Telecom / ISP Security Engineer APPLIED AI RE VR ERICSSON HUAWEI NOKIA ZTE New York, NY / On Site →

Zealot Labs, Inc.; Greater London; Hybrid; GBP 100,000 - 195,000; Full time

Benefits offered by this job

Equity

Job summary

Zealot Labs, Inc. is hiring in London for an Early-stage security-focused engineer who builds AI systems to find and exploit vulnerabilities in telecom infrastructure.

The role emphasizes reverse engineering firmware, carrier-grade routing, and developing AI-driven tooling to map attack paths across SS7, GTP, and DIAMETER stacks. You'll work on on-site London premises, collaborating with a small, ownership-driven team backed by top-tier investors.

Qualifications

• Extensive experience reverse engineering telecom equipment and firmware.
• Strong C/C++ and Python for tooling and exploit development.
• Solid background in carrier-grade networks (core, access, or routing).
• Experience with vendor OS platforms (Nokia, Ericsson, Huawei, ZTE).

Responsibilities

• Build AI systems to identify vulnerabilities in carrier-grade telecom infrastructure.
• Reverse engineer firmware and management planes across vendors.
• Target subscriber-edge infrastructure like BRAS/BNG/AAA/RADIUS stacks.
• Develop AI tooling to discover attack paths through SS7, GTP, DIAMETER.
• Translate telecom domain knowledge into scalable backbone-level data systems.
• Work with telco security teams to harden core networks.
• Contribute to building scalable AI agents and tooling.
• Move from manual research toward automated AI-driven security solutions.

Skills

C/C++

Python

Telecom security

Tools

Cisco IOS-XR

Juniper Junos

Nokia SR OS

Huawei VRP

Job description

Zealot is deploying AI systems at the center of western cyber operations , backed by tier-1 US VCs and industry leaders. Our team includes alumni of Anthropic, xAI, and Anduril. Soon live with close U.S. allies abroad.

APPLIED AI RE VR ERICSSON HUAWEI NOKIA ZTE

Compensation 100K-195K + skin in the game equity

Location London, United Kingdom On Site

Stage Early-stage startup backed by tier 1 investors. Small, growing team with exceptionally high ownership.

• + Build AI systems that find and exploit vulnerabilities in carrier-grade telecom and ISP infrastructure: core routers, BRAS/BNG, GPON/EPON, DSLAM, CMTS, and mobile packet core.


• + Reverse engineer firmware and management planes on equipment from Nokia, Ericsson, Huawei, ZTE, Calix, and similar vendors to train models that generalize across platforms.


• + Target subscriber-edge infrastructure (BRAS, BNG, AAA systems, and RADIUS/DIAMETER stacks) where authentication, session control, and policy enforcement converge.


• + Develop AI-driven tooling that discovers attack paths through SS7, GTP, DIAMETER, and carrier routing infrastructure at scale.


• + Turn deep telecom domain knowledge into the systems and data that let machines operate at the backbone level.


• + Strong experience with telecom or ISP infrastructure security: core networks, access networks, or carrier routing.


• + Familiarity with carrier-grade platforms: Cisco IOS-XR, Juniper Junos, Nokia SR OS, Huawei VRP, or similar.


• + Understanding of telecom protocols: SS7/SIGTRAN, GTP, DIAMETER, RADIUS, MPLS, BGP at carrier scale, GPON/EPON.


• + Experience reverse engineering network equipment firmware or proprietary network operating systems.


• + Strong C/C++ or Python skills for tooling and exploit development.

Nice to Have

• + Experience with mobile core network elements (MME, SGW, PGW, HSS, or 5G equivalents).


• + Familiarity with BRAS/BNG, DSLAM, CMTS, OLT, or other access and subscriber-edge network equipment.


• + Published CVEs or advisories against telecom or ISP equipment vendors.


• + Experience with TR-069/CWMP, NETCONF/YANG, RADIUS/DIAMETER AAA, or carrier management protocols.


• + Experience building with LLMs and AI agents.


• + Background in CNO, SIGINT, or government telecom operations.


• + Clearly interested in stepping away from purely manual research and moving toward the development of AI systems.


• + Building something massive matters more to you than comfort, titles, or predictability.


• + You want to be early at a company that will change an industry, and you're ready to do what that actually takes.

Note to recruiting firms: Telecom or ISP infrastructure security experience is the core requirement. Carrier-grade routing, mobile core, or access network experience is essential. Candidates from telco vendor security teams, CNO backgrounds, or ISP engineering are ideal.

Ready?