Senior Backend Software Engineer - Python

Aircall; Madrid; Presencial; EUR 90.000 - 120.000; Jornada completa

Ventajas ofrecidas por este puesto de trabajo

Competitive salary package

Benefits

Descripción de la vacante

Aircall is a unicorn AI-powered customer communications platform. We seek a Senior Python Engineer to design production-grade Python services, build scalable distributed systems, and integrate AI-driven components to automate sales workflows.

You’ll collaborate with AI engineers, product, and leaders to push fast, thoughtful decisions in a startup environment while delivering high-impact solutions that scale globally.

Formación

• 7+ years backend engineering experience.
• Advanced Python (async, typing, architecture, testing).
• Experience designing scalable distributed systems.
• Thoughtful, well-architected systems with performance focus.
• Experience with GCP or AWS.
• Driven to push AI-augmented engineering boundaries.
• Strong collaboration with Product, Design and Business teams.
• English fluency; Spanish is a plus.

Responsabilidades

• Design and implement production-grade Python services with clean architecture.
• Architect scalable, distributed systems using DDD principles.
• Integrate with external SaaS systems (CRMs, dialers, OAuth).
• 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 and workflows.
• Work closely with AI engineers, product and founders to automate complex sales workflows.
• Use AI coding assistants and experiment with AI-augmented development workflows.

Conocimientos

Advanced Python

Distributed systems design

Backend engineering

English fluency

Spanish a plus

Strong communication

Herramientas

Python

FastAPI

PostgreSQL

Celery

Google Cloud

Kubernetes

NextJS

Tailwind

Descripción del empleo

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. We’re 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. Aircall’s 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. We’ve built a product customers love and a business that’s scaling quickly, backed by world-class investors and driven by rapid AI innovation across multiple product lines.

At Aircall, you’ll join a company in motion. We’re ambitious, product-driven, and execution-focused, with visible impact, fast decisions, and real growth.

How we work at Aircall

We’re 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, you’ll feel at home here.

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.

Key Responsibilities

• 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.

Qualifications

• 7+ years of strong backend engineering experience.


• Advanced Python expertise (async, typing, architecture patterns, testing)


• 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

Why join us?

• Key moment to join Aircall in terms of growth and opportunities


• Our people matter, work-life balance is important at Aircall


• Fast-learning environment, entrepreneurial and strong team spirit


• 45+ Nationalities: cosmopolite & multi-cultural mindset


• Competitive salary package & benefits

DE&I Statement

At Aircall, we believe diversity, equity and inclusion – irrespective of origins, identity, background and orientations – are core to our journey.

We pride ourselves on promoting active inclusion within our business to foster a strong sense of belonging for all.

We’re working to create a place filled with diverse people who can enrich and learn from one another.

We’re committed to ensuring that everyone not only has a seat at the table but is valued and respected at it by providing equal opportunities to develop and thrive.

We will constantly challenge ourselves to make sure that we live up to our ambitions around diversity, equity and inclusion, and keep this conversation open.

Above all else, we understand and acknowledge that we have work to do and much to learn.

Want to know more about candidate privacy? Find our Candidate Privacy Notice here.

We may use artificial intelligence (AI) tools to support parts of the hiring process, such as reviewing applications, analyzing resumes, or assessing responses. These tools assist our recruitment team but do not replace human judgment. Final hiring decisions are ultimately made by humans. If you would like more information about how your data is processed, please contact us.