Description

• 5+ years hands-on production experience with Twilio Programmable Voice, Twilio Studio, and TwiML — at enterprise scale (not just POC or sandbox)
• Deep, working knowledge of Twilio Studio Flow design: execution model, widget types, HTTP Request widget limitations, execution step limits, and the conditions under which Studio is and is not the right tool for a given problem
• Expert-level TwiML authoring and the interaction between TwiML verbs and Twilio's execution model under load
• Production experience with Twilio Webhook architecture: signature validation, async response patterns (to handle the 15-second hard timeout), status callbacks, recording callbacks, and idempotent webhook handlers
• Hands-on experience with Twilio TaskRouter: workspace design, Worker/Queue/Workflow configuration, EventStreams integration, and replicating complex routing criteria from legacy ACD systems
• Demonstrated experience designing DTMF fallback paths — handling fax tone detection (1100Hz), timeout/no-input retry loops, invalid-digit recovery, and graceful voicemail fallback under all failure conditions
• Production experience with ASR failure recovery: confidence threshold tuning, multi-modal fallback (speech → DTMF), language-specific grammar considerations, and latency management for STT under clinical call profiles
• Real-world knowledge of carrier redundancy patterns for Twilio: dual-carrier SIP trunking, geographic failover, DNS-based routing, and the operational differences between Twilio Elastic SIP and direct carrier interconnects — including patterns not in Twilio's public documentation

Required — Architecture & Engineering

• 3+ production Twilio migrations led from end-of-life on-premises telephony (Genesys, Cisco, Avaya, or equivalent) to Twilio-based cloud architecture — you have personally designed and delivered the target-state architecture, not just contributed to one
• Strong proficiency in .NET (C# / ASP.NET Core) for Twilio Voice API backend services: webhook controllers, TwiML response generation, Twilio SDK usage, and integration with Redis for call session state
• Experience designing and operating Redis-backed distributed state management for stateless webhook systems — specifically maintaining call context (ANI, DNIS, IVR selections, transfer history) across multiple webhook hops within a single call
• Familiarity with AWS audio serving patterns for IVR: S3 object hosting, CloudFront CDN configuration, cache-warming strategies, and pre-signed URL generation for HIPAA-compliant prompt file access
• Experience with multi-tenant IVR architecture at scale: 500+ simultaneous call flows, shared routing infrastructure, per-tenant configuration, and isolation patterns
• Strong understanding of SIP protocol fundamentals — SIP trunking, DNIS/ANI manipulation, SIP headers, SIP-to-PSTN bridging, and the relationship between Twilio's SIP domain and downstream CUCM/PBX infrastructure

Key Skills

Education

Any Gradute