Senior Full Stack Engineer (Realtime & Voice) Customer Experience Platform

Company: Hopper
Apply for the Senior Full Stack Engineer (Realtime & Voice) Customer Experience Platform
Location: London
Job Description:

Overview

In this role, you anchor HTS Assist, Hopper’s agentic AI for travel, owning the real-time voice layer end-to-end and delivering across web and backend services. You will work on telephony, CPaaS integrations, streaming speech pipelines, and latency-aware orchestration to support flight changes, cancellations, refunds, and bookings. You’ll collaborate with cross-functional teams to ship scalable features that power travel experiences for partners and customers. The role offers high ownership in a lean, senior team with meaningful impact on core travel workflows.

Pay / Benefits

  • competitive salary
  • pre-IPO equity benefits
  • health insurance through Vitality Health
  • Smart Pension contributions
  • generous parental leave
  • work-from-home stipend

Responsibilities

  • Own the voice channel end-to-end, including telephony integration and CPaaS (e.g., Twilio, Amazon Connect)
  • Develop and maintain streaming speech-to-text and text-to-speech pipelines
  • Build features across React/TypeScript front ends and Scala/Python backend services
  • Design for multi-tenant scale with a single codebase configured for partners
  • Implement safety, compliance, guardrails, content filtering, and PII redaction integration points
  • Maintain platform health via observability, alerts, incidents, and SLA adherence
  • Configure and support go-lives for partner telephony integrations
  • Raise engineering bar through code reviews, architecture reviews, and mentoring

Key requirements

  • 6+ years of software engineering with ownership of production systems
  • Hands-on realtime systems experience (e.g., voice apps, WebRTC/SIP, streaming media)
  • Strong frontend (React, TypeScript) and backend (Scala or JVM language, and/or Python) with cloud infra on GCP or AWS
  • Experience designing/maintaining RESTful APIs, microservices, or event-driven systems
  • Familiarity with AI coding tools and the ability to review and own shipped code
  • Operable-systems mindset: SLAs, observability, on-call rotations, rollback plans
  • Ability to break down complex problems, make pragmatic tradeoffs, and ship iteratively
  • Bonus: conversational AI/LLM orchestration, speech tech (Deepgram, ElevenLabs, Whisper, OpenAI) and cloud telephony/CPaaS platforms
  • Bonus: experience building customer service, CRM, contact center, or workflow automation tools
  • Bonus: familiarity with travel tech (PSS/GDS, hotel PMS/CRS)
  • strong communication across product, design, and operations
  • mentoring and code review leadership
  • pragmatic decision-making and prioritization
  • React/TypeScript
  • Scala
  • Python

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Posted: October 1st, 2026