Senior Backend Engineer

Simplify Alpha is seeking a Senior Backend Engineer for a next-generation, event-driven healthcare platform on AWS, designed for a high degree of autonomous (touchless) transaction processing. You will lead the design and delivery of Python/FastAPI microservices on AWS EventBridge, own AI agent integration, prompt iteration, and evaluation for your assigned services, and mentor mid-level engineers in a fast-moving, milestone-gated sprint.

Required Qualifications

• 7+ years of backend engineering experience with a track record of shipping production systems; Python strongly preferred.
• Hands-on experience building with LLMs agent design, prompt engineering, structured output, and tool / function calling including multi-step agent orchestration, RAG / knowledge-base grounding, confidence-based escalation, and evaluating prompt changes against replayable test scenarios.
• Deep expertise in FastAPI (or an equivalent async framework) and event-driven microservice design.
• Strong AWS experience: EventBridge, ECS Fargate, Lambda, RDS PostgreSQL, and DynamoDB.
• Event-driven architecture depth: at-least-once delivery, idempotency, dead-letter handling, and saga patterns.
• PostgreSQL: schema design, constraint authoring, and index strategy.
• Ability to own services end-to-end in a fast-moving, milestone-gated sprint without hand-holding.
• Demonstrated ability to mentor engineers and lead technical discussions.
• Practical experience leveraging an agentic AI platform (e.g. Claude Code, Cursor, GitHub Copilot Agents) across the software development lifecycle, with the ability to integrate AI-assisted workflows into team practices for coding, testing, review, and delivery.