Senior Backend Engineer - Platform Architecture

What You'll Do Design and build a Customer Service, Product Catalog Service, Entitlement Service, and Onboarding Service that sit above our existing product services Migrate authentication off Bill Pay and onto Amazon Cognito, issuing JWTs that every downstream service trusts Introduce API Gateway as the single entry point for our React/Flutter frontends Move products off direct, synchronous service-to-service calls and onto event-driven communication using Amazon EventBridge and SQS Enforce a database-per-service pattern across MongoDB Atlas — no product reading another product's database directly Partner with product teams (Bill Pay, Travel, Spend, Early Wage) to onboard their services onto the new platform layer with minimal disruption Help plan and execute a migration Contribute to decisions on observability, logging, and auditing (CloudWatch, OpenSearch, CloudTrail) as the service count grows What We're Looking For 8 + years of backend engineering experience, with real ownership of production systems at scale Strong hands-on experience with AWS (ECS Fargate, EKS, or Lambda; API Gateway; EventBridge or SQS; S3; Secrets Manager) Experience with MongoDB (Atlas preferred) and designing schemas/collections for service boundaries, not just querying an existing one Experience with microservices or service-oriented architectures, including the tradeoffs of synchronous vs. event-driven communication Familiarity with authentication/identity systems (Cognito, Auth0, or equivalent) and JWT-based auth flows Comfort operating in a fintech environment — KYC flows, sensitive customer data, and the extra care that requires A track record of migrating or refactoring systems incrementally, in production, without halting feature work Nice to Have Experience building a platform layer for a multi-product company (shared identity/entitlements across otherwise independent products) Familiarity with React enough to collaborate closely with frontend teams consuming your APIs Prior fintech or lending/payments experience Experience with infrastructure as code (Terraform, CDK, or similar)