Senior Scala Software Engineer

STR; Arlington (VA); Hybrid; USD 140,000 - 170,000; Full time

Job summary

STR is seeking a software engineer to build scalable microservices and high-performance APIs within a DevSecOps framework. You will collaborate with a multidisciplinary team across AI, data science, and mission-focused software development. Requires 3–5+ years with a BS or 1–2+ years with an MS in CS or related field, and U.S.

citizenship with active DoD SECRET clearance. You will contribute to mission-critical systems at STR’s Arlington, VA or Woburn, MA offices, with periodic travel and a

Qualifications

• BS or MS in Computer Science or a related technical field.
• 3–5+ years with BS, or 1–2+ years with MS, building maintainable APIs and software.
• U.S. Citizenship and active DoD SECRET Clearance required.

Responsibilities

• Build and scale: design and implement flexible microservices and high-performance APIs in a DevSecOps stack.
• Drive deployment: own features from R&D to active user community.
• Collaborate: work with scientists, engineers, and end users to translate requirements into production-grade software.
• Own your growth: trajectory driven by your interests and evolving R&D portfolio.

Skills

Scala

Functional programming

Type-driven design

Property-based testing

Self-directed

Ambiguity tolerance

Education

BS or MS in Computer Science or related field

Tools

CRDTs

Gossip protocols

OpenTelemetry

Python

Job description

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.

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, andenhancing 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.

Who You Are:

• 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 a 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.

Bonus Points:

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

Logistics

• Location: Hybrid at one of STR’s offices in Woburn, MA or Arlington, VA
• Travel: Periodic travel (up to 20%).

Pay Information

Full-Time Salary Range: $140,000.00 to $170,000.00

The salary range listed is based on external market data. Offers are based on factors, such as but not limited to, the candidate’s experience, education, training, key skills/critical skills, security clearances, and prevailing market and business conditions.

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.

STR is an equal opportunity employer. We are fully dedicated to hiring the most qualified candidate regardless of race, color, religion, sex (including gender identity, sexual orientation and pregnancy), marital status, national origin, age, veteran status, disability, genetic information or any other characteristic protected by federal, state or local laws.

If you need a reasonable accommodation for any portion of the employment process, email us at [e-mail] and provide your contact 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.

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For government reporting purposes, we ask candidates to respond to the below self‑identification survey. Completion of the form is entirely voluntary. Whatever your decision, it will not be considered in the hiring process or thereafter. Any information that you do provide will be recorded and maintained in a confidential file.

As set forth in STR’s Equal Employment Opportunity policy, we do not discriminate on the basis of any protected group status under any applicable law.

If you believe you belong to any of the categories of protected veterans listed below, please indicate by making the appropriate selection. As a government contractor subject to the Vietnam Era Veterans Readjustment Assistance Act (VEVRAA), we request this information in order to measure the effectiveness of the outreach and positive recruitment efforts we undertake pursuant to VEVRAA. Classification of protected categories is as follows:

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