Senior Backend Software Engineer, Voice Squad

Diabolocom UK Ltd; Paris; On-site; EUR 90,000 - 120,000; Full time

Benefits offered by this job

Remote work options

Team-building events

High-quality IT equipment

Career growth opportunities

Job summary

Diabolocom is seeking a Senior Backend Software Engineer to join the Voice Squad in Paris. You will design and implement backend services for core telephony features, focusing on reliable, scalable distributed systems and close collaboration with product and engineering teams.

The ideal candidate has 7+ years in software development, 3+ years with Java/Kotlin, and strong experience with PostgreSQL; autonomy and leadership potential are highly valued.

Qualifications

• 7+ years in software development within product-focused environments.
• 3+ years with Java/Kotlin.
• Experience with PostgreSQL.
• Ability to design distributed systems and make architectural decisions.
• Autonomy with leadership potential.

Responsibilities

• Design and implement backend services for Voice Squad.
• Develop robust distributed systems focusing on reliability and scalability.
• Collaborate with cross-functional teams across product and engineering.
• Improve existing codebase and performance.
• Own architectural decisions influencing platform in production.

Skills

Java/Kotlin

Distributed systems design

Architectural decisions

Relational databases PostgreSQL

Spring Boot

Leadership potential

Codebase improvements

Education

Bachelor's degree in Computer Science

Tools

Docker

RabbitMQ

Redis

Kubernetes

Job description

About Diabolocom

Diabolocom is a leading European provider of AI-first, cloud-based contact centre (CCaaS) and customer experience (CX) solutions that help companies deliver seamless, personalised customer experiences at scale. The platform combines proprietary, purpose-built AI technology for customer service, native telecom infrastructure, and deep CRM integrations to automate tasks, elevate data quality, and empower agents across all customer touchpoints.

Trusted by 400+ clients, with deployments across more than 60 countries in Europe, North America, South America, and the Middle East, Diabolocom combines the agility of SaaS innovation with carrier-grade voice performance. With eight offices worldwide and more than two decades of experience, the company is committed to advancing customer loyalty and growth through sovereign, intelligent, and scalable communication technology.

In the context of our exponential growth, we are strengthening our internal engineering team and opening a Senior Backend Software Engineer position in our Voice Squad.

About the Voice Squad

Voice Squad is the software core of our CCaaS telephony. It is responsible for the core technical services that ensure secure, high-performance processing of phone calls on the Diabolocom platform. It manages critical components related to call routing, media stream handling and other voice related services.

Voice provides information to all parts of the system to help our clients observe agents and their business in general.

What’s next for the Voice Squad?

In the coming year, we plan to:

• Introduce Telephony as a Service that will be part of Omni-channel as a Service.
• Perform massive optimization and refactoring to enable faster feature delivery.

Technical Stack:

• Languages: Java 25, Kotlin 1.9, Go
• Framework: Spring Boot 3.x.x
• Database: PostgreSQL
• Message Broker: RabbitMQ
• Caching: Redis
• Containerization: Docker

The team currently consists of:

• 3 QA engineers
• 5 backend developers
• 1 team lead

What We’re Looking For:

• 7+ years in software development within product-focused companies, with at least 3+ years working extensively with Java/Kotlin.
• Experience working with relational databases (PostgreSQL preferred).
• Experience with Spring Boot would be a plus.
• Experience in designing and implementing effective distributed systems. Ability to make architectural decisions and evaluate their impact on system performance, scalability, and reliability.
• Strong autonomy and leadership potential, with a willingness to grow into a lead role.
• Comfortable working with and improving an existing codebase.
• Strong engineering culture, attention to the details, business-centric mindset.

What We Offer:

• A collaborative and multicultural environment with a team that fosters professionalism, values innovation, and encourages knowledge-sharing.
• Work on cutting-edge distributed communication systems in a fast-growing company, with real opportunities to make an impact.
• Opportunities to take on new challenges and advance your career.
• High-quality IT equipment of your choice.
• Flexible work arrangements and remote work options.
• Regular team-building events.

Recruitment Process:

• Intro call with a Talent Acquisition Manager
• Live coding challenge
• Design interview through screen sharing with our Lead Software Engineer
• Final interview with Alexander, our Head of Software Engineering