Senior Software Engineer – Bucharest Romania

Role objective and key accountabilities:The Senior Software Engineer is responsible for designing, developing, and maintaining robust and scalable backend systems that support Vox Solutions’ telecom firewall products and services. This role involves architecture high-performance, reliable, and secure backend solutions that enable the seamless delivery of messaging, signaling, and data services. Working closely with cross-functional teams, the Senior Software Engineer contributes to ongoing improvements in platform performance, security, and scalability to ensure Vox Solutions’ offerings remain competitive and aligned with evolving customer and operator needs.

Reports to: Engineering team lead

Key interactions: Backend and frontend developers, DevOps/Infrastructure, Analytics team, QA/Testing, Product Management

Key Responsibilities:

• Develop, test, and implement scalable, distributed, and fault-tolerant backend services and APIs. Design and maintain integrations with telecom protocols (SS7, CAMEL, Diameter, 2G–5G, SIP and SMPP) and contribute to the development of telecom firewall capabilities.
• Build and manage containerized services using Docker and Kubernetes, ensuring efficient deployments and high availability.
• Work closely with cross-functional teams—including DevOps, frontend, analytics, and QA—to deliver integrated, observable, and scalable backend solutions.
• Participate in the design and planning of new telecom-oriented applications and features.
• Participate in the design and implementation of machine learning–driven features (e.g., traffic classification, anomaly detection, vectorisation pipelines).
• Support existing software with troubleshooting and issue resolution, especially in carrier-grade, high-availability environments.
• Ensure code is documented, maintainable, and standardized across the team.
• Ensure development is aligned with best practices, industry standards, and telecom security requirements.
• Plan and estimate tasks required for development, working within agile methodologies.
• Contribute to system performance improvements, including real-time event streaming (Kafka) and distributed processing pipelines.
• Provide technical guidance and mentorship to junior engineers and interns.

Skills:

• Bachelor’s or Master’s degree in Computer Science, Telecommunications, Electronic Engineering, IT, or a related discipline.
• Committed to the delivery on time and quality of the results.
• Creative and problem solver with the ability to present multiple solutions and potential side effects.
• Ability to work in a team, very good communication skills, and attention to detail.
• Understanding corporate business processes and improving technical and personal skills following the directions given by direct managers.
• Ability to mentor and guide junior engineers and interns, fostering skill growth and knowledge transfer.
• Strong organizational skills with the ability to coordinate tasks and support the Engineering Team Lead in managing priorities.
• Experience contributing

Experience:

• Expertise in telecom signaling protocols: SS7, CAMEL, Diameter, SIP; and experience with SMPP for messaging integration (required).
• Experience with SMS firewalling, routing, or telecom network infrastructure.
• Hands-on experience with Docker and Kubernetes for building and running containerized, cloud-native applications.
• Knowledge of ML concepts (classification models, vectorisation, anomaly detection).
• Knowledge of distributed event streaming platforms (Kafka).
• Minimum 3 years’ experience in a similar position (5+ years overall backend experience preferred).
• Expertise in backend development using Java (Spring Boot) on Linux.
• Experience building APIs and RESTful services.
• Strong knowledge of relational databases (MariaDB, MySQL) and NoSQL (MongoDB).
• Experience with in-memory databases (Redis).
• Experience with agile software development and collaboration tools (Confluence, Jira).
• Familiarity with MVC and microservices architectures.
• Proficiency with version control systems (Git).
• Experience with software automation tools (Ansible).
• Experience with the Python programming language.
• Excellent English speaking and writing skills.

About VOX

VOX is a visionary company led by a single founder, currently leading the way in flashcall and telecom carrier services, transforming the way businesses communicate, authenticate and connect. As a hyper-growth company, VOX achieved over 25% YoY revenue growth last year and is aiming to reach $100M+ revenue this year. VOX is looking for a team of growth-driven individuals to take the company to new heights.

VOX’s cutting-edge technology and dedicated customer service team ensure that telcos and enterprises maintain secure, fast, and reliable connections while protecting their networks. VOX’s promise of a hassle-free experience and superior customer support enables telcos and enterprises to focus on success. As a company, VOX focuses on solutions that monetize the assets of mobile network operators.

Joining VOX offers the opportunity to work with the industry’s leading technologies and help them stay ahead and continue to innovate with a comprehensive suite of flashcall and telecom carrier services. VOX is highly committed to providing its employees with a dynamic, forward-thinking work environment, competitive compensation and benefits, vacation and time-off packages, and stock options. This is a once-in-a-lifetime opportunity for highly ambitious individuals, as VOX plans to expand its solutions

Join the team and help shape the future of the telecom industry!