Callsexperts
Mon, 29 Sep 2025 22:59:49 GMT
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 includesdocument 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 doGraphQL 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 qualifications4+ years building production backends with + 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 haveVoice/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), TypeScript, NestJS , GraphQL (Federation) , REST (auxiliary), gRPCPostgreSQL/Timescale, Redis; ClickHouseKafka/RabbitMQ/NATSKubernetes (EKS), Terraform, DockerOpenTelemetry, Prometheus/Grafana, LokiOpenAI + other LLMs; Whisper/STT/TTSAWS SES (DKIM/SMTP) , Twilio/Telnyx/SMPP, WebSockets
