Senior Backend Engineer (Contract)

About Us

At Sully.ai, we’re building cutting-edge AI-native infrastructure to power real-time, intelligent healthcare applications. Our team operates at the intersection of high-performance computing, ML systems, and cloud infrastructure — optimizing inference pipelines to support next-generation multimodal AI agents. We're looking for a deeply technical Senior Backend Engineer who thrives at the systems level and loves building performant, scalable infrastructure.

About the Project

Our client is a prominent outpatient behavioral health organization delivering psychiatry, counseling, and interventional services like TMS both in‑clinic and via telehealth. They operate multiple locations offering medication management for all ages, evidence‑based therapy modalities, and same‑day appointment options.

Patients use a secure web portal to access health records, message providers, request medication refills, and schedule appointments. New patients can request visits online and receive follow‑up within one business day. The staff dashboard must enable clinicians to review patient charts, manage AI‑generated notes, and oversee treatment workflows in a HIPAA‑compliant environment.

• Integrate with external systems—EHR platforms (via FHIR/HL7), telehealth providers, billing services, and authentication gateways—to enable seamless data exchange.
  

• Collaborate with front‑end developers—define shared TypeScript interfaces and ensure strict type safety across client and server domains.
  

• Implement—rigorous security, monitoring, and auditing measures to maintain HIPAA compliance and protect patient data.
  

• Design & Develop APIs: Create and maintain RESTful and GraphQL endpoints to support both patient‑facing and staff dashboards.
  

• Service Architecture: Build scalable, fault‑tolerant microservices using Node.js, ensuring low‑latency orchestration of AI agent tasks.
  

• Third‑Party Integrations: Implement secure data integrations with EHR systems (FHIR/HL7), payment gateways, OAuth/SAML providers, and other healthcare APIs.
  

• Data Modeling & Storage: Define and optimize schemas in PostgreSQL or MongoDB, manage migrations, and ensure efficient query performance.
  

• Security & Compliance: Enforce API security best practices (authentication, encryption, rate‑limiting) and HIPAA‑aligned audit logging.
  

• Testing & Documentation: Write comprehensive automated tests (unit, integration) and maintain up‑to‑date API documentation.
  

• Collaboration & Mentorship: Partner with front‑end, DevOps, and AI research teams; conduct code reviews; share knowledge of backend and integration patterns.
  

• 5+ years building production‑grade APIs and microservices with Node.js/Express or equivalent.

• Strong TypeScript expertise, including interface design and generic types for cross‑service contracts.

• Data Integration Experience: Proven track record integrating with external APIs and data streams (e.g., FHIR/HL7, OAuth, JSON/XML feeds).

• Database Proficiency: Hands‑on experience with relational (PostgreSQL) and/or NoSQL (MongoDB) databases, schema design, and performance tuning.

• Security & Compliance: Familiarity with API security mechanisms and regulatory requirements for healthcare data (HIPAA, encryption, audit trails).

• Communication Skills: Excellent verbal and written communication for collaborating in a distributed, cross‑functional team.
  

This is for someone who:

• Loves building from 0 to 1 (and then to 100).

• Can think in systems and move fast in chaos.

• Gets excited about real AI impact saving lives.

• Wants real ownership, is self driven and self-managed.
  

Why Sully?

👏 Team from OpenAI, DeepMind, NASA, GoogleX, Tesla, and 2 physicians: 6 exits, 2 IPOs.

🔥 Our model outperforms Claude, Gemini, and GPT-4.5 on clinical benchmarks.

📈 400+ healthcare orgs signed in 16 months.

⚡️ $25M raised from YC, Sequoia scouts, and more.

🌎 $1T+ market opportunity. We’re going after all of it.

Sully.ai is an equal opportunity employer. In addition to EEO being the law, it is a policy that is fully consistent with our principles. All qualified applicants will receive consideration for employment without regard to status as a protected veteran or a qualified individual with a disability, or other protected status such as race, religion, color, national origin, sex, sexual orientation, gender identity, genetic information, pregnancy or age. Sully.ai prohibits any form of workplace harassment.