Job Title

Voice AI Scheduling (Scale‑Ready, Multi‑Tenant) — Remote Company:Apex Dental Systems Location:Remote (must overlap7+ hourswith 8am–5pm Pacific / America‑Vancouver) Type:Full Time Engineer with ramp up into CTO Compensation: Engineer: $2000USD/month + 1% equity Upon promotion to CTO: $4000USD/month + 2% equityAbout Us Apex Dental Systems builds voice AI reception for dental/orthodontic clinics. We connect real phone calls (Retell AI + telephony) tobooked appointmentsviaNexHealthand, over time, direct PMS connectors. We’re moving from pilot toscale across 50–100+ clinicswith high reliability and tight cost control. The Mission Own thescale‑ready backend platform : multi‑tenant onboarding automation, secure configuration management, rate‑limit and retries, SLO‑backed reliability, cost observability, and compliance (HIPAA/PIPEDA). Your work allows us to onboard dozens of clinics per week withminutes, not days , of setup.Outcomes You’ll Deliver in the First 4–6 WeeksMulti‑tenant architecturewith tenant isolation, role‑based access (RBAC), and per‑clinic secrets (env‑less runtime or AWS Secrets Manager). Onboarding automationthat reduces per‑clinic setup to≤60 minutes : provider/location/appointment‑type sync, ID mapping, test calls, and health checks. Hardened tool endpointsused by the voice agent (Retell function calling): availability_search, appointment_book, appointment_reschedule, appointment_cancel, patient_find_or_create, note_create, warm_transfer. Reliability controls : idempotency keys, timeouts, retries with backoff, circuit breakers; graceful fallbacks + warm transfer. Observability & SLOs : structured logs, metrics, tracing; dashboards forp50/p95 latency , error rates, booking success %, transfers, cost per minute/call; alerts to Slack. Security & compliance : PHI minimization, at‑rest and in‑transit encryption, access logging, data‑retention policy, BAA‑aware configuration. Cost guardrails : per‑tenant budget meters for voice minutes/LLM/TTS usage and anomaly alerts. KPIs you’ll move: Median tool‑call latency(p95≥ 80%booking/reschedule success without human handoff (eligible calls) 99.9%+middleware availability tool‑level error rate (after retries) ≤ 60 mintime‑to‑onboard a new clinic (target30 minby week 6)ResponsibilitiesDesign, implement, and documentmulti‑tenantREST/JSON services consumed by the voice agent. IntegrateNexHealthnow; design extension points fordirect PMS(OpenDental/Dentrix/Eaglesoft/Dolphin) later. Buildsync jobsto keep providers/locations/appointment types up‑to‑date (with caching via Redis, invalidation, and backfills). Implementidempotent booking flowswith conflict detection and safe retries; log every state transition. Stand upobservability(metrics/logs/traces) and alerting; defineSLOs/SLAand on‑call basics. ShipCI/CDwith linting, tests (unit, contract, integration), and minimal load tests. Enforcesecrets management , least‑privilege IAM, and a cleanaudit trail . Partner with our conversation designer to refine tool schemas and edge‑case flows (insurance screening, multi‑location routing). Mentor a mid‑level engineer and coordinate with ops for smooth rollouts. Minimum Qualifications5–8+ yearsbuilding production backend systems (you’ve owned a system in prod). Expert inNode.js (TypeScript)orPython(FastAPI/Nest/Express). Deep experience withexternal API integrations(auth, pagination, rate limits, webhooks). Postgres(schema design, migrations) andRedis(caching, locks). Production reliability patterns: retries/backoff, timeouts,idempotency , circuit breakers. Observability: metrics, tracing, log correlation; incident triage. Security/compliance mindset; comfortable handling sensitive data flows. Strong written English; crisp architectural docs and PRs. Nice‑to‑HaveRetell AI (or similar voice/LLM with function calling and barge‑in),Twilio/SIP . NexHealth or other healthcare scheduling APIs; PMS/EHR familiarity. HIPAA/PIPEDA exposure, SOC 2‑style controls. OpenTelemetry, Prometheus/Grafana, Sentry; AWS/GCP; Terraform; Docker/Kubernetes. High‑volume, low‑latency systems experience. Our Stack (target)Runtime:Node.js (TypeScript)orPython (FastAPI) Data:Postgres, Redis Infra:AWS (ECS/EKS or Fargate), Terraform, GitHub Actions Integrations:Retell AI (voice), NexHealth (scheduling), Twilio/SIP (telephony) Observability:OpenTelemetry + Prometheus/Grafana or Cloud provider equivalents How We WorkRemote‑first; async‑friendly;4+ hoursoverlap with Pacific time. Code in company repos,NDAs/PIAs/BAAs , DCO/CLA, and strict access hygiene. We optimize for reliability and patient privacy over quick hacks. Interview Process (fast, 7–10 days)Intro (20–30 min):Your background, past scale/reliability wins. Take‑home (90 min, paid for finalists): Implement availability_search + appointment_book against a stubbed NexHealth‑like API. Include idempotency keys, retries with backoff, timeouts, and basic tests. Provide a shortrunbookand adashboard sketchfor p95 latency & error‑rate alerts. Deep‑dive (60 min):Review your code; discuss multi‑tenant design, secrets, SLOs, and cost control. Final (30–45 min):Collaboration & comms. How to Apply Emailinfo@with subject“Senior Backend — Scale‑Ready Voice AI”and include: CV + GitHub/portfolio 5–10 lines on a system you mademulti‑tenant(what changed?) A time you preventeddouble bookingsor handled idempotency at scale Your preferred stack (Node+TS or Python), availability, and comp expectations