[Hiring] Senior Software Engineer @Billtrust US Careers

Role Description

The Sr. Software Engineer is a critical role responsible for designing solutions and delivering complex features across our product platforms. You will leverage AI tools and co-worker agents such as Claude Code to specify, implement, validate, deploy, and support features end-to-end, focusing your expertise on architectural judgment, code quality, and mentorship.

As a senior member of a domain-aligned cohort, this position contributes deep expertise to the cohort’s product domain and interfaces with the Engineering Manager, Product Manager, and fellow cohort members to deliver scalable SaaS products with high velocity. You’ll drive the evolution of AI-assisted development practices, mentor engineers within the cohort on effective AI tool usage, and share knowledge across cohorts.

What You’ll Do

• Specification & Technical Collaboration
  • Own end-to-end specification quality for complex features, ensuring specs are comprehensive, unambiguous, and address all edge cases and non-functional requirements.
  • Collaborate with the Product Manager to translate complex product requirements into detailed technical specifications.
  • Lead technical decisions and contribute to domain expertise within your cohort.
  • 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 improvements to AI-assisted development practices within your cohort, including spec templates, prompt patterns, and validation workflows.
• Software Design, Delivery & Mentorship
  • Design performant software with a DevOps mindset that will scale as our volumes increase, and design and implement REST APIs following established patterns.
  • Support and maintain both UI and backend services within your cohort’s domain.
  • Mentor engineers within your cohort on effective AI tool usage, spec writing techniques, and code review practices, and share knowledge and experience across your cohort and with other cohorts.

Qualifications

• 5+ years of relevant software engineering experience designing and implementing scalable SaaS software.
• Bachelor’s degree in Computer Science (or equivalent experience), along with a firm understanding of data structures and scalable software design.
• Strong ability to write code in C#, C++, PHP, Java, Node.js or a similar high-level language.
• Proven ability to code/support HTML5, CSS/Sass, Angular, React, TypeScript/JavaScript, and other web technologies, with the ability to design and implement REST APIs.
• Strong understanding of SQL and relational databases, such as SQL Server or MySQL.
• 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 experience mentoring engineers and working closely with Product Managers, cohort members, and cross-functional teams.
• Well-honed skills in source control management using Git or similar.

Requirements

• Experience with spec-driven, agentic AI workflows where engineers delegate autonomous tasks to AI tools and provide guidance and oversight.
• Knowledge of NoSQL data stores, such as MongoDB or DynamoDB, and experience with AWS, Azure, or a similar cloud platform.
• Understanding of testable application design principles.
• Experience leading development process improvements or workflow optimization, with a track record of driving adoption of new tools or practices across teams.

Benefits

• Comprehensive health coverage.
• Competitive retirement plans.
• Generous PTO and parental leave.
• Flexible work options.
• Meaningful investment in your professional development.