Senior Full Stack Engineer (Realtime & Voice) Customer Experience Platform
Full Stack Engineer · Senior · Full Time · Remote
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Role
What you'll do.
Senior Full Stack Engineer anchoring Hopper's HTS Assist agentic AI assistant for travel, owning the realtime voice channel end-to-end across React/TypeScript frontends, Scala/Python backends, and GCP cloud infrastructure. You'll design multi-tenant systems, integrate CPaaS platforms like Twilio and Amazon Connect, orchestrate LLM-powered conversational AI, and ensure revenue-critical deployments maintain enterprise SLAs while mentoring senior engineers in a lean, high-ownership team environment.
Responsibilities
- Voice Channel Ownership: Own the voice channel end-to-end, including telephony and CPaaS integrations (Twilio, Amazon Connect), streaming speech-to-text and text-to-speech pipelines, realtime model orchestration, and defining latency and quality budgets for production systems serving enterprise partners.
- Full-Stack Feature Development: Build product features across the complete technology stack, including React/TypeScript web chat frontends, Scala and Python backend microservices, and GCP cloud infrastructure, ensuring seamless integration between conversational AI models and user-facing interfaces.
- Multi-Tenant Architecture Design: Design and maintain scalable multi-tenant systems that serve many travel partners through configuration-driven approaches rather than code forks, enabling rapid partner onboarding while maintaining system efficiency and security.
- Enterprise Safety and Compliance: Build the safety and compliance infrastructure enterprise partners audit, including content filtering guardrails, PII redaction integration points, and regulatory compliance mechanisms for handling sensitive traveler and booking information.
- Production Operations and Reliability: Keep revenue-critical deployments healthy through comprehensive observability, alerting infrastructure, incident response protocols, and SLA performance monitoring, ensuring 24/7 availability for customer service operations across multiple time zones.
- Platform Capabilities for Partner Integration: Build and document platform capabilities that forward-deployed engineers configure for partner telephony integrations and go-lives, enabling partners to customize voice flows, routing logic, and escalation workflows for their specific needs.
- Engineering Excellence and Mentorship: Raise the engineering bar through rigorous code review, architecture design reviews, technical mentoring of senior engineers, and establishing best practices for realtime systems, API design, and incident response within the team.
Qualifications
What we look for.
Technical
Full-Stack Software Engineering
6+ years of production software engineering experience with demonstrated senior-level ownership of large-scale systems, comprehensive full-stack capabilities spanning frontend, backend, infrastructure, and operational domains.
Realtime Systems Architecture
Hands-on experience building low-latency realtime systems such as voice applications, WebRTC/SIP protocols, streaming media pipelines, or comparable latency-sensitive products handling concurrent connections and high-throughput data flows.
Frontend Development
Production-level proficiency with React and TypeScript, building interactive interfaces, managing complex application state, handling real-time messaging and streaming data updates, and optimizing for performance and accessibility.
Backend Development
Deep backend experience with Scala or another JVM language (Java, Kotlin) and/or Python, building RESTful APIs, microservices architectures, event-driven systems, and handling concurrent request processing with proper error handling and resilience patterns.
Cloud Infrastructure and DevOps
Hands-on GCP or AWS experience including compute services (GCE, AppEngine, Lambda), managed databases, networking, CI/CD pipelines, containerization with Docker/Kubernetes, infrastructure-as-code, and cloud security best practices.
API Design and Microservices
Track record designing, building, and maintaining RESTful APIs with proper versioning and backward compatibility, microservices architectures with service discovery and inter-service communication, event-driven systems with message queues and event streaming.
AI/LLM Integration and Orchestration
Experience integrating and orchestrating large language models (LLMs) for conversational applications, including prompt engineering, token management, context window handling, and building robust fallback mechanisms for production reliability.
Operational Excellence
Operable-systems mindset with deep understanding of SLAs and error budgets, implementing comprehensive observability through metrics/logs/traces, designing alerting strategies, participating in on-call rotations, planning rollback strategies, and conducting incident postmortems.
Education
Computer Science or Related Field
Bachelor's degree in Computer Science, Software Engineering, Computer Engineering, or equivalent professional software engineering experience demonstrating the foundational knowledge required for complex system design.
Experience
Senior-Level Production Ownership
Demonstrated ability to own critical production systems end-to-end, making architectural decisions, managing technical debt, handling production incidents, and driving continuous improvement of system reliability and performance.
Voice or Realtime Communication Systems
Professional experience building or maintaining voice applications, telephony systems, WebRTC implementations, streaming audio/video processing, or other latency-critical systems where milliseconds significantly impact user experience.
Conversational AI and Speech Technologies
Working knowledge of speech-to-text engines (Whisper, Deepgram), text-to-speech systems (ElevenLabs, Google Cloud Text-to-Speech), LLM orchestration frameworks, and building multi-turn conversational experiences with natural language understanding.
CPaaS and Telephony Integration
Experience integrating with cloud communications platforms such as Twilio, Amazon Connect, Genesys, or LiveKit, including handling call routing, IVR flows, webhooks for call events, and managing stateful call sessions.
