Billie

Senior Software Engineer (Payments) (f/m/d)

Berlin, Remote. Posted 16 days ago

The role

You will design, develop, test, deploy, maintain, and improve software for the Payments domain. This involves managing complex money flows between merchants, buyers, investors, and Billie using Kotlin and PHP systems.

What you will do

  • Design, develop, test, deploy, maintain, and improve software
  • Understand, modify, and debug complex business flows in Kotlin and PHP
  • Take part in incident response and own RCA follow-ups
  • Work with the Staff Engineer and architecture group on incremental plans
  • Write technical specifications for new features
  • Use AI agentic coding tools in daily work
  • Review code and mentor less experienced engineers
  • Represent the team with stakeholders and help with interviewing
  • Perform significant hands-on coding

Required qualifications

  • 5+ years of solid practical engineering experience
  • Proven experience putting Kotlin or Java-based solutions built on Spring into production
  • Experience building and running microservices in cloud-based environments
  • Hands-on experience with AI agentic coding tools and spec-driven development on production work
  • Ability to argue for and against architectural decisions using trade-off analysis
  • Experience working in a product-focused environment
  • Interest in understanding business finance and money movement
  • Experience with TDD, pair or mob programming, and continuous delivery
  • Clear communication with technical and non-technical audiences
  • Commitment to continuous learning
  • Good working understanding of domain-driven design

Nice to have

  • Kotlin
  • Apache Kafka
  • Flink
  • Beam
  • stream processing
  • reactive streams

Benefits

  • Virtual Shares Incentive Program
  • Flexible work hours
  • Hybrid working approach (up to 3 days per week from home)
  • 30 days vacation per year
  • Sabbatical opportunities
  • Extra child sickness leave for parents
  • Discounted access to Berlin Public Transport (BVG), Deutschland-Ticket, or JobRad
  • Annual development budget
  • Free German group classes
  • Company and team events, interest groups, run club, and game nights

About the company

Billie is a provider of Buy Now, Pay Later (BNPL) payment methods for businesses, offering B2B companies digital payment services and modern checkout solutions. They are a deep-tech company building financial products using proprietary, machine-learning-supported risk models.