Application Security Engineer (AppSec)

Recruitment Room; United States; Remote; USD 58,000 - 192,000; Part time

Job summary

Appsierra Group is seeking an Applications Security Engineer (AppSec) with strong backend experience to help evaluate and harden AI-enabled systems. You will design realistic coding tasks, build deterministic verifiers, and work across Java, Node.js, Go, Rust, TypeScript, Python, and C++.

The role blends secure coding, vulnerability assessment, and code reviews, with emphasis on OWASP/CWE practices and threat-focused analysis.

Qualifications

• Strong backend development experience across Java, Node.js, Go, Rust, TypeScript, Python or C++.
• Experience building scalable services and APIs.
• Strong debugging, performance optimization, and automated testing skills.
• Solid code review and software engineering judgment.
• Practical application security or cybersecurity experience.
• Experience with secure coding, AppSec, penetration testing or vulnerability assessment.
• Ability to identify and resolve bugs, vulnerabilities and bottlenecks.
• Experience refactoring complex codebases and implementing features.
• Strong CS fundamentals: algorithms and data structures.

Responsibilities

• Design realistic coding tasks involving feature implementation, bug fixing, refactoring, and application security.
• Build deterministic verifiers that accept valid solutions and reject incorrect ones.
• Work with backend codebases and scalable services across languages listed in the ad.
• Debug complex software issues and identify performance bottlenecks.
• Review code for correctness, maintainability, performance, and security.
• Identify application vulnerabilities and assess risks.
• Apply secure coding principles and modern AppSec practices.
• Use OWASP, CWE concepts and security-focused code reviews where applicable.
• Document technical reasoning, expected behavior, vulnerabilities, and evaluation criteria.
• Create high-quality technical inputs to improve AI coding and software systems.

Skills

Backend development

Java

Node.js

Go

Rust

TypeScript

Python

C++

APIs

Debugging

Security testing

Penetration testing

Vulnerability assessment

OWASP CWE

Code review

Tools

CI/CD

Static analysis

Threat modeling

Job description

Application Security Engineer (AppSec)

Contract · Remote · Approximately 15 hours/week

Annual Compensation Equivalent: $57,600–$192,000/year
Hourly Rate: $30–$100/hr

The annual compensation equivalent is calculated at 40 hours/week across 48 workable weeks/year and represents a full-time equivalent, not guaranteed earnings. Actual compensation is output-based and depends on completed tasks and project requirements.

About the Role

We’re looking for Application Security Engineers (AppSec) with strong backend engineering experience and practical cybersecurity knowledge to help evaluate and improve next-generation AI systems.

You’ll create realistic, challenging software engineering tasks involving feature implementation, bug fixing, security issues, and complex codebases. You’ll also build deterministic verifiers that can reliably distinguish valid solutions from incorrect implementations.

The role combines backend software engineering with application security, secure coding, vulnerability assessment, and code review. No prior AI experience is required.

What You’ll Do

• Design realistic coding tasks involving feature implementation, bug fixing, refactoring, and application security.

• Build deterministic verifiers that accept reasonable valid solutions and reject incorrect implementations.

• Work with backend codebases and scalable services across languages such as Java, Node.js, Go, Rust, TypeScript, Python, and C++.

• Debug complex software issues and identify performance bottlenecks.

• Review code for correctness, maintainability, performance, and security.

• Identify application vulnerabilities and assess potential security risks.

• Apply secure coding principles and modern application security practices.

• Use concepts from penetration testing, vulnerability assessment, OWASP, CWE, and security-focused code reviews where applicable.

• Document technical reasoning, expected behavior, vulnerabilities, and evaluation criteria.

• Create high-quality technical inputs that help improve AI coding and software engineering systems.

What We’re Looking For

• Strong backend development experience with Java, Node.js, Go, Rust, TypeScript, Python, C++, or a similar language.

• Experience building scalable services and APIs.

• Strong debugging, performance optimization, and automated testing skills.

• Solid code review and software engineering judgment.

• Practical application security or cybersecurity experience.

• Experience with secure coding, AppSec, penetration testing, vulnerability assessment, or security-focused code reviews.

• Ability to identify and resolve software bugs, vulnerabilities, and system bottlenecks.

• Experience refactoring complex codebases and implementing substantial features.

• Strong understanding of algorithms, data structures, and core computer science concepts.

• Strong analytical, problem-solving, and technical communication skills.

Cybersecurity & AppSec Experience

Relevant experience may include:

• Application security engineering

• Secure software development

• Security code reviews

• Penetration testing

• Vulnerability assessment

• OWASP and CWE

• Threat-focused code analysis

• Security testing and remediation

• Secure API and backend development

• Security audits and risk identification

• SecOps or related security engineering work

Assessment & Selection Process

The process may include:

1. Application and screening questions

2. Approximately 30-minute AI interview

3. Technical assessment, if required

4. Hiring manager review

The interview and assessment stages are designed to evaluate your own technical reasoning and problem-solving ability, so candidates are expected to complete them without outside assistance. The same principle applies to project work.

Schedule & Engagement

• Remote contractor engagement

• Approximately 15 hours per week

• Flexible schedule — choose your hours and days, including weekends if preferred

• Compensation is output-based and tied to tasks that meet project specifications

• Minimum weekly task submission requirements apply

• Task completion time may vary depending on complexity, experience, and workflow

Start Timeline

Selected candidates should be ready to begin promptly. After completing onboarding, you should be prepared to start your first tasks within approximately 24–48 hours.