Senior Backend Engineer

Senior Backend Engineer San Francisco
San Francisco CA United States Full-time On-site

Own backend systems where a bug doesnt just break a feature it touches real money moving through real credit decisions.

What youd actually work on

• Building and owning production backend systems for core payments and credit workflows using TypeScript and end to end
• Designing APIs services data models and contracts that other teams (data science risk product) depend on daily where good enough stops being good enough once real transactions are on the line
• Creating internal tools that let non-engineering teams review decisions trace data lineage and move faster without pinging an engineer every time something looks off
• Taking ambiguous loosely defined problems and turning them into shipped production-grade slices rather than waiting for a fully scoped ticket
• Improving reliability and latency on systems where downtime or a bad edge case has a direct visible cost not just a Slack complaint
• Working cross-functionally with risk and data science to define what data actually needs to look like before it hits a decisioning model
• Owning the full lifecycle from architecture decisions through to production support not handing off after the first deploy

Where it gets technically interesting

• A TypeScript and backend where correctness isnt optional. This stack directly powers payment and credit decisions so tradeoffs get scrutinized differently than in a typical SaaS product
• Serverless architecture on AWS (Lambdas) which means thinking hard about cold starts statelessness and failure isolation rather than defaulting to a monolith
• A PostgreSQL data layer feeding into Snowflake for downstream analytics and modeling so schema decisions have consequences well past your own service
• Designing systems and data contracts from close to zero: the infrastructure is still being defined so youll shape patterns other engineers will follow not just extend someone elses work
• Close regular collaboration with a data science team turning your APIs and data pipelines into production ML-driven decisions which raises the bar on what clean data actually means
• Real production stakes from day one: the systems you touch are already live with paying enterprise customers not waiting on a future launch

What were looking for

• 5 to 12 years of backend engineering experience including real production ownership not just feature work inside someone elses system
• Strong hands-on experience with TypeScript in production plus solid SQL and relational database skills
• Direct experience in payments fintech or credit and risk systems ideally at a fast-growing VC-backed company
• Comfort with AWS serverless architecture (Lambdas) and designing for reliability at scale
• A track record of owning a project or product area end to end: defining the problem proposing the approach shipping it and iterating
• Experience collaborating across risk data science and engineering not just within a single teams boundaries
• Bonus: Python proficiency and experience with data pipelines ETL or Snowflake

The company

An AI-native fintech company building credit and payments infrastructure for B2B commerce backed by top-tier venture investors with $250M raised to date. A lean engineering team of around 30 to 40 people already powering payment and credit workflows for enterprise customers in live production not in beta. This role sits close to the founding team and works directly with risk and data science on some of the companys highest-stakes systems.

Compensation: $170000 to $250000 base plus competitive equity
Languages: English (fluent professional)

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