Solution Architect (Twilio Platform Expertise)

Role: Senior Solution Architect

REMOTE ROLE

Key Skills:

Twilio Platform Expertise, .NET (C# / ASP.NET Core), AWS, Healthcare Domain

Client is seeking a

Principal Voice Platform Engineer

to serve as our primary subject matter expert (SME) for Twilio-based telephony architecture on enterprise healthcare communication programs. This is a senior individual-contributor and technical leadership role — you will not just build systems, you will

define the architecture

that all migration engineers follow.

You will be the go-to expert for designing, validating, and governing Twilio Voice SDK, Twilio Studio, WebHooks and TwiML orchestration solutions at scale — including patterns and techniques that go well beyond what is documented in Twilio's public SDK guides. Your work directly enables healthcare organizations to migrate off end-of-life telephony infrastructure (Genesys PureConnect, Cisco, Avaya) onto modern cloud-native Twilio\+.NET platforms without clinical disruption.

Why This Role Exists:

Our healthcare clients cannot afford to discover architectural mistakes in UAT or production. This role is the insurance policy — someone who has already hit the edge cases, knows the undocumented platform limits, and architects solutions that work at the first clinical go-live.

What You'll Do

Architecture \& Design (Primary)

• Own the end-to-end Twilio platform architecture for healthcare communication migration programs, including inbound call path design, Studio Flow topology, TwiML webhook orchestration, and carrier-layer configuration
• Define and enforce the

"Thin Studio, Smart API"

architectural pattern — governing which logic lives in Twilio Studio vs. the .NET Voice API backend — across all delivery teams

• Design the shared infrastructure services that all milestone teams consume: Redis-backed Call Session Store, CloudFront CDN audio serving, carrier redundancy configurations, and Twilio webhook reliability patterns
• Architect Twilio solutions for complex multi-tenant IVR systems with 500\+ simultaneous call flows, including multi-level DTMF menus, ASR (speech recognition) workflows, on-call routing chains, and call transfer sequences
• Design and document DTMF fallback paths, ASR failure recovery strategies, and carrier redundancy patterns appropriate for 24/7 healthcare-grade production environments
• Produce Architecture Decision Records (ADRs) for all significant platform decisions, with explicit documentation of trade-offs, alternatives considered, and healthcare-specific constraints

Technical Leadership

• Lead the M0 AI Architectural Analysis sprint on migration programs — driving handler-to-architecture mapping, Studio/API boundary definition, and call flow dependency graph production
• Conduct weekly architecture reviews with delivery teams, validating implementation against established patterns and catching deviations before they reach staging
• Mentor .NET engineers on Twilio SDK patterns, webhook idempotency, stateless TwiML generation, and the operational differences between Twilio Studio and programmatic Voice API approaches
• Review all Twilio-related pull requests as technical lead — checking for correctness against clinical load profiles, platform limits, and production reliability requirements
• Define and own the NFR (non-functional requirement) story set for each engagement: webhook response SLA gates, load test acceptance criteria, CDN warm-up procedures, and carrier failover validation

Client Engagement

• Present client's independent architectural recommendations to customer engineering and executive teams — clearly articulating trade-offs between platform approaches and the risks of common anti-patterns
• Lead story elaboration workshops for Twilio-heavy initiatives, co-authoring acceptance criteria with customers and ensuring architectural considerations are captured in backlog stories before development begins
• Serve as the client voice in customer architecture reviews, RFP responses, and proposal technical sections — representing client's SME depth on Twilio Voice and healthcare communications

What We're Looking For

Required — Twilio Platform Expertise

• 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

Required — Healthcare Domain

• Healthcare communications experience

— you understand the unique requirements of clinical telephony: on-call escalation chains, provider routing (not just ACD), clinical SLA expectations, and the patient safety implications of call routing failures

• Working knowledge of

HIPAA requirements

as they apply to telephony: PHI in call metadata, call recording consent workflows (HITECH), audit trail requirements, and the difference between a HIPAA-compliant architecture and a compliant implementation

• Experience designing for

24/7 mission-critical uptime

in clinical environments — where a routing failure is not a business inconvenience but a potential patient safety event

Nice to Have

• Experience with

Genesys PureConnect (ININ)

XML handler reverse-engineering or decommission

• Twilio Flex

and TaskRouter agent desktop configuration experience

• Twilio Voice Intelligence

or NLP-based intent routing (Twilio ConversationRelay, Autopilot, or custom ASR models)

• Twilio Notify

at scale — including rate limit architecture, priority queue dispatching, and mass-notification burst handling

• Experience with

number porting at scale

(10k\+ DID/toll-free numbers) including AT\&T/Twilio porting coordination and FOC management

• Hangfire

or equivalent .NET background job orchestration for asynchronous notification dispatch

• Experience building

automated regression test frameworks

for call flows — DTMF/ASR simulation, TwiML response assertion, CI/CD integration

• AWS Lambda / CloudFront / S3 operational experience in a production IVR audio serving context
• Familiarity with

Twilio Event Streams

and real-time operational dashboarding for call center/IVR observability

• Prior experience in a

vendor/consulting SME role

— presenting architectural recommendations to customer technical and executive stakeholders

Skills Overview:

Core Requirements:

• Twilio Voice SDKTwilio Studio FlowsTwiML AuthoringTwilio WebhooksTwilio TaskRouter.NET 8 / C#ASP.NET CoreRedis Session StateDTMF/ASR Fallback DesignCarrier RedundancySIP Trunking Healthcare IVR Architecture HIPAA Compliance Multi-tenant IVR at Scale

Preferred:

Twilio FlexTwilio NotifyVoice Intelligence / NLPTwilio Event StreamsNumber Porting OperationsHangfireCall Flow Regression TestingAWS CloudFront / S3

Domain Context:

Genesys PureConnect / ININOn-Call Routing ChainsClinical Communication PlatformsLegacy PBX MigrationCall Recording / HITECHHospital Communication Systems