Enterprise Software Development
Experience building multi-tenant SaaS systems serving enterprise customers, implementing role-based access control, audit logging, data isolation, and managing complex customer-specific configurations and deployments.
Customer Service and Support Systems
Background developing customer service platforms, CRM systems, contact center software, workflow automation tools, or help desk applications, with understanding of customer support workflows and operational constraints.
Skills
Required
React
Production-level expertise building interactive user interfaces, component architecture, hooks-based state management, performance optimization, and integrating with backend APIs and real-time data streams.
TypeScript
Advanced TypeScript proficiency including generic types, advanced type inference, strict mode, type-safe API integration, and leveraging TypeScript for building maintainable large-scale frontend applications.
Scala
Production backend development in Scala, including functional programming patterns, akka actor model or alternative concurrency frameworks, type safety, and building high-performance microservices on the JVM.
Python
Fluent Python development for backend services, async/await patterns, REST frameworks (FastAPI, Flask), data processing, integration with machine learning libraries, and deployment in cloud environments.
GCP Cloud Platform
Hands-on experience with Google Cloud Platform services including Compute Engine, Cloud Run, Cloud Functions, Cloud SQL, Firestore, Cloud Storage, networking, IAM, and infrastructure monitoring.
Microservices Architecture
Design and implementation of distributed microservices systems including service boundaries, inter-service communication patterns, data consistency approaches, and operational challenges of distributed systems.
RESTful API Design
Designing and implementing well-structured REST APIs with proper HTTP semantics, versioning strategies, error handling, request/response formatting, authentication/authorization, and API documentation.
Observability and Monitoring
Experience implementing comprehensive observability through structured logging, distributed tracing, metrics collection, setting up alerting systems, dashboards, and using tools like Datadog, New Relic, or GCP Cloud Monitoring.
Docker and Container Orchestration
Containerizing applications with Docker, Kubernetes deployment and configuration, service mesh concepts, container image optimization, and managing containerized workloads in production environments.
CI/CD and Deployment Automation
Building and maintaining continuous integration and deployment pipelines, automated testing, blue-green deployments, canary releases, rollback automation, and infrastructure-as-code tools like Terraform or Pulumi.
Preferred
Speech-to-Text Integration
Nice to haveExperience integrating speech-to-text APIs such as Google Cloud Speech-to-Text, Deepgram, or OpenAI Whisper API, handling audio streaming, managing recognition confidence scores, and handling multiple language support.
Text-to-Speech Synthesis
Nice to haveExperience with text-to-speech systems including ElevenLabs, Google Cloud Text-to-Speech, Amazon Polly, or similar services, handling audio quality optimization, voice selection, and real-time audio streaming to clients.
LLM Orchestration and RAG
Nice to haveExperience building applications with large language models using frameworks like LangChain or LlamaIndex, implementing retrieval-augmented generation (RAG) patterns, prompt optimization, and managing LLM costs at scale.
Twilio Integration
Nice to haveWorking knowledge of Twilio's APIs for voice calls, SMS, WhatsApp, webhooks for call events, handling stateful call sessions, and building interactive voice response (IVR) systems.
Amazon Connect
Nice to haveExperience with Amazon Connect for building contact center solutions, routing logic, integrating with AWS Lambda for custom IVR flows, and managing customer service workflows at scale.
WebRTC and Real-Time Communication
Nice to haveUnderstanding of WebRTC architecture, peer-to-peer connections, media negotiation, bandwidth management, and building real-time audio/video applications with low latency requirements.
AI Code Assistants
Nice to haveProficiency using AI coding tools such as GitHub Copilot, Claude, or ChatGPT as integrated parts of development workflow, with strong judgment to review, test, and validate AI-generated code before production deployment.
Travel Industry Systems
Nice to haveFamiliarity with travel industry technologies including Property/Person Summary systems (PSS), Global Distribution Systems (GDS), hotel Property Management Systems (PMS), Central Reservation Systems (CRS), or travel booking workflows.
Genesys or LiveKit
Nice to haveExperience with Genesys cloud communications platform or LiveKit real-time communication platform for building scalable voice/video solutions.
Event-Driven Architectures
Nice to haveBuilding event-driven systems using message brokers like Kafka, RabbitMQ, or cloud-native event systems, implementing event sourcing patterns, and managing complex asynchronous workflows.
Compensation
Pay and benefits.
Base·USD 180,000 – 280,000
Full posting
Original listing.
About the Role
HTS Assist is Hopper's agentic AI assistant for travel, resolving flight changes, cancellations, refunds, and bookings over chat and voice for some of the world's largest travel brands. We're looking for a senior full stack engineer to anchor this product, owning the realtime and voice layer end to end while building across React/TypeScript front ends, Scala and Python services, and cloud infrastructure. The team is lean and senior, ownership is broad, and the path from your code to a traveler's phone call is short.
