{"id":752731,"url":"https://alion.io/job/sonicwall-senior-software-engineer-embedded-c-firewall-client","title":"Senior Software Engineer — Embedded C / Firewall Client","company":{"id":685324,"name":"SonicWall","domain":"sonicwall.com","url":"https://alion.io/company/sonicwall","size_band":"501-1000","is_staffing_agency":false,"employer_type":"direct","is_intermediary":false,"listed_via":null,"ats_vendor":"Greenhouse","truth_index":{"grade":"B","score":75,"open_postings":4,"ghost_share":0,"stale_share":1,"repost_share":0,"time_to_fill_p50_days":38,"computed_at":"2026-10-07T05:47:15Z"}},"role":"Hardware","role_family":"Hardware","seniority":"senior","employment_type":null,"work_mode":"on_site","remote_scope":null,"remote_scope_basis":null,"remote_working_hours":null,"hiring_geo_confidence":"structured","locations":["Bengaluru, India"],"countries":["IN"],"hiring_countries":[],"hiring_countries_total":0,"salary":null,"salary_estimate":{"min_usd":18000,"max_usd":46000,"period":"year","method":"role_seniority_country_remote_cell","sample_n":14},"experience_years_min":8,"visa_sponsorship":false,"relocation_package":false,"has_equity":false,"technologies":[{"name":"C++","optional":false},{"name":"Tcpdump","optional":false},{"name":"Wireshark","optional":false}],"status":"live","first_seen_at":"2026-07-09T21:03:17Z","employer_posted_date":"2026-09-17","last_verified_at":"2026-10-07T22:32:49Z","board_verified":true,"closed_at":null,"days_open":90,"trust":{"level":"ok","repost_count":null,"flags":[],"days_open":90},"description":"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.\nAbout the Role\nSonicWall is hiring a Senior Software Engineer to develop and maintain the Content Filtering Service client embedded in SonicOS - the firmware running on SonicWall firewall appliances worldwide. This module intercepts live traffic, queries the CFS rating servers in real time, and enforces URL-based content filtering policies at the packet level. This is security-critical code: a policy bug is a traffic bypass on a deployed security appliance.\nThe codebase is in C with a split Control Plane / Data Plane architecture, multi-blade cache synchronization, and multiple firmware version upgrade paths.\nResponsibilities\nMaintain, harden, and extend the CFS client module across both the control plane and data plane.\nOwn the binary UDP protocol implementation between the firewall and the CFS rating servers, ensuring correctness and compatibility across protocol versions.\nDevelop and maintain complete IPv4 and IPv6 support across all code paths.\nOwn the firmware upgrade and migration paths, ensuring they are atomic, failure-safe, and correctly handle all supported version transitions.\nImprove reliability of inter-blade cache synchronization on multi-blade appliances.\nCollaborate with the server-side on coordinated protocol changes.\nDocument the concurrency model, upgrade invariants, and dataplane integration for long-term maintainability.\nCollaborate asynchronously with a US-based team and the India-based server team.\nRequirements\nExpert-level C (not C++): disciplined manual memory management, pointer arithmetic, and systems design.\nMulti-core concurrency in C: reader-writer locks, spinlocks, atomic operations, and memory ordering.\nKernel-level networking: deep understanding of how a packet moves through a firewall dataplane - TCP/UDP processing, flow cache, connection tracking. Userspace socket programming alone is not sufficient.\nStrong IPv4 and IPv6 across all code paths.\nComfortable navigating and owning a large C codebase with multiple subsystems.\nExperience with network testing and debugging tools: packet capture (Wireshark/tcpdump), traffic generators, GDB.\nGood written English for remote, asynchronous collaboration.\nNice to have:\nExperience with multi-blade or multi-ASIC hardware platforms (Octeon/CVMX or similar).\nUnderstanding of symmetric encryption (AES-CBC, DES) at the C implementation level.\nPrior experience on a security appliance, network device, or UTM firmware codebase.\nFamiliarity with TLV binary protocol design and versioning.\nExperience with C fuzz testing or sanitizers (AFL, AddressSanitizer, ThreadSanitizer).