Senior Software Engineer

Billtrust US Careers

6d•$129,000 - $172,000

About The Position

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.

Requirements

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

Nice To Haves

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

Responsibilities

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
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
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