Senior Software Engineer - Business Systems

Self Financial is a venture-backed, high-growth FinTech company with a mission to increase economic inclusion and financial resilience by empowering people to build credit and build savings. We're looking for people who share our passion and are driven to tackle challenges, find solutions and make the financial space better for the communities we serve. Our team is passionate about challenging the status quo of the credit industry by providing people accessible tools to take control of their credit. Executing on our mission requires deep collaboration across our teams to ensure our products reach the people who can benefit from them the most, particularly the 100 million+ Americans who have no or low credit. About the Role We're looking for a Python engineer to join our Business Systems team, which builds and operates the integration layer connecting our core platforms (CRM, payments, and internal services) to the tools our customer-facing teams rely on every day. This is a high-traffic, latency-sensitive environment - our services handle hundreds of thousands of requests a day, and performance directly impacts the people using them in real time. Why Join Us You'll own real production performance problems backed by real data - not hypothetical scaling concerns. Our team recently completed a deep, evidence-based incident investigation that traced a latency issue down to specific code-level causes and shipped fixes that measurably cut error rates and response times. If you like solving concrete, high-impact problems and can back your reasoning with data, you'll fit right in. What You'll Do • Design, build, and maintain Python services (REST APIs) that integrate our CRM platform with downstream systems like payments, account management, and internal data services • Diagnose and resolve performance issues in production - including blocking I/O, connection handling, caching strategy, and API latency under load • Use async Python (asyncio) to safely parallelize I/O-bound work without degrading service throughput • Implement and tune caching layers (e.g., Redis) for high-throughput endpoints • Build and maintain integrations with a CRM platform (e.g., Salesforce), including data queries and REST-based sync • Deploy and operate services in a cloud environment (AWS or similar): serverless functions, containerized services, and monitoring/alerting • Use observability/APM tooling to trace requests, identify bottlenecks, and validate fixes with real production data • Write clean, well-tested, maintainable code following solid architectural patterns (clear separation of API, business logic, and infrastructure layers) • Participate in a rotating on-call/production-support role: triage alerts, coordinate fixes across teams, and help prevent incidents from becoming outages • Collaborate closely with other engineering teams, DevOps/SRE, and product stakeholders to scope and ship integration work What We're Looking For Required: • Strong professional experience with Python, including async programming and building/maintaining REST APIs • Solid understanding of data integration between services - how to reliably move, sync, and reconcile data across systems (batch or event-driven), handle failures/retries, and keep data consistent when systems disagree • Solid understanding of HTTP and API design (pagination, timeouts, rate limiting, caching), and experience debugging performance issues in a live service • Experience with a key-value or caching data store (Redis experience a plus) and comfort reasoning about caching/invalidation tradeoffs • Experience with at least one major cloud provider (AWS preferred) - serverless functions, containerized services, or similar • Comfort reading logs and distributed traces to debug systems