Senior Software Engineer

Who We Are Finance leaders choose Billtrust to get paid faster, control costs, and maximize customer satisfaction. As the leader in B2B accounts receivable workflow and payment software, we provide the world’s leading brands with AI-powered solutions across the full AR lifecycle—from invoice presentment and payment processing to cash application and collections. With over 2,600 global customers, more than $1 trillion in invoice dollars processed, and a proprietary network of 13 million buyers, Billtrust delivers business value through deep industry expertise and a culture relentlessly focused on meaningful customer outcomes. We’re an AI-first company, not just in what we build for our customers, but in how we work. Across every function, our teams use AI tools daily to work faster, make better decisions, and deliver higher-quality outcomes. We hire exceptional people, give them cutting-edge AI capabilities, and measure success by the impact they create. If you want to do the best work of your career at the frontier of AI and fintech, Billtrust is the place to do it. Our Values Customers We relentlessly increase value for customer and do the right thing for them. Action We make ‘thoughtfully fast’ decisions, act quickly, cut through red tape, deliver progress not perfection, take ownership and accountability. Team Spirit We put the team ahead of ourselves, foster trust and respect, collaborate with passion, despise toxic politics, value our differences, and celebrate together. Innovation We challenge the status quo, experiment thoughtfully, and are novel and brilliant in what we create. Excellence We love to win, but we hate losing even more. We aspire to be the best and take pride in our work. When we fall short, we own it and come back stronger. Software Engineer, PHP The Software Engineer designs solutions and delivers backend features for our product platform using AI tools throughout the development lifecycle. As part of a small collaborative pod, this position is accountable for features end-to-end—leveraging AI assistance for specification, implementation, quality validation, deployment, and post-deployment support while ensuring quality outcomes at each stage. This is primarily a backend role focused on high-throughput data ingestion, PDF processing, and working with large datasets. The Software Engineer interfaces with Technical PMs and fellow engineers to deliver scalable, performant services with high velocity. This position also helps evolve our Al-assisted development practices and mentors Associate Engineers on effective AI tool usage. What You’ll Do Job Responsibilities Own specification quality for assigned features by ensuring specifications are complete, unambiguous, and include acceptance criteria and edge cases. Collaborate with Technical Product Managers (PMs) to translate product requirements into detailed technical specifications. Use AI coding tools (e.g., Claude Code) to generate implementations from technical specifications. Design and build data ingestion pipelines capable of reliably processing large volumes of structured and unstructured data. Implement PDF parsing, extraction, generation, and manipulation capabilities for high-volume document workflows. Design performant, memory-efficient software that scales efficiently with increasing data volumes while adopting a DevOps mindset. Review AI-generated code and peer contributions for correctness, security, performance, and architectural alignment. Validate AI-generated tests and ensure comprehensive test coverage. Design and implement REST APIs following established architectural patterns. Optimize database queries, schemas, and storage strategies for large relational datasets. Mentor Associate Engineers on effective AI tool usage and specification writing techniques. Share technical knowledge and best practices with the engineering team. Contribute to the evolution of AI-assisted development practices, including specification templates, prompt pat…