What would your day-to-day look like
Own the voice channel end to end, including telephony and CPaaS integrations (e.g., Twilio, Amazon Connect), streaming speech-to-text and text-to-speech pipelines, realtime model orchestration, and latency and quality budgets
Build product features across the stack, including web chat front ends in React/TypeScript, backend services in Scala and Python, and infrastructure on GCP
Design for multi-tenant scale, with one codebase serving many partners through configuration rather than forks
Build the safety and compliance plumbing enterprise partners audit, including guardrails, content filtering, and PII redaction integration points
Keep revenue-critical deployments healthy through observability, alerting, incident response, and SLA performance
Build the platform capabilities forward-deployed engineers configure for partner telephony integrations and go-lives
Raise the engineering bar through code review, architecture reviews, and mentoring
An ideal candidate has
6+ years of software engineering experience, with senior-level ownership of production systems and genuine full-stack range
Hands-on realtime systems experience, such as voice applications, WebRTC/SIP, streaming media, or comparable low-latency products
Strength in a modern front end (React, TypeScript) and depth on the backend (Scala or another JVM language, and/or Python), along with cloud infrastructure experience on GCP or AWS
A track record designing, building, and maintaining RESTful APIs, microservices, or event-driven systems
Familiarity using AI coding tools as a standard part of their workflow, with the judgment to review, correct, and own everything that ships
An operable-systems mindset, covering SLAs, observability, on-call rotations, and rollback plans
The ability to break down complex problems, make pragmatic tradeoffs, and ship iteratively, backed by strong communication across product, design, and operations
Bonus points for conversational AI or LLM orchestration experience, including speech technologies such as Deepgram, ElevenLabs, Whisper, or OpenAI Realtime
Bonus points for working knowledge of cloud telephony or CPaaS platforms such as Twilio, Amazon Connect, Genesys, or LiveKit
Bonus points for experience building customer service, CRM, contact center, or workflow automation tools
Familiarity with travel industry technologies (PSS/GDS, hotel PMS/CRS) is a plus, though not required
Perks and benefits of working with us
Well-funded and proven startup with large ambitions, competitive salary and the upsides of pre-IPO equity packages
Unlimited PTO
Carrot Cash travel stipend
Access to co-working space on demand through FlexDesk and a work-from-home stipend
Please ask us about our very generous parental leave, much above industry standards
Entrepreneurial culture where pushing limits and taking risks is everyday business
Open communication with management and company leadership
Small, dynamic teams, massive impact
100% employer-paid Medical, Dental and Vision coverage for employees
Access to Disability and Life insurance
Health Reimbursement Account (HRA)
DCA/FSA and access to a 401k plan
About Hopper
At Hopper, we are on a mission to become the leading travel platform globally, powering Hopper's mobile app, website and our B2B business, HTS (Hopper Technology Solutions). By leveraging massive amounts of data and advanced machine learning algorithms, Hopper combines its world-class travel agency offering with proprietary fintech products to bring transparency, flexibility and savings to travelers globally. We have developed several unique fintech solutions that address everything from pricing volatility to trip disruptions, helping people travel better and save more on their trips.
The Hopper platform serves hundreds of millions of travelers globally and continues to capture market share around the world. The Hopper app has been downloaded over 120 million times and has become largely popular among younger travelers, with 70% of its users being Gen Z and millennials.
While everyone knows us as the Gen Z and Millennial travel app, Hopper has evolved to become much more than that. In recent years, we've grown into a travel fintech provider, commerce platform, and global travel agency that powers some of the world's largest brands.
Through HTS, our B2B division, the company supercharges its partners' direct channels by integrating our fintech products on their sites or powering end-to-end travel portals. Today, our partners include leading travel brands like Capital One, Nubank, Air Canada, and many more.
Here are just a few stats that demonstrate the company's recent growth:
Billions of dollars worth of travel and travel fintech are sold through Hopper and HTS' channels every year.
Our fintech products, including Cancel for Any Reason and Flight Disruption Assistance, have exceptionally strong CSAT because the terms are always clear, and customers receive instant, no-questions-asked resolutions.
Almost 30% of our app customers purchase at least one fintech product when making a booking, and consumers are 1.6x more likely to repurchase if they add fintech to their booking versus if they booked just travel.
Given the success of its fintech products, Hopper launched a B2B initiative, HTS (Hopper Technology Solutions), which represents more than 75% of the business.
Through HTS, any travel provider (airlines, hotels, banks, travel agencies, etc.) can integrate and seamlessly distribute Hopper's fintech or travel inventory on their direct channels. As its first HTS partnership, the company partnered with Capital One to co-develop Capital One Travel, a new travel portal designed specifically for cardholders. Other HTS partners include Air Canada, Uber, CommBank, Nubank, Flair Airlines and many more.
Hopper has been named the #1 most innovative company in travel by Fast Company. Hopper has been downloaded over 120 million times and continues to have millions of new installs each month. Hopper is now the #3 largest online travel agency in North America and 70% of our app customers are Gen Z and millennial travelers.
Hopper has raised over $750 million USD of private capital and is backed by some of the largest institutional investors and banks in the world. HTS is primed to continue its growth as the leading travel ecommerce provider in a $1 trillion online shopping category. The Hopper app and website will also continue to be the preferred travel provider for Gen Z and Millennials.
Come take off with us!
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