Back-End Developer

We are looking for a passionate Back-End Developer to implement AI solutions aimed at achieving business goals (CLAi automates a multitude of business operations simple and complex alike. That includes
document reading, data entry, CRM management, calendar scheduling, and automated appointment booking.).

This role offers the opportunity to work on cutting-edge project and collaborate with a team of talented researchers and engineers in a stimulating and dynamic environment.

What you’ll do

• GraphQL APIs: Design schemas, resolvers, and gateways (Apollo Federation), enforce contracts, manage schema lifecycle (versioning, persisted queries), and mitigate N+1 with DataLoader.
• LLM integration: Orchestrate OpenAI and other providers (tool calling, guardrails, evals, cost controls), build prompt pipelines and caching.
• Email at scale (DKIM/SMTP/AWS SES):
  • Set up SES identities, DKIM signing, SPF/DMARC alignment.
  • Implement SMTP pipelines, retries, idempotency, and rate limiting.
  • Handle bounces/complaints via SNS → SQS, suppression lists, deliverability monitoring.
• Messaging & chat: Build reliable SMS flows (Twilio/Telnyx/SMPP), delivery tracking, and real-time chat (WebSockets/Event streams), search and threading.
• (Preferred) Voice automation: SIP/WebRTC basics, IVR/ASR/TTS; experience with FreeSWITCH/Asterisk is a plus.
• Horizontal scale & reliability: Stateless services on Kubernetes, partitioning, queues/streams (Kafka/RabbitMQ/NATS), back-pressure, circuit breaking, SLOs/on-call.
• Metrics & analytics: Instrument with OpenTelemetry; usage metering (e.g., OpenMeter); ship analytics dashboards (Metabase/Superset/ClickHouse/Timescale/Postgres).
  
   

Minimum qualifications

• 4+ years building production backends with Node.js + TypeScript.
• GraphQL expertise (NestJS/Apollo): schema design, federation, auth patterns, persisted queries/CDN caching.
• Hands-on LLM integration (OpenAI/Anthropic/Vertex, etc.).
• Email delivery with AWS SES + DKIM/SMTP and operational deliverability (SPF/DMARC, feedback loops).
• SMS integrations (Twilio/Telnyx/SMPP) and real-time systems (WebSockets/SSE/pub-sub).
• Strong RDBMS skills (PostgreSQL), plus Redis; testing (unit/integration), observability (logs/metrics/traces).
• Containers/Kubernetes, CI/CD, IaC basics.
  
   

Nice to have

• Voice/telephony: SIP/RTP/WebRTC, FreeSWITCH/Asterisk, ESL; STT/TTS/Whisper.
• Event-driven microservices, gRPC, and GraphQL Federation at scale.
• Analytics stack: ClickHouse/Timescale; embedded dashboards.
• Usage-based billing/metering, multi-tenant isolation, GDPR/PII handling.
• Vector search/RAG and embeddings.
  
   

Our stack (you don’t need all of it)

• Node.js, TypeScript, NestJS, GraphQL (Federation), REST (auxiliary), gRPC
• PostgreSQL/Timescale, Redis; ClickHouse
• Kafka/RabbitMQ/NATS
• Kubernetes (EKS), Terraform, Docker
• OpenTelemetry, Prometheus/Grafana, Loki
• OpenAI + other LLMs; Whisper/STT/TTS
• AWS SES (DKIM/SMTP), Twilio/Telnyx/SMPP, WebSockets