Senior Software Engineer

About Us

Sealing Technologies, a Parsons company, innovates and delivers high-performance deployable anywhere technologies that push what's possible at the edge, enabling organizations across the globe to solve complex challenges with speed and confidence. We design, engineer, and deliver products and deployable technologies built for environments where traditional infrastructure falls short.

Position Overview

SealingTech is looking for a talented and experienced Senior Software Engineer to join our dynamic team of engineers delivering cutting-edge solutions. You will take ownership of existing web products and continue active development across frontend, backend, and deployment workflows. You will own your technical approach and help shape the big picture.

This is an opportunity to work on real-world challenges, supporting mission-critical applications. Collaboration and innovation are crucial in this role, requiring a proactive approach to problem-solving and continuous learning. You will be stepping into a live codebase and be expected to ship features, maintain reliability, and handle production issues.

Duties and Responsibilities:

• Design and architect solutions for the Zepharis product suite and its existing integrations
• Troubleshoot and resolve issues across local, CI, and production environments.
• Co-lead day-to-day development of the Zepharis product suite; UI, API, and database layers; alongside senior engineering leadership.
• Build new features as a full-stack engineer using Python, React, FastAPI, Pydantic, SQLAlchemy, and Postgres.
• Architect database schema changes and plan migrations.
• Document technical decisions to improve handoff and operational clarity.
• Mentor junior/mid-level engineers and lead code reviews or design discussions.

Minimum Qualifications:

• U.S. Citizenship.
• 8+ years of software engineering experience.
• SME level experience in React or Vue, and TypeScript.
• Experience working with CSS frameworks and UI component libraries (e.g., Bootstrap, Tailwind CSS, BaseUI, etc.)
• Experience with frontend state management (e.g., TanStack Query, Redux) and component testing frameworks (e.g., Vitest, Jest, Cypress, or Playwright).
• SME level Python backend development with at least one web framework (e.g., FastAPI, Django, Flask).
• Experience with PostgreSQL, including Alembic migrations.
• Experience with Server-Sent Events or WebSockets for streaming updates.
• Practical experience with Docker/Podman and compose-based development.
• Experience with Git/GitHub, CI/CD pipelines (e.g., GitHub Actions, Argo CD), and Agile workflows (Jira).
• Built and shipped enterprise web applications.
• Strong written and verbal communication skills, with the ability to document and maintain engineering processes and procedures.
• Bachelor's degree in Engineering, Computer Science, Information Technology, or related field; equivalent experience will be considered.
• Comfortable working in a Linux development environment.

Preferred Qualifications:

• RAG and LLM Context Engineering solution architecture experience
• Experience with LLM inference engines such as vLLM
• Experience using AI coding assistants (e.g., Claude Code, GitHub Copilot) to accelerate feature development, refactoring, and test creation.
• Comfortable integrating AI-assisted workflows into test automation and QA processes to improve coverage and catch regressions.
• Experience with Fedora-based Linux distributions (RHEL, Rocky, Oracle).
• Experience with Ansible-based deployment workflows.
• Experience with cyber tooling and ecosystems (e.g., Elasticsearch/Opensearch, Kibana, Splunk, or similar SIEM/log-analytics platforms)
• Experience supporting Defensive Cyber Operations within Service Cyber Command elements or other U.S. Government organizations.