Senior Backend Engineer

Suppli is a company focused on revolutionizing payments in the distribution industry. They are seeking a Senior Backend Engineer to architect and build systems that handle millions of transactions daily, integrate with ERP systems, and utilize LLM technology for enhanced revenue cycle management.

Responsibilities:

• High-volume payment processing systems and secure financial APIs
• Deep integrations with major ERPs (NetSuite, Sage, Acumatica, etc.)
• LLM-powered workflows (credit decisions, remittance matching, automated comms)
• Real-time data pipelines handling millions of financial records
• AR / collections automation that directly impacts customer cash flow

Requirements:

• 4+ years of backend experience with strong system design chops
• Expert-level Ruby on Rails (Rails 7+, Ruby 3+) — our core backend is modern Rails and you'll own huge parts of it from day one → Exceptional candidates with deep experience in Django, Laravel, Spring Boot, or similar who are excited to go all-in on Rails will be considered
• Advanced PostgreSQL (query optimization, large datasets, logical replication, etc.)
• Proven ability to design clean, versioned REST/JSON APIs
• Experience shipping and operating ETL/background-job heavy systems in production
• Built or maintained third-party integrations with enterprise software
• Real fintech, payments, or billing experience (Stripe, ACH, lockbox, etc.)
• Hands-on LLM integration or prompt engineering (bonus if you've shipped it to production)
• Previously worked at a Series A–C startup and loved the chaos