Senior Full Stack Engineer

Job Type Full-time Description

About Us:

eSimplicity is a modern digital services company that partners with government agencies to improve the lives and protect the well-being of all Americans, from veterans and service members to children, families, and seniors. Our engineers, designers, and strategists cut through complexity to create intuitive products and services that equip federal agencies with solutions to courageously transform today for a better tomorrow.

Role Overview:
We’re looking for a seasoned Full Stack Developer who thrives at the intersection of modern web development and complex data systems. This role is ideal for someone eager to explore and build tools that help move, manage, and govern large-scale data across interconnected platforms. You’ll work on building web interfaces, backend services, and automated workflows that power our internal helper tools, support data mesh strategies, and manage authenticated access to distributed data environments.

You’ll be collaborating closely with engineers, DevOps, product owners, and data architects to rapidly prototype, build, and scale data-aware applications and infrastructure that facilitate secure and efficient data movement and integration.

Responsibilities:

• Design, develop, and maintain modern full-stack web applications that enable data flow and visibility across platforms.
• Prototype and operationalize tools that assist in large-scale data movement and ETL automation.
• Build APIs and backend services to authenticate, authorize, and connect with data mesh nodes.
• Integrate with enterprise and third-party data sources via secure and scalable interfaces.
• Collaborate with cross-functional teams in an Agile environment to gather requirements and deliver incremental improvements.
• Contribute to the design and implementation of secure access patterns across distributed data systems.
• Author technical documentation, including API specifications, deployment guides, and internal usage manuals.
• Participate in performance tuning and monitoring of deployed services, ensuring systems are observable and scalable.
• Help define and support CI/CD practices to ensure safe and reliable deployments.
• Participate in daily standups, sprint planning, demos, and retrospectives.

Requirements

• All candidates must pass public trust clearance through the U.S. Federal Government. This requires candidates to either be U.S. citizens or pass clearance through the Foreign National Government System which will require that candidates have lived within the United States for at least 3 out of the previous 5 years, have a valid and non-expired passport from their country of birth and appropriate VISA/work permit documentation.
• Minimum 7 years of relevant experience in software engineering.
• Bachelor's degree in Computer Science, Software Engineering, Data Science, Statistics, or related technical field.
• Proficiency in at least one of the following languages: TypeScript, JavaScript, Python.
• Strong experience with modern frameworks such as React.js, Next.js, Node.js, Flask.
• Proven experience working on large-scale system architectures and Petabyte-level data systems.
• Proficient in automated testing frameworks (PyTest, Jest, Cypress, Playwright) and testing best practices.
• Experience developing, testing, and securing RESTful and GraphQL APIs.
• Deep knowledge of working with relational and NoSQL databases (PostgreSQL, MySQL, MongoDB).
• Proven track record with AWS cloud architecture, including networking, security, and service orchestration.
• Experience with containerization and deployment using Docker, and infrastructure automation with Kubernetes and Terraform.
• Familiarity with Redis for caching or message queuing.
• Knowledge of performance monitoring tools like Grafana, Prometheus, and Sentry.
• Familiarity with Git, Git-based workflows, and release pipelines using GitHub Actions and CI/CD platforms.
• Comfortable working in a tightly integrated Agile team (15 or fewer people).
• Strong written and verbal communication skills, including the ability to explain technical concepts to non-technical stakeholders.

Desired Qualifications

• Experience working with authentication/authorization frameworks like OAuth, SAML, Okta, Active Directory, and AWS IAM (ABAC).
• Familiarity with data mesh principles, domain-oriented architectures and experience connecting data domains securely.
• Knowledge of event-driven architectures and systems like Kafka, Kinesis, RabbitMQ, or NATS.
• Experience exploring or building ETL pipelines and data ingestion workflows.
• Strong grasp of access control,