About the Role

The Lead Software Engineer is a critical role responsible for providing technical leadership within a domain-aligned cohort, guiding engineers in delivering quality, scalable SaaS products. You will leverage AI tools and co-worker agents such as Claude Code to specify, implement, validate, deploy, and support the most complex features end-to-end, focusing your expertise on architectural judgment, specification quality, and mentorship.

This position partners closely with the Engineering Manager on cohort health and delivery, interfaces with Product Managers and stakeholders to translate business requirements into technical specifications, and plays a key role in building the cohort's collective expertise. You'll drive AI-assisted development practices

and standards, mentor engineers across the cohort, and advise on tools and technologies that evolve our development organization.

What You'll Do

Technical Leadership & Specification
• Provide technical leadership within the cohort, guiding engineers in spec-driven, AI-assisted development
• Own specification quality for the most complex features, ensuring specs are comprehensive, unambiguous, and address all edge cases and non-functional requirements
• Collaborate with the Product Manager and stakeholders to translate business requirements into detailed technical specifications, and explain technical concepts to both technical and non-technical audiences
• Other duties as assigned.

AI-Assisted Implementation & Quality
• Lead AI-assisted implementation for complex features, using AI coding tools such as Claude Code to generate implementations from specifications
• Review AI-generated code and peer contributions for correctness, security, performance, and architectural alignment
• Validate AI-generated tests and ensure comprehensive test coverage for complex scenarios
• Drive AI workflow standards and best practices across your cohort, advise on tools and technologies to evolve our development organization, and share learnings with other cohorts

Software Design, Delivery & Mentorship
• Create software designs that consider both current and future requirements with a DevOps mindset that will scale as our volumes increase
• Design and implement REST APIs following established patterns, and support and maintain both UI and backend services within your cohort's domain
• Lead technical decisions and own domain expertise within your cohort
• Mentor engineers across the cohort on effective AI tool usage, spec writing techniques, and code review practices

What You'll Bring

Required Skills:
• 7+ years of relevant software engineering experience, with at least 2 years designing and implementing enterprise SaaS systems
• Bachelor's degree in Computer Science (or equivalent experience), along with a firm understanding of data structures and scalable software design
• Experience coding enterprise systems at scale, with mastery of C#, C++, PHP, Java, Node.js or a similar high-level language
• Proficiency in HTML5, CSS/Sass, Angular, React, TypeScript/JavaScript, and other web technologies, with a strong ability to design and implement REST APIs
• Strong understanding of SQL and relational databases (such as SQL Server or MySQL), and proficiency in multiple persistence technologies such as NoSQL and indexed files
• Demonstrated experience working with AI coding assistants (Claude Code, Codex, Cursor, or similar), including strong code review skills to validate correctness and identify issues in AI-generated and human-written code
• Strong collaboration and communication skills, with a track record of mentoring engineers and translating business requirements into technical specifications alongside Engineering Managers, Product Managers, and cross-functional teams
• Well-honed skills in source control management using Git or similar, and experience with AWS, Azure, or a similar cloud platform

Preferred Skills:
• Experience with spec-driven, agentic AI workflows where engineers delegate autonomous tasks to AI tools and provide guidance and oversight
• Experience establishing AI development practices or standards across teams
• Understanding of testable application design principles
• Track record of advising on tools and technologies that improved team productivity

The expected base salary range for this position is $157,000 - $208,000 annually.

Compensation may vary depending on several factors, including a candidate's qualifications, skills, experience, competencies, and geographic location. Some roles may qualify for extra incentives like equity, commissions, or other variable performance-related bonuses. Further details will be provided by our Talent Acquisition team during the interview process.

What You'll Get

At Billtrust, we believe your total rewards should reflect the impact you make. Our benefits package includes comprehensive health coverage, competitive retirement, generous PTO and parental leave, flexible work options, and meaningful investment in your professional development. We're building something special and we want you to feel supported while doing it.