Staff Software Engineer - Security Engineering

Twilio is shaping the future of communications, delivering developer-first solutions to hundreds of thousands of businesses and empowering millions of developers globally.

As a Staff Software Engineer, you will shape the next generation of fraud prevention products by bringing Stytch capabilities to Twilio’s customer base. You will primarily work on Twilio's Device Fingerprinting product, which detects bots, manual abuse, and sophisticated reverse engineering to keep customer platforms secure. Operating with a startup mindset backed by Twilio's scale, you will analyze browser and device internals, build complex signal collection mechanisms, and partner with cross-functional leaders to evolve threat detection strategies.

Key Responsibilities

• Device Fingerprinting & Signal Collection: Build and own core fraud detection capabilities, diving deep into browser and device internals to collect signals that identify bad actors, bots, and automated abuse.
• Architectural Leadership & Ownership: Author detailed design documents, drive key technical decisions, conduct code reviews, and maintain direct technical ownership over production systems.
• Roadmap & Product Alignment: Partner closely with Product and Engineering leadership to translate customer requirements into concrete technical roadmaps and high-impact security features.
• Cross-Team Integration: Collaborate across Twilio and Stytch engineering teams to align architectural standards, integrate identity capabilities, and unblock platform initiatives.
• Production Resilience & Observability: Drive production quality, incident response, and system resilience through observability frameworks, logging, and automated telemetry.
• Mentorship & Team Elevation: Pair with, mentor, and guide engineers across the organization to elevate coding standards and foster a high-ownership engineering culture.

Requirements

Academic & Experience Background

• 6+ years of professional experience designing, building, and operating production software systems.
• Bachelor’s degree in Computer Science or equivalent practical industry experience.

Technical Competencies & Skills

• Expertise in C or C++ (production experience is a plus).
• Hands-on experience working within a production-grade codebase using modern programming languages and software engineering best practices.
• Excellent written and verbal communication skills with a track record of authoring clear technical design documents.
• Ability to participate in a non-standard on-call rotation including weekend and holiday coverage.

Desired Qualifications

• Familiarity with JavaScript, Go, or WebAssembly.
• Practical experience with reverse engineering or reverse engineering detection and defense mechanisms (e.g., browser automation defense, botting mitigation, anti-analysis tooling).
• Offensive or defensive security software engineering background.
• "Builder" mindset with a passion for hands-on technical execution and rapid iteration.