Software engineer, Programmable Comms

Team: 10001 - Communications Platform

Location: Madrid Office

Commitment: Permanent Full Time Employee

Workplace Type: hybrid

The Team:

The Programmable Communications Team is responsible for all technology aspects related to the voice and messaging infrastructure of Aircall products. The team works to deliver high-quality and real-time communications to our users while operating in all areas at carrier-grade expectations (stability, maintainability, scaling, and uptime). Our shared ambition is to provide the best voice and messaging infrastructure for Aircall customers and help other Aircall engineering teams deliver as much value as possible on top of it.

Key Responsibilities:

• Design and build highly scalable and secure backend services, ensuring high availability, performance, and security to support high-volume workloads

• Design and maintain robust CI pipelines (GitLab CI), release workflows, and automated testing to implement continuous delivery best practices in production environments.

• Debug and optimize the application's performance, focusing on memory leaks and CPU usage in a desktop environment, critical for maintaining a high audio quality during calls.

• Operate, monitor, and optimize distributed systems in AWS production environments

• Lead initiatives to improve the reliability, resilience, and performance of our distributed systems, from design through production operation.

• Apply a deep understanding of RTC / VoIP architectures and protocols

• Participate in an on-call rotation to respond to critical system issues.

Qualifications:

• You have solid experience building backend services with a strong focus on security, scalability, availability, and performance.

• You have strong knowledge of CI/CD pipelines, infrastructure-as-code, automated testing, and deployment best practices.

• You have hands-on experience with GitLab CI/CD (or similar), release workflows, code reviews, and continuous delivery in production.

• You are proficient in working in containerized environments (Docker, Kubernetes).

• You have experience operating and optimising systems in AWS production environments, ideally supporting high-volume, high-availability workloads.

• You have the ability to troubleshoot, monitor, and improve distributed systems running in production.

• You have an understanding of RTC / VoIP architectures and protocols (SIP, RTP).

• You are familiar with open-source SIP/RTC technologies such as FreeSWITCH, Kamailio, Asterisk, or similar.

• You have exposure to media servers, signaling flows, or real-time communications debugging.

• You stay current with modern development practices and tooling, including AI-assisted development tools, to maximize your productivity

• You have strong communication skills and fluency in English (written and spoken).

• You are autonomous, proactive, and comfortable owning features end-to-end.

• You are pragmatic and have a willingness to experiment, iterate, and continuously improve systems.