Senior Application Security Engineer

CharterUP; Austin (TX); Hybrid; USD 130,000 - 190,000; Full time

Benefits offered by this job

Remote-first

Health insurance

Paid time off

401(k) plan

Disability insurance

Job summary

CharterUP is seeking a Senior Application Security Engineer to raise the bar on secure software. You will own tooling, drive vulnerability remediation, and lead threat modeling and design reviews for high-risk systems.

You'll focus on authentication, authorization, payments, and customer data, while strengthening AWS security and building reusable security libraries and guardrails. This role is based in Austin, with hybrid in-office days.

Qualifications

• 5+ years in software engineering or security
• 3+ years in application security
• Experience with Java/TypeScript and security tooling
• Familiarity with SOC 2, PCI DSS, and GDPR
• Experience with AWS security

Responsibilities

• Own security tooling and vulnerability management end-to-end.
• Lead security design reviews and threat modeling.
• Perform targeted manual code reviews for high-risk systems.
• Strengthen AWS security and logging practices.
• Scale security through secure defaults and developer guardrails.

Skills

Java

TypeScript

Threat modeling

AWS security

Secure coding

Code review

Tools

SAST

Container scanning

Secret detection

Penetration testing

Job description

About CharterUP. CharterUP is transforming the $450+ billion group transportation and mobility market with an AI native platform that powers modern charter, shuttle, and emerging autonomous vehicle operations. Trusted by many Fortune 500 companies, CharterUP connects enterprises, institutions, and event organizers to thousands of bus operators nationwide, while increasingly serving as the operating system for large scale shuttle and transit programs across airports, campuses, industrial sites, and major events.

Through real time availability, transparent pricing, intelligent routing, and AI driven dispatch and optimization, CharterUP replaces a fragmented and opaque industry with automation, accountability, and scale.

Why Join Us

• Innovative Impact: Be part of the team that's revolutionizing group travel, setting new standards in an industry overdue for change.
• Growth Opportunities: As a hyper growth company and one of the fastest-growing companies recognized by Inc., there’s no better time to join our dynamic, growth-stage organization.
• Driven Team: Collaborate with some of the most driven minds in tech, all while working in a remote-first environment with a tech hub in Austin, TX.
• Funding and Stability: Our $60 million Series A funding was just the start—we’re poised for even greater expansion, and you can be part of this exciting journey. CharterUp has achieved this growth profitability and efficiently, ensuring long-term stability.

About the Role

CharterUP is seeking a Senior Application Security Engineer to raise the bar on how we build and ship secure software. This is a dedicated security role on the Platform Engineering team. Our applications handle customer PII, passenger manifests, trip and location data, and payment flows, and they enforce authorization boundaries between thousands of parties in a two-sided marketplace. You'll be the technical leader on application security here, setting our standards, defining what "secure enough to ship" means, owning security decisions in design and code review, and driving vulnerabilities through remediation. Expect to split your time roughly evenly between building security tooling and automation and conducting threat modeling, design reviews, and targeted code reviews.

Title: Senior Application Security Engineer

Reports to: Engineering Manager

Location: Austin, TX (Hybrid: Monday, Wednesday, Friday in-office)

What You’ll Do

• Own security tooling and vulnerability management across SAST, dependency and container scanning, secret detection, and penetration testing, including triage, routing, and remediation SLAs
• Lead security design reviews, threat modeling, and targeted manual code reviews for high-risk systems, including authentication, authorization, payments, and customer data
• Identify and prevent multi-tenant authorization vulnerabilities across quoting, booking, and trip workflows through scalable patterns and automated testing
• Strengthen AWS security through IAM and account boundary design, secrets management, workload protection, and comprehensive logging
• Scale security across engineering by building secure defaults, reusable libraries, automation, and developer guardrails, and establishing a security champions practice

What You’ll Bring

• 5+ years of experience in software engineering or security, including 3+ years in application or product security
• Strong software engineering skills in Java and/or TypeScript, with experience building production-grade security tooling, automation, libraries, and developer-facing solutions
• Deep expertise in application security, including threat modeling, secure system design, authentication, authorization, access control, injection, SSRF, and manual code review; familiarity with security and compliance standards, including SOC 2, PCI DSS, and GDPR is a plus.
• Hands-on experience with AWS and cloud-native security, including IAM, multi-account architecture, containerized workloads, CI/CD security, and vulnerability management
• Strong technical judgment and influence, with the ability to set security standards, prioritize risk, and drive remediation across engineering teams without direct authority
• Step 1 - Video call: Talent Acquisition interview
• Step 2 - Video call: Technical interview
• Step 3 - Video call: Team interviews
• Step 4 - Offer & reference check
• Welcome aboard!

Global Benefits & Perks at CharterUP

We believe great people can live anywhere—and they deserve great benefits, too. While offerings may vary slightly by location, we prioritize hiring near our hubs in Austin, Atlanta, Miami, and Denver as we grow our global team.

• Flexible Work Model: CharterUP operates as a remote-first company, with select roles requiring regular, in-office presence based on team and business needs. Role-specific expectations will be shared during the hiring process. U.S.-based employees may reside in any of our 19 approved states.
• Comprehensive Health & Wellness: Medical, dental, and vision insurance, mental health support, virtual care, gym discounts, and family-building benefits. In the U.S., we cover 100% of premiums for employees. International benefits align with local standards.
• Time Off to Recharge: Paid time off so you can truly unplug. U.S.: 15 PTO days (increasing to 20 after 2 years) + 8 paid holidays. International policies vary by country.
• Financial Peace of Mind: Company-paid life, short-term, and long-term disability insurance where available.
• Performance-Driven Culture: Join a fast-moving, ambitious, and collaborative team that wins together.
• Referral Rewards: Earn bonuses for bringing top talent to the team.
• Planning for the Future: Long-term financial planning support. U.S.: 401(k) plan. International: region-specific savings programs where applicable.
• Top-Tier Tech: Choose a Mac or PC, plus monitor, keyboard, and mouse to hit the ground running.

CharterUP is an Equal Opportunity Employer. We are committed to creating an inclusive, accessible, and respectful workplace. We consider all qualified applicants without regard to race, color, religion, sex, sexual orientation, gender identity or expression, age, national origin, ancestry, disability, medical condition, marital status, veteran status, or any other protected characteristic in accordance with applicable federal, state, and local laws in the United States and Canada. If you require accommodation during the recruitment process, please let us know. CharterUP is committed to providing reasonable accommodations during the hiring process. If you need assistance or an accommodation, please contact your recruiter.

Hiring Locations: CharterUP U.S.-based candidates and employees must reside in one of the following states: Arizona, Colorado, Florida, Georgia, Hawaii, Mississippi, Missouri, North Carolina, New Hampshire, Nevada, New York, Oklahoma, South Dakota, Tennessee, Texas, Utah, Washington, and Wyoming.

We hire in the U.S. and Canada and are actively expanding our global footprint.