Senior Software Engineer - Front End/Back End (Library of Congress)

Ad Hoc is a technology company that delivers scalable digital services using modern, agile methods. The Senior Software Engineer will design, develop, and deploy frontend or backend features, support cloud-native microservices, lead technical design efforts, resolve production issues, and mentor engineers while meeting program delivery requirements.

Responsibilities:

• Design, develop, and deploy high-quality features across frontend or backend systems within a cloud-native microservice architecture, with strong ownership of your area of the codebase
• Enforce engineering quality standards including mandatory peer code review, SonarQube quality gate compliance, and resolving security findings in-sprint rather than deferring them
• Build and consume RESTful APIs with versioned OpenAPI specifications, contributing to backend data integration logic using PostgreSQL and Elasticsearch or implementing user-facing features using Angular, HTML/CSS, and JavaScript
• Lead technical design discussions, author Architecture Decision Records, and present system diagrams and design documents to engineers, product owners, and federal stakeholders
• Diagnose and resolve production issues across systems you own, using incidents as opportunities to improve system resilience and inform team knowledge
• Actively mentor junior and mid-level engineers, providing code review feedback and guidance that builds technical capability across the team
• Contribute to CI/CD pipeline hygiene, infrastructure-as-code standards via Terraform, and GitLab pipeline optimization
• Participate in technical interviews and candidate evaluations
• May lead small, less critical, or temporary team structures and projects

Requirements:

• • 7+ years of relevant engineering experience and a Bachelor's degree, or equivalent additional experience in lieu of a degree
• • Must meet federal suitability requirements and pass a background investigation as a condition of employment
• • Expert-level proficiency in at least one of: frontend engineering (Angular, JavaScript, HTML/CSS) or backend engineering (Python, Java, PostgreSQL, Elasticsearch)
• • Strong working knowledge of containerized microservices and AWS services (ECS, RDS, S3, Lambda, CloudWatch)
• • Experience building and consuming versioned RESTful APIs with published OpenAPI specifications
• • Hands-on experience with CI/CD pipelines in GitLab and version control via Git
• • Working knowledge of WCAG 2.1 AA accessibility standards and their application to frontend or backend development
• • Strong written and verbal communication skills, able to translate technical decisions for non-technical audiences including federal agency stakeholders
• • Prior experience with federal agency digital services or government contracting environments
• • Experience with infrastructure-as-code using Terraform
• • Familiarity with event-driven architectures using AWS SNS/SQS and Lambda/Step Functions
• • Experience with consumer-driven contract testing using Pact or API contract governance across microservices
• • Exposure to SAFe or scaled Agile delivery frameworks including PI planning and ART coordination
• • Familiarity with third-party integrations such as Pay.gov, login.gov, or identity/authentication platforms
• • Experience mentoring engineers in a cross-functional federal delivery environment