Senior Scala Software Engineer

The Technical Frontier As part of the Knowledge Exploitation & Decisions Systems Group, you will work at the intersection of AI and human decision-making. Our portfolio is diverse and high-impact, including Command & Control (C2) via intuitive human-machine interfaces that help operators make the best possible decisions in high-pressure environments, Trusted AI & Autonomy via simulation platforms to test AI autonomy and evaluating the reliability and responsibility of autonomous systems, and Advanced Reasoning via graph-based reasoning and evolutionary algorithms for resilient workflow optimization, and enhancing language models to assess the feasibility of scientific claims.

What You’ll Do:

• Build & Scale: Design and implement flexible microservices and high-performance APIs within a robust DevSecOps ecosystem, focused on resilient distributed computing at the tactical edge.
• Drive Deployment: Take technical ownership of features within a mature mission planning solution, guiding them through the critical transition from R&D into an active user community.
• Collaborate: Work closely with other scientists, engineers, and end users to translate mission requirements into production-grade, scalable software.
• Own Your Growth: Beyond your initial project, your trajectory will be driven by the intersection of your interests and our evolving R&D portfolio., * Hands on experience with CRDTs or conflict free replication (state-based, op-based or delta-state) and the join-semilattice model behind them.
• Familiarity with P2P / epidemic protocols: gossip, anti-entropy, SWIM-style failure detection, HyParView/Plumtree partial-view overlays, or Kademlia-style DHTs.
• Low-bandwidth set reconciliation and probabilistic datastructures: PinSketch/minisketch, IBLT, Merkle digests and comfort with the finite-field math underneath.
• Delay or disruption tolerant networking.
• Deterministic simulation testing and property-based testing.

Our Tech Stack:

• Primary: Scala 3 (LTS) on JDK 21+, typed functional programming with cats-core
• Infrastructure: Linux, Docker, Kubernetes, GitLab
• Observability: OpenTelemetry, slf4j / logback
• Secondary: Python (for AI/Data integration)

• Education: BS or MS in Computer Science or a related technical field.
• Experience: 3-5+ (BS) or 1-2+ (MS) years of professional experience building maintainable, well-documented APIs and software

• Clearance: U.S. Citizenship required with active DoD SECRET Clearance

• Technical Depth:
• Proven proficiency in Scala or strong fluency in another typed functional language. You have a strong grasp of functional programming and type-driven algebraic design (immutability, pure functions, type classes, functional core/ imperative shell) and a track record of building correct, maintainable, well documented software.
• You understand or are excited to master eventual consistency, replication, and reasoning about correctness under message loss, reordering, duplication, and partition. You reach for property-based tests and simulation to convince yourself something is right, not just examples.
• Independence: You are an self-directed contributor who can take a high-level requirement and turn it into a working technical implementation with minimal supervision.
• Mindset: You are a “trailblazer”-someone who is comfortable with ambiguity and loves learning new libraries and languages on the fly. We will be building foundational pieces from the group up, with rigorous testing.

3.73.7 out of 5 stars Arlington, VA Hybrid work $140,000 - $170,000 a year - Full-time

Do you want to build software that solves the world’s most complex national security problems? At STR, we don’t just write code; we bridge the gap between cutting-edge research and real-world mission success. You will join a multidisciplinary powerhouse of software engineers, physicists, mathematicians, and data scientists dedicated to taking innovative ideas from a whiteboard concept to a mature, deployed implementation., STR is a growing technology company with locations near Boston, MA, Arlington, VA, near Dayton, OH, Melbourne, FL, and Carlsbad, CA. We specialize in advanced research and development for defense, intelligence, and national security in: cyber; next generation sensors, radar, sonar, communications, and electronic warfare; and artificial intelligence algorithms and analytics to make sense of the complexity that is exploding around us.

STR is committed to creating a collaborative learning environment that supports deep technical understanding and recognizes the contributions and achievements of all team members. Our work is challenging, and we go home at night knowing that we pushed the envelope of technology and made the world safer.

STR is not just any company. Our people, culture, and attitude along with their unique set of skills, experiences, and perspectives put us on a trajectory to change the world. We can’t do it alone, though - we need fellow trailblazers. If you are one, join our team and help to keep our society safe! Visit us at www.str.us for more info., Pursuant to applicable federal law and regulations, positions at STR require employees to obtain national security clearances and satisfy the requirements for compliance with export control and other applicable laws.