Security Engineer II, Application Security

Summary

Trail of Bits is a cybersecurity company focused on research-based security assessments and custom engineering for emerging technology risks. The Security Engineer II will independently conduct application security assessments, discover and validate vulnerabilities, develop custom tooling, perform threat modeling and architecture reviews, and communicate findings to clients.

Responsibilities

• Security Assessment Ownership: Independently lead assessments of substantial components, modules, or systems within client engagements and own the work from scoping through delivery
• Vulnerability Discovery and Analysis: Find and validate vulnerabilities, establish root causes and exploitation paths, assess impact, and develop proof-of-concept code when appropriate
• Custom Security Tooling: Design and build targeted tools, harnesses, tests, or automation that expand assessment coverage and improve repeatability
• Architecture and Threat Modeling: Review complex software architectures, identify attack surfaces, data flows, trust and privilege boundaries, and recommend practical mitigations
• Client Communication: Produce clear, actionable findings, defend the evidence behind them, and lead technical discussions with client engineering teams
• Team Contribution: Review other engineers' code and analysis, share techniques, and help improve the team's technical approach
• Research and Innovation: Contribute new methods, open-source tools, and technical writing to Trail of Bits and the broader security community

Skills

• Typically 2+ years of directly relevant experience in application security, vulnerability research, security-focused software engineering, or a closely related area. Relevant experience may include professional work, research, open-source contributions, or substantial academic or independent projects; demonstrated depth and independence matter more than a strict year count
• Repeated vulnerability-discovery experience. You can talk through vulnerabilities you personally found or validated, including how you identified them, established exploitation paths and impact, and distinguished them from false positives or low-impact defects
• Strong code-analysis skills across unfamiliar and complex codebases, including tracing execution and data flow, identifying logic and implementation flaws, and reviewing the security implications of system design
• Strong programming and debugging ability in at least two relevant languages, such as Rust, Go, C, C++, Python, JavaScript, TypeScript, or similar languages used in security analysis and tool development
• Working knowledge of memory-corruption vulnerabilities and mitigations, including the ability to reason about exploit primitives, defensive mechanisms, and the practical security impact of implementation choices
• Strong systems knowledge, including operating systems, IPC, privilege boundaries, system internals, and how applications interact with the platform around them
• Demonstrated ability to independently scope and execute a code-level security-assessment workstream, prioritize attack surfaces, build or adapt tooling, document evidence, and deliver findings
• Clear written and verbal communication, including experience presenting technical conclusions to software engineers or clients and contributing effectively on a distributed team
• Active or recent CTF participation, competition results, or comparable hands-on security challenges
• Published vulnerability research, CVEs, responsible disclosures, bug bounty findings, conference presentations, or technical writeups
• Contributions to open-source security tools, libraries, or research
• Experience with mobile application security, mobile system internals, or binary analysis on mobile platforms
• Experience assessing cloud platforms or infrastructure and working with tools such as Kubernetes, Helm, Terraform, or Ansible
• Experience with kernel code, drivers, reverse engineering, fuzzing, symbolic execution, or other low-level systems work
• Experience building security tools used by other engineers or across multiple assessments
• Experience leading client-facing technical discussions or mentoring other security engineers

Qualifications

Must Haves

• Typically 2+ years of directly relevant experience in application security, vulnerability research, security-focused software engineering, or a closely related area. Relevant experience may include professional work, research, open-source contributions, or substantial academic or independent projects; demonstrated depth and independence matter more than a strict year count
• Repeated vulnerability-discovery experience. You can talk through vulnerabilities you personally found or validated, including how you identified them, established exploitation paths and impact, and distinguished them from false positives or low-impact defects
• Strong code-analysis skills across unfamiliar and complex codebases, including tracing execution and data flow, identifying logic and implementation flaws, and reviewing the security implications of system design
• Strong programming and debugging ability in at least two relevant languages, such as Rust, Go, C, C++, Python, JavaScript, TypeScript, or similar languages used in security analysis and tool development
• Working knowledge of memory-corruption vulnerabilities and mitigations, including the ability to reason about exploit primitives, defensive mechanisms, and the practical security impact of implementation choices
• Strong systems knowledge, including operating systems, IPC, privilege boundaries, system internals, and how applications interact with the platform around them
• Demonstrated ability to independently scope and execute a code-level security-assessment workstream, prioritize attack surfaces, build or adapt tooling, document evidence, and deliver findings
• Clear written and verbal communication, including experience presenting technical conclusions to software engineers or clients and contributing effectively on a distributed team

Nice to Haves

• Active or recent CTF participation, competition results, or comparable hands-on security challenges
• Published vulnerability research, CVEs, responsible disclosures, bug bounty findings, conference presentations, or technical writeups
• Contributions to open-source security tools, libraries, or research
• Experience with mobile application security, mobile system internals, or binary analysis on mobile platforms
• Experience assessing cloud platforms or infrastructure and working with tools such as Kubernetes, Helm, Terraform, or Ansible
• Experience with kernel code, drivers, reverse engineering, fuzzing, symbolic execution, or other low-level systems work
• Experience building security tools used by other engineers or across multiple assessments
• Experience leading client-facing technical discussions or mentoring other security engineers

Benefits

• Performance-based bonuses.
• Fully company-paid insurance packages, including health, dental, vision, disability, and life.
• A solid 401(k) plan with a 5% match of your base salary.
• 20 days of paid vacation with flexibility for more, adhering to jurisdictional regulations.
• 4 months of parental leave to cherish the arrival of new family members.
• If you are interested in moving to NYC, $10,000 in relocation assistance to support your transition.
• $1,000 Working-from-Home stipend to create a comfortable and productive home office.
• Annual $750 Learning & Development stipend for continuous personal and professional growth.
• Company-sponsored all-team celebrations, including travel and accommodation, to foster community and recognize achievements.
• Philanthropic contribution matching up to $2,000 annually.