Senior Backend/Platform Engineer

Aircall•Town of Madrid, NY

About The Position

Aircall is a unicorn, AI-powered customer communications platform used by 22,000+ companies worldwide to drive revenue, resolve issues faster, and scale customer-facing teams. Weâre redefining customer communications by bringing voice, SMS, WhatsApp, and AI together into one seamless workspace. Our momentum comes from a simple idea: help teams work smarter, not harder. Aircallâs AI Voice Agent automates routine calls, AI Assist streamlines post-call work, and AI Assist Pro delivers real-time guidance so people can do their best work. The result is higher revenue, faster resolutions, and teams that scale with confidence. Aircall is headquartered in Paris, our European HQ, with a strong North American presence anchored in Seattle, our North American HQ, and teams across Madrid, London, Berlin, San Francisco, New York City, Sydney, and Mexico City. Weâve built a product customers love and a business thatâs scaling quickly, backed by world-class investors and driven by rapid AI innovation across multiple product lines. At Aircall, youâll join a company in motion. Weâre ambitious, product-driven, and execution-focused, with visible impact, fast decisions, and real growth. How we work at Aircall: Weâre customer-obsessed, data-driven, and focused on delivering meaningful outcomes. We value ownership, continuous learning, and thoughtful speed. If you thrive in a collaborative, fast-moving environment where trust and impact matter, youâll feel at home here. Within Aircall, we are launching a specialized New Product Unit to build the future of autonomous sales. We are improving the AI Orchestration Layerâa system that records and understands every customer interaction (calls, video, email, WhatsApp) to autonomously execute sales workflows: CRM updates, follow-ups, task creation, and coaching insights.Our long-term vision is to evolve this into a self-improving, agentic Sales OSâwhere specialized AI agents collaborate, coordinate, and continuously optimize the revenue process. The Role: We are looking for a Senior Backend & Platform Engineer to join us as our "Founding Platform Engineer." This is a unique, hybrid role where your impact is split: 50% Infrastructure/Platform (building the foundation, automation, and reliability) and 50% Backend Development (building core Python services and integrating them into our stack). You will be the bridge between the code we write and the environment where it lives, architecting the intelligence layer of a future autonomous Sales OS.

Requirements

5+ years of strong Backend Engineering experience, with a proven transition into or passion for Infrastructure and Tooling.
Advanced Python Expertise: Deep knowledge of async, typing, architecture patterns, and testing. You don't just write scripts; you write maintainable software.
Cloud & DevOps Mastery: Expert-level knowledge of GCP (or similar), Terraform, and Kubernetes.
System Architect: Experience designing scalable distributed systems and a solid understanding of software architecture principles.
Mindset: You are excited about building systems that reason and act, not just respond. You thrive in a fast-paced environment where ownership is real.
Communication: Fluency in English is required (Spanish is a plus). You must be able to sync effectively with stakeholders across Product, Design, and Business.

Responsibilities

Infrastructure as Code: Design and evolve our cloud architecture on GCP using Terraform.
Kubernetes Mastery: Own our K8s clusters, ensuring they are scalable, secure, and optimized for heavy AI workloads.
Observability Gold Standard: Design the strategy using Datadog, implementing the dashboards, SLIs/SLOs, and proactive alerting that provide deep visibility into our entire stack.
Developer Experience: Optimize CI/CD workflows and automated rollback strategies to ensure the team can ship fast without breaking things.
Backend Engineering: Design and implement production-grade Python services using Clean Architecture and Domain-Driven Design (DDD) principles.
AI Orchestration: Build and orchestrate LLM-powered agents (planning, reasoning, tool usage, memory) and integrate them with external SaaS systems (CRMs, dialers, OAuth providers).
AI-Augmented Workflows: Effectively use AI coding assistants to push the boundaries of what a lean, elite engineering team can ship.