\nEducation & Experience\nAt least 8 years of related experience with a Bachelor's degree; or 6 years with a Master's degree; or a PhD with 3 years' experience; or equivalent experience preferred. Degree in Computer Science, Engineering, or related field preferred.\nSonicWall is an equal opportunity employer. \nWe are committed to creating a diverse environment and are an equal opportunity employer. All qualified applicants receive consideration for employment without regard to race, color, ethnicity, religion, sex, gender, gender identity and expression, sexual orientation, national origin, disability, age, marital status, veteran status, pregnancy, or any other basis prohibited by applicable law.\nAt SonicWall, we pride ourselves on recruiting a diverse mix of talented people and providing active security solutions in 100+ countries.\nApplicant Privacy Notice","description_format":"text","description_chars":4263,"description_truncated":false,"requirements":{"experience_years_min":8,"management_years_min":null,"team_size_min":null,"manages_managers":false,"education":{"level":"bachelor","optional":false},"security_clearance":false,"languages":[{"language":"English","level":"All levels","optional":false}]},"benefits":[],"hiring_locations":[],"hiring_excludes":[],"relocation_offered":false,"industries":[],"lifecycle":[{"event":"open","at":"2026-09-11T16:11:28Z"}],"visa":[],"liveness":{"score":24,"band":"cold","label":"Long shot","p_open":1,"p_active":0.672,"p_room":0.35,"age_days":89,"expected_fill_days":38,"reasons":["conf:2","velocity","win:tail"],"computed_at":"2026-10-07T05:47:15Z"},"pay":null,"html_url":"https://alion.io/job/sonicwall-senior-software-engineer-embedded-c-firewall-client","json_url":"https://alion.io/job/sonicwall-senior-software-engineer-embedded-c-firewall-client.json","meta":{"generated_at":"2026-10-08T00:25:06Z","cache_seconds":300,"methodology":"https://alion.io/methodology","terms":"https://alion.io/terms","contact":"https://alion.io/contact","api":"https://alion.io/developers","about":"Alion is a live layer of people, companies and AI agents: who they are, whether they are real and active right now, what they do and how to work with them, readable by people and by agents and paid per call.","catalog":"https://alion.io/catalog.json","usage":{"tier":"crawler","counted_by":"address","units_charged":1,"used_today":539,"day_limit":5000,"remaining_today":4461,"minute_limit":60,"resets_at":"2026-10-09T00:00:00Z"}},"offers":[{"id":"company.slices","title":"One company in depth, by slice","status":"live","price":{"credits":0.02,"usd":0.002,"plus_per_slice":{"credits":0.05,"usd":0.005}},"unit":"per company, plus each slice with data","note":"the employer in depth","call":{"mcp_tool":"get_company","arguments":{"id":685324},"rest":"https://alion.io/mcp/rest/get_company?id=685324"},"human":"https://alion.io/catalog?offer=company.slices&for=job%2Fsonicwall-senior-software-engineer-embedded-c-firewall-client"},{"id":"market.stats","title":"A market slice: pay, demand and time to fill","status":"live","price":{"credits":1,"usd":0.1},"unit":"per slice","note":"pay, demand and time to fill for this role and place","call":{"mcp_tool":"market_stats"},"human":"https://alion.io/catalog?offer=market.stats&for=job%2Fsonicwall-senior-software-engineer-embedded-c-firewall-client"},{"id":"job.search","title":"Open jobs by role, technology, place, pay and visa","status":"live","price":{"credits":0.02,"usd":0.002},"unit":"per posting in a list","note":"similar open postings","call":{"mcp_tool":"search_jobs"},"human":"https://alion.io/catalog?offer=job.search&for=job%2Fsonicwall-senior-software-engineer-embedded-c-firewall-client"},{"id":"company.verify","title":"Is this company real and active right now","status":"pilot","price":null,"unit":"per company","request":{"url":"https://alion.io/catalog/request","method":"POST","body":"{\"offer\": \"company.verify\", \"for\": \"job/sonicwall-senior-software-engineer-embedded-c-firewall-client\", \"note\": \"what you need it for\"}"},"human":"https://alion.io/catalog?offer=company.verify&for=job%2Fsonicwall-senior-software-engineer-embedded-c-firewall-client"}]}