL Tools

Job description

This position is ideal for a hands-on engineer who enjoys working across multiple technologies and technical disciplines. The selected candidate will support a diverse portfolio of Commercial Off-the-Shelf (COTS) and Government Off-the-Shelf (GOTS) enterprise applications utilizing both modern and legacy technology stacks. Responsibilities may include application development, system integration, application configuration and customization, cloud modernization, and production sustainment. Success in this role requires adaptability, strong technical problem-solving skills, and the ability to quickly learn new technologies as mission priorities evolve.

The ideal candidate is a versatile software developer with experience building and supporting enterprise applications. You should be comfortable working with Java, JavaScript, Oracle databases, and SQL, and have the aptitude and willingness to learn additional programming languages, frameworks, and technologies based on the needs of the products and applications you support.

Primary Responsibilities:

• Maintain, enhance, and modernize backend services developed using Java and Spring Boot.
• Develop, maintain, and troubleshoot software using JavaScript and other programming languages and technologies as required by the product.
• Work with Oracle databases and SQL to develop, troubleshoot, optimize, and support application data and database interactions.
• Learn and apply additional programming languages, frameworks, tools, and technologies as required by evolving application and mission needs.
• Update software requirements, libraries, frameworks, and dependencies to ensure applications remain secure, supported, and maintainable.
• Analyze and implement code changes resulting from dependency, framework, and technology upgrades.
• Perform application maintenance activities, including troubleshooting, root-cause analysis, issue identification, and defect resolution.
• Design and implement code enhancements and technical improvements based on customer, program, and operational requirements.
• Collaborate with customers, software developers, systems engineers, and other stakeholders to deliver timely and effective solutions.
• Participate in Agile ceremonies and contribute to sprint planning, estimation, technical discussions, and continuous improvement activities.

Support application deployments, troubleshooting, and operational activities within Linux and Docker-based environments.

Contribute to the long-term stability, reliability, security, performance, and modernization of mission-critical enterprise applications.

Technology Stack:

• Java
• JavaScript
• AWS
• MySQL
• Linux
• Maven
• SpringBoot
• Docker
• Angular
• Git
• GitLab
• Atlassian Tool Suite
• Oracle
• Node.JS
• Maven