Principal Software Engineer, Applications (Backend)

About Reach Security:

Reach Security (https://reach.security) builds self-driving cybersecurity. Reach employs the first generative AI for cybersecurity to oversee an organization's current security stack, aiming to achieve the best possible security posture with the products already in use.

About the Role:

We are seeking a Principal Backend Software Engineer to lead the design and development of our Applications layer, the backbone that powers our APIs, OLTP databases, and AI-driven capabilities. A core focus will be on security policy Drift Detection, ensuring organizations maintain alignment between intended policies and real-world configurations. You will also play a critical role in leveraging large language models (LLMs) to deliver intuitive interfaces for security teams.

The ideal candidate is a motivated problem solver who prioritizes high-quality solutions and excels in navigating ambiguity. As an early team member, you will have the opportunity to take ownership of various aspects of our backend from day one. Your role will be pivotal in establishing engineering best practices, balancing engineering priorities with business needs, and identifying innovative approaches to deliver outstanding value to our users. Your engineering knowledge will be applied by designing top-notch architectures, offering insightful feedback on technical designs, solving difficult problems and conducting thorough code reviews, all aimed at ensuring the software we build is both maintainable and dependable.

In this role, you will:

• Architect, design, and implement scalable APIs that expose security data and recommendations to customers and internal systems.

• Lead the design of OLTP database schemas that balance performance, normalization, and multi-tenant isolation at scale.

• Build core backend services that support Security Policy Drift Detection, modeling intended vs. actual configurations across diverse systems.

• Integrate LLMs into backend services to surface new insights in complex data.

• Drive technical direction for backend applications, balancing product requirements, performance, and long-term maintainability.

• Collaborate across engineering, product, and security teams to translate ambiguous goals into concrete architectures.

• Mentor engineers, elevate coding standards, and provide deep technical guidance through design and code reviews.

• Ensure system reliability and availability in production through sound observability practices and resilient architectures.

Success in this role requires:

• 8+ years of experience in backend software engineering, with significant time spent designing APIs and high-performance data systems.

• Production experience with Python and its ecosystem.

• Expertise in relational databases (schema design, indexing, query optimization, and OLTP performance tuning).

• Strong background in API design and development best practices.

• Experience with multi-tenant SaaS architectures, ensuring data isolation, scalability, and robust security.

• Deep understanding of data structures, algorithms, and computational complexity.

• Strong system design skills for building highly scalable and maintainable backend systems.

• Familiarity with integrating machine learning and AI models into production systems.

• Strong communication skills, with the ability to clearly convey complex technical concepts.

• US Citizenship or Green Card holder.

Ways to stand out:

• Experience with cybersecurity domains, especially configuration management, drift detection, or compliance automation.

• Expertise in database scaling, advanced query optimization, or OLTP/OLAP hybrid workloads.

• Hands-on experience with streaming or batch data pipelines.

• Knowledge of infrastructure-as-code (IaC) tools like Terraform, Pulumi, or AWS CDK.

• Background in logic programming (Prolog, Datalog) or control systems.

• Experience with mathematical optimization (scheduling, graph optimization).

Work arrangement:

• Competitive salary and equity.

• Comprehensive health, dental, and vision insurance.

• Remote work flexibility.