Senior Developer

Cerillion Technologies Ltd; Greater London; On-site; GBP 65,000 - 85,000; Full time

Job summary

A leading software company in Greater London is looking for a Senior Developer to join its Software Engineering team. The role involves technical design, development of BSS/OSS products, and mentoring junior developers. The ideal candidate will have extensive experience in Java technologies and a strong grasp of Agile methodologies. This opportunity allows you to tackle complex business challenges and work with cutting-edge technology in a collaborative environment.

Qualifications

• Extensive experience in software design and development using Java-based technologies.
• Experience in technical leadership or senior developer roles.
• Hands-on experience with RESTful APIs and Microservices.

Responsibilities

• Design and develop customisations to core BSS products.
• Perform code reviews and ensure compliance with development standards.
• Provide build and release instructions to DevOps and QA teams.

Skills

Java

Spring Boot

RESTful APIs

Microservices

Kubernetes

SQL

Angular

Git

Education

Degree in Computer Science or Software Engineering

Tools

Maven

Jenkins

Job description

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Job Description

We are looking for a Senior Developer to join our Software Engineering team in London. This
role is ideal for a hands-on technologist who enjoys tackling complex business challenges and
delivering high-quality software solutions. The successful candidate will be responsible for
technical design, development, and delivery of enhancements to Cerillion's core BSS/OSS
products.

You will work closely with project managers, architects, and cross-functional development
teams to ensure the delivery of robust, scalable, and maintainable systems. As part of this role,
you will also mentor junior developers and contribute to code quality and process improvement
initiatives.

Key Responsibilities

Before Development

• Understand customer business and R&D requirements.
• Analyse existing system functionality and design gaps.
• Participate in requirements and design discussions with architects and analysts.

Development & Testing

• Design and develop customisations to Cerillion's core BSS products, including CRM, Mediation, Charging and Rating, Billing, Bill Printing, Credit Control, Provisioning, Product Catalogue, and Self Service.
• Develop new R&D; features and modules for inclusion in the product suite.
• Perform code reviews, unit testing, and ensure compliance with development standards.
• Work collaboratively in Agile environments and contribute to sprint planning and estimations.
• Support bug fixing, performance optimisation, and integration testing.

Release & Deployment

• Provide build and release instructions to DevOps and QA teams.
• Support build and deployment processes, ensuring smooth release cycles and quality assurance.

Reporting & Collaboration

• Report project/task status, risks, and issues to the Software Engineering Manager.
• Mentor developers and assist in technical troubleshooting and solutioning.
• Contribute to technical design documentation and best practice guidelines.

Requirements

Education & Qualifications

• Educated to degree level (or equivalent) in Computer Science, Software Engineering, or a related discipline.

Experience

• Extensive experience in software design and development using Java-based technologies.
• Experience in technical leadership or senior developer roles.
• Experience working on high-transaction, large-scale systems in telecoms, billing, or similar enterprise domains preferred.

Technical Skills

Essential

• Strong expertise in Java, Spring Boot, and J2EE.
• Hands-on experience with RESTful APIs, Microservices, and Containerisation (Kubernetes/OpenShift).
• Solid understanding of RDBMS, SQL, and PL/SQL.
• Experience with Angular, JavaScript, Bootstrap, HTML5, and CSS3.
• Familiarity with application servers such as JBoss or Oracle 10gAS.
• Proficiency in Git-based source control, debugging, and build tools (e.g., Maven, Jenkins).
• Knowledge of software development lifecycle (SDLC) and Agile methodologies.

Desirable

• Exposure to JBoss Fuse/Apache Camel, DROOLS (JBoss Rules), or Business Intelligence platforms.
• Experience with C/Pro*C on UNIX environments.
• Knowledge of Telecom BSS/OSS, Mediation, Billing, or Online Charging systems.
• Understanding of Cloud-native architectures and DevOps pipelines.

Behavioural Competencies

Essential

• Quick learner with excellent analytical and troubleshooting skills.
• Strong verbal, written, and documentation communication abilities.
• Team player with collaborative spirit and mentoring capability.
• Highly self-motivated, quality-focused, and proactive in problem-solving.
• Organised, disciplined, and able to manage multiple priorities effectively.

Desirable

• Demonstrates leadership and initiative in driving innovation and process improvement.
• Skilled in estimation, planning, and agile delivery practices.

Additional Information

This is an excellent opportunity for a passionate developer who enjoys working with
leading-edge technologies in a dynamic, collaborative environment. You'll be part of a global
team developing solutions that are transforming telecoms, cable, and finance industries.
International travel may be required occasionally.