REQUIRES AN ACTIVE/EXISTING TS/SCI WITH CI POLYGRAPH DAn Solutions is seeking experienced Systems Software Engineers with strong systems programming and database engineering backgrounds to support a mission-critical federal government program.This position focuses on understanding and modifying how database engines and core software services operate internally. The ideal candidate is comfortable analyzing source code, examining network communications, tracing application behavior, and developing secure, scalable solutions across integrated technology environments.Key ResponsibilitiesDevelop, test, maintain, and deploy software using C, C++, Rust, Go, Java, Python, or Node.js.Develop concurrent and multithreaded applications using systems programming principles.Analyze database engine source code, communication protocols, serialization formats, and packet structures.Design and troubleshoot networked applications using sockets and client-server architectures.Develop relational and graph database solutions, including SQL optimization and performance tuning.Support technologies such as PostgreSQL, Redis, Neo4j, Amazon S3, and Elasticsearch.Modernize existing services and develop Infrastructure as Code (IaC).Deploy and troubleshoot cloud-hosted applications and supporting infrastructure.Integrate identity services using OpenID Connect (OIDC), authentication, authorization, and Zero Trust principles.Maintain technical documentation, software designs, and operational procedures.Required QualificationsActive TS/SCI clearance with the ability to obtain a CI Polygraph.Bachelor's degree in Computer Science, Engineering, Information Technology, Mathematics, or a related quantitative discipline.Typically 10 years of professional software engineering experience.Previous Intelligence Community experience.Hands-on systems programming experience with C, C++, or Rust.Experience with operating-system interfaces, process management, concurrency, and multithreaded applications.Experience analyzing database internals, network protocols, or low-level software behavior.Strong SQL, relational database, and graph database knowledge.Experience with cloud infrastructure, automation, and identity integration using OIDC.Knowledge of Zero Trust Architecture and enterprise security controls.Experience with Agile, DevOps, or DevSecOps methodologies.Agile Developer or Certified Scrum Developer certification.CompTIA Security+ or higher cybersecurity certification.Preferred QualificationsMaster's degree in a related technical discipline.Experience with PostgreSQL, Neo4j, and database engine internals.Terraform, Ansible, AWS GovCloud, Kubernetes, or Red Hat OpenShift.Experience with PingFederate, Keycloak, SailPoint, Okta, or similar identity platforms.Experience with PKI, cryptographic integrations, Hardware Security Modules, or PKCS #11.Familiarity with Trusted Data Format, Protocol Buffers, and modern cryptographic technologies. Work LocationThis position requires full-time work at a government facility in Charleston, SC or the Washington Metropolitan Area. Candidates in other locations may be considered. Salary Range Disclaimer:The posted salary range represents the good-faith minimum and maximum compensation DAn Solutions expects to pay for this position. The position may be filled at different Labor Category (LCAT) levels depending on the selected candidate's qualifications and applicable contract requirements. Final compensation within the posted range will be determined based on the applicable LCAT and factors including education, relevant experience, certifications, and other required qualifications