Senior Software Engineer, Backend (Python)

Within Aircall, we are launching a specialized New Product Unit to build the future of autonomous sales. We are improving the AI Orchestration Layer—a 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 OS—where specialized AI agents collaborate, coordinate, and continuously optimize the revenue process.

The Role

We’re looking for a strong Senior Python Engineer who’s eager to go beyond traditional backend development.

This role is for someone ambitious—someone who takes pride in building things well, but knows how to move fast in a startup environment. You strike the right balance between clean architecture and pragmatism, between perfection and progress.

You’re energized by hard technical problems—distributed systems, AI orchestration, architectural trade-offs, performance, and scalability. You can go deep when needed, but you’re equally focused on shipping, learning, and iterating quickly.

You’re curious by nature, committed to continuous improvement, and excited to bring the most effective modern approaches—whether agentic patterns or AI-augmented development workflows—into real-world production.

This isn’t just another engineering role. It’s an opportunity to help build the intelligence layer behind a next-generation autonomous Sales OS.

What You’ll Do

Design and implement production-grade Python services with clean architecture and strong engineering discipline.

Architect scalable, distributed systems using Domain-Driven Design (DDD) principles.

Integrate with external SaaS systems (CRMs, dialers, meeting tools, OAuth providers).

Optimize performance, latency, cost, and reliability of AI-driven systems.

Build and orchestrate LLM-powered agents (planning, reasoning, tool usage, memory).

Develop internal frameworks to manage:

Agent coordination

Tool execution

Memory layers

Event-driven workflows

Work closely with AI engineers, product, and founders to transform complex sales workflows into autonomous processes.

Use AI coding assistants effectively and experiment with AI-augmented development workflows.

What We’re Looking For

7+ years of strong backend engineering experience.

[REQUIRED] Advanced Python expertise (including async programming, type hints, architecture patterns, and testing), with a minimum of 1 year of recent professional experience

[REQUIRED] Experience developing APIs in Python (e.g., Flask, Django, or FastAPI)

Experience designing scalable distributed systems.

You design thoughtful, well-architected systems and write clean, high-quality code, with a focus on performance and long-term maintainability.

Experience with GCP (preferred) or AWS.

Mindset: You’re energized by building systems that can reason and take action—not just generate responses.

You actively leverage AI coding assistants and are driven to push the boundaries of AI-augmented engineering.

You thrive in fast-paced startup environments where ownership is real and impact is immediate.

Strong communication skills are essential—you’ll collaborate closely with Product, Design, and Business stakeholders, and stay deeply connected to our users and the problems they’re trying to solve.

Fluency in English is required; Spanish is a plus.

Tech Stack

Backend: Python, FastAPI, Celery, PostgreSQL, uv (package-manager)

Frontend: NextJS, Tailwind

DevOps: Google Cloud, Kubernetes