Intern Software Engineer

At Zaleos, we build software for real-time communication (RTC) systems. We design, develop, test, and maintain software for companies that rely on protocols such as SIP, RTP, and WebRTC. Our mission is clear:
to help organizations ensure secure, stable, and always-available communications.

We work in mission-critical environments where reliability is not optional:

• Voice AI: we enhance the telephony layer for conversational agents and intelligent voice platforms.

• Enterprise Communications: we develop software for VoIP, CPaaS, and cloud PBX platforms.

• Emergency Systems: extensive experience designing and building Core Services for emergency call networks in the U.S.

Since 2015, we have been helping companies across different industries keep their RTC communications running at all times, with a culture focused on engineering excellence, quality, and technical responsibility.

At Zaleos, we share a culture built on trust, autonomy, and technical excellence. Every team member acts with responsibility and professional judgment, contributing solutions while safeguarding product quality.

Our values:

• Total Integrity
  Transparency, accountability, and trust — even when things don’t go as planned.

• Ownership
  Everyone works with autonomy and a strong sense of ownership over their work.

• Excellence
  We deliver clean, stable, and maintainable systems we can truly be proud of.

At Zaleos, we take engineering seriously. Our culture blends Agile, Lean, and DevOps principles, with a strong focus on technical resilience, architectural clarity, and continuous improvement.

Our technical principles — The Tao of Zaleos — guide everything we do:

• Resiliency – Always up, always ready.
  We design for fault tolerance and continuous availability.

• Strategic Modularity – Low coupling, high cohesion.
  We build clear, cohesive modules with minimal dependencies.

• Immutability – Certainty through consistency.
  Everything we deploy is automated and controlled — no improvisation.

• Everything as Code – What is not version-tracked is lost.
  All critical assets are under version control.

• Pragmatism – Effective solutions over perfect ideals.
  We prioritize useful solutions over theoretically perfect ones.

• Development of software competencies in the telecommunications field: SIP / IMS protocols.
• Software development following high-quality standards. Development of systems and DevOps skills (Linux, Docker, CI).
• Use of Open Source tools and libraries in a GNU/Linux environment.
• Participation in team dynamics: meetings, presentations, pair programming, and agile methodologies.
• Learning and contributing in a high-level technical environment focused on software quality and process efficiency.
• Above all, you will have the opportunity to learn in a real-world environment, participating in impactful projects and working closely with experienced professionals.

• Students pursuing a degree in Computer Science, Telecommunications Engineering, or related fields.
• Availability to sign an internship agreement with the educational institution.
• English level: B2.
• Knowledge of Unix/Linux or GoLang is a plus.
• Above all, a strong willingness to learn and contribute.

• Hybrid model: on-site Tuesday, Wednesday, and Thursday at our offices in Pozuelo de Alarcón (Madrid), and remote work on Monday and Friday.
• Duration: 3 months (with the possibility of extension).
• Financial support for your studies, proportional to your level of dedication, because we value your time and commitment.
• Strong growth opportunities in a real, dynamic learning environment, with the chance to participate in meaningful projects.
• Mentoring and continuous support from the team.

Because here, engineering has a purpose. Every project impacts our clients’ real-time communications and helps keep critical communication systems running worldwide.

If you’re passionate about technology, motivated by technical challenges, and value quality over quantity, this is the place for you.