Principal Software Engineer (Backend) – 10+ Years Experience

About the role

As a Principal Engineer you will design and deliver end‑to‑end features for CirclesX, the telco operating system that powers millions of customers worldwide. You will work closely with product and solution‑architecture teams in a Scaled Agile environment, providing hands‑on technical leadership and ensuring the platform scales across multiple markets.

Key responsibilities

• Gain deep domain knowledge of bounded contexts, customer and operator experiences within the CirclesX platform.
• Design and implement solutions that follow platform, DDD and architectural standards.
• Provide technical leadership, mentor staff, senior and junior engineers, and promote best practices.
• Translate high‑level business requirements into detailed, backward‑compatible designs.
• Incorporate performance, reliability and scalability best practices into all implementations.
• Collaborate with security and compliance teams to meet policies and regulations.
• Implement monitoring and observability strategies for production readiness.
• Maintain up‑to‑date documentation of designs, APIs and domain knowledge.
• Own end‑to‑end delivery of assigned features within each Program Increment.

Required profile

• 12+ years of industry experience with a degree in Computer Science or equivalent; MSc is a plus.
• Proven ability to lead a team of 6‑10 engineers and communicate effectively.
• Strong hands‑on coding skills and deep expertise in at least one modern backend framework (Java/Spring Boot or Golang).
• Experience with modern front‑end frameworks, especially ReactJS.
• Solid knowledge of SQL and NoSQL databases (MongoDB, MySQL, PostgreSQL, Redis) and data‑model optimisation.
• Understanding of software design patterns, enterprise integration patterns, MSA, DevOps, observability and Domain‑Driven Design.
• Experience with containerisation and Kubernetes, with preferred exposure to Elasticsearch/Kibana and messaging systems like RabbitMQ.

Required skills

• Java
• Spring Boot
• Golang
• ReactJS
• Vanilla JS, CSS, jQuery
• MongoDB
• MySQL
• PostgreSQL
• Redis
• Elasticsearch
• Kibana
• RabbitMQ
• Kubernetes
• Docker
• Domain‑Driven Design
• Micro‑services Architecture
• DevOps
• Observability tools