Senior Backend Engineer

About the Role: Every AI service, cloud provider, and SaaS tool generates billing data in its own special snowflake format. Someone needs to make sense of it. That someone is you.

As a Senior Backend Engineer, you’ll architect and build the systems that ingest and normalize cost data from OpenAI, Anthropic, and dozens of other vendors. Think of it as modern ETL—where the “E” stands for expensive cloud bills.

You’ll work at real scale, processing production data from some of the best engineering teams in the world. You’ll have significant ownership in shaping how we collect, transform, and deliver data that helps our customers understand and optimize their cloud spend, especially in this fast-evolving AI landscape.

You Will

• Design and build resilient billing adapters that remain stable, even when vendors break their APIs

• Transform inconsistent vendor data into clean, reliable internal models

• Integrate with a wide range of REST APIs, from well-documented to borderline hostile

• Write maintainable, production-grade Python code used in daily cost analysis pipelines

• Debug and support production systems that process millions in cloud spend daily

• Review code and collaborate with experienced engineers who care about quality and pragmatism

• Proactively improve internal tooling, observability, and scalability of backend systems

What You Bring

• Experience working with billing systems, FinOps tools, or cloud cost data

• Strong understanding of cloud provider APIs (AWS, GCP, Azure)

• Background in ETL/data pipelines and transforming unstructured inputs into structured outputs

• Experience working on SaaS platforms at scale

• Comfort navigating production incidents and delivering reliable, debuggable code

• Technical Skills

  • 4+ years of backend development experience

  • 2+ years in Python — You write clean, idiomatic code and understand performance tradeoffs

  • Strong SQL fluency — CTEs, window functions, and joins are in your toolbox

  • Solid experience with REST API integration, including pagination, auth, and rate limits

  • Familiarity with AWS services, especially Lambda, S3, and cost-related tooling

    • A working knowledge of data transformation best practices and schema evolution pitfalls

  • Proficiency with Git and version control workflows

  • A testing mindset — you write tests as a way to document and protect your work

• Professional Skills

  • Methodical problem solver with an eye for edge cases

  • Clear communicator who can explain systems and decisions to technical and non-technical teammates

  • Strong ownership mentality — you can take a project from concept to production

  • Comfortable adapting to changing APIs, priorities, and product direction

  • Collaborative and team-minded — you see code review as a place for shared learning

Please note: CloudZero is unable to sponsor employment visas or provide immigration-related support now or in the future. All candidates must have current, unrestricted authorization to work in the United States permanently.