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/Type Script 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 CPaa S 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/Type Script, 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 idóneo 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, Web RTC/SIP, streaming media, or comparable low-latency products Strength in a modern front end (React, Type Script) and depth on the backend (Scala or another JVM language, and/or Python), along with cloud infrastructure experience on GCP or AWS A track re

📌 Senior full stack engineer (Madrid)
🏢 Hopper
📍 Madrid