Senior Backend Engineer

Cassi Home

1d

About The Position

Cassi is a fast growing startup building an intelligent home automation platform that enables property managers, service providers, and homeowners to easily maintain and operate a property (and more). We're a small team shipping real product daily — SOC2 compliant, event-driven, and built to scale.

Requirements

• 5+ years of professional full-stack development experience
• TypeScript mastery: comfortable with branded types, generics, strict mode, and the type system as a design tool.
• Backend depth: Experience with DDD, event-driven architecture, or clean architecture patterns. Understanding of why service boundaries matter.
• Database fluency: Comfortable with both NoSQL (DynamoDB) and relational (PostgreSQL). Ability to model data for the access pattern.
• API design: RESTful API design with proper error handling, validation, and documentation. Experience with OpenAPI/Swagger.
• Payments/billing experience: Integrated with payment processors and understand edge cases — idempotency, reconciliation, refunds, ledger accuracy.
• Move fast, ship quality: Ability to take a feature from concept to production in days. Testing is a first class citizen. Build for today, architect for tomorrow.

Nice To Haves

• Real-time communication systems (WebSocket, SSE, WebRTC)
• AWS services experience (SQS, SNS, Lambda, SES, DynamoDB)
• Multi-tenant SaaS architecture
• SOC2 compliance awareness
• Experience at a small company where you owned features end-to-end
• Team leadership or tech lead experience

Responsibilities

• Take primary ownership for a couple verticals and contribute across all of them: Voice & Chat Infrastructure, Billing & Payments, Communications Layer, Service Provider Workflows, Platform Features.
• Drive features from design through production.
• Own problem spaces, make architectural decisions, and lead by example.
• Build services, not just endpoints.
• Integrate with payment providers.
• Handle errors and think about failure modes.
• Write thorough, scalable and clear documentation.

What This Job Offers

• Job Type: Full-time
• Career Level: Senior
• Education Level: Associate degree