Principal Software Engineer — Content Filtering Platform
Skills
About the role
SonicWall is a cybersecurity forerunner with more than 30 years of expertise and is recognized as a leading partner-first company, ensuring our partners and their customers are never alone in the fight against cybercrime. With the ability to build, scale and manage security across the cloud, hybrid and traditional environments in real-time, SonicWall provides relentless security against the most evasive cyberattacks across endless exposure points for increasingly remote, mobile and cloud-enabled users. With its own threat research center, SonicWall can quickly and economically provide purpose-built security solutions to enable any organization - enterprise, government agencies and SMBs - around the world. For more information, visit www.sonicwall.com or follow us on Twitter, LinkedIn, Facebook and Instagram.
About the Role
SonicWall is looking for a Principal Software Engineer to own the technical direction and hands-on development of our Content Filtering Service (CFS) server platform - a high-throughput, multi-threaded C++17 system that SonicWall firewalls worldwide rely on in real time to categorize URLs and enforce content filtering policies.
This is a heavily hands-on role. You will write and own production code daily, set technical direction, drive the roadmap, and mentor senior engineers - all while remaining deeply involved in the code itself. You will also be the primary bridge between the India-based engineering team and US-based management, requiring strong communication and the ability to work effectively across time zones.
Responsibilities
Write, review, and own production C++ code across the server platform: the URL rating server, the cloud categorization relay server, and the shared common libraries.
Drive security hardening of the binary UDP protocol, including encryption key management and protocol integrity.
Continuously improve code quality: modernize memory ownership patterns, improve concurrency safety, and reduce technical debt.
Set coding standards, conduct code reviews, and provide technical mentorship to the Senior Engineers on the team.
Build and maintain comprehensive architecture documentation and design knowledge across the platform.
Establish and drive an automated testing strategy, including C++ unit testing frameworks and integration test standards.
Identify and prioritize technical debt and drive a realistic roadmap to address it.
Oversee GitLab CI/CD pipelines, DEB/RPM packaging, and production deployment processes.
Maintain platform-wide awareness to contribute to architecture decisions spanning the server, firewall client, and web platform.
Work closely with US-based engineering and management to communicate project status, priorities, and risks clearly and proactively.
Requirements
Expert-level C++17: move semantics, smart pointers, concurrency primitives (std::shared_mutex, std::atomic), RAII, and performance-sensitive systems code.
Strong Linux systems programming: POSIX threads, epoll-based I/O multiplexing, and high-throughput UDP socket programming.
Experience with high-throughput server design: thread pool patterns, cache architecture, lock-free data paths, and performance benchmarking.
Applied cryptography: symmetric encryption (AES-CBC), key management, and integrity checks.
Familiarity with CMake-based build systems, Linux packaging (DEB/RPM), and GitLab CI/CD pipelines.
Comfortable taking ownership of a complex, production codebase and driving it forward independently.
Excellent written English for asynchronous collaboration with a US-based team.
Nice to have:
Experience with binary protocol design (TLV framing, protocol versioning, wire compatibility).
Knowledge of DNS protocol internals.
Experience with RabbitMQ or AMQP from a C++ client perspective.
Background in network security, UTM appliances, or content filtering products.
Experience integrating closed-source third-party SDKs into a CMake build.
Education & Experience
At least 10 years of related experience with a Bachelor's degree; or 8 years with a Master's degree; or a PhD with 6 years' experience; or equivalent experience preferred. Degree in Computer Science, Engineering, or related field preferred.
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At SonicWall, we pride ourselves on recruiting a diverse mix of talented people and providing active security solutions in 100+ countries.
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