Front End developer

JavaScript / Front-End Developer

Job Summary

We are seeking a skilled JavaScript/Front-End Developer to support a major modernization initiative transforming a 40-year-old mainframe application into a modern, cloud-based user interface. The developer will help convert 750 legacy screens into responsive, accessible UI compatible with modernization tools that interface with COBOL and a C#/.NET backend.

The ideal candidate is an expert in modern JavaScript frameworks, understands how to collaborate within a time-boxed modernization schedule, and is comfortable working closely with UI/UX designers, backend engineers, and stakeholders.

Responsibilities

• Develop modern, responsive front-end components that replace legacy mainframe interfaces.

• Translate UI/UX design artifacts (wireframes, prototypes, design system specs) into high-quality front-end code.

• Implement reusable components aligned with the program’s design system and modernization tool constraints.

• Ensure front-end code integrates cleanly with C#/.NET APIs and works within COBOL-interop modernization platforms.

• Work with UI/UX and backend teams to estimate workload, define sprint objectives, and maintain an achievable modernization cadence.

• Participate in PI Planning, Sprint Planning, Refinement, and Demos within an Agile SAFe environment.

• Identify modernization challenges early and collaborate on solutions (performance, data handling, state management, rendering issues).

• Conduct code reviews, ensure coding standards, and maintain version control across the modernization effort.

• Optimize front-end performance for users transitioning from legacy terminal workflows.

• Produce documentation for components, workflows, and integration patterns.

Required Abilities / Experience

• 5+ years of professional JavaScript/Front-End development experience.

• Advanced proficiency with at least one modern framework: React, Angular, Vue, Svelte, or equivalent.

• Strong experience with HTML5, CSS3, TypeScript, and component-driven UI architecture.

• Demonstrated success modernizing or rebuilding legacy applications, especially those with large-scale screen counts.

• Experience integrating front-end code with C#/.NET web APIs.

• Ability to interpret complex workflows and map them to modular, maintainable UI components.

• Experience working in Agile (Scrum or SAFe) teams, managing stories, estimates, and iterative releases.

• Strong debugging skills across browsers, devices, and data integration layers.

• Experience using Git or similar version control tools.

Desired Abilities / Experience

• Experience modernizing mainframe, COBOL-driven, or character-based legacy applications.

• Familiarity with cloud modernization patterns and API-first design.

• Experience using or integrating with UI modernization tools that output COBOL- or C#-compatible artifacts.

• Knowledge of DevSecOps workflows, CI/CD pipelines, automated testing, and artifact management.

• Experience working with large design systems or helping build reusable UI libraries.

• Understanding performance tuning for enterprise-scale front-end applications.

• Experience in government, defense, or highly regulated environments.