Senior Software Engineer

Holt Executive; City Of London; Hybrid; GBP 90,000 - 120,000; Full time

Benefits offered by this job

Hybrid working arrangements

Competitive salary and benefits

Pension scheme and private healthcare

Professional development and training

Job summary

Holt Executive is seeking a Senior Software Engineer to design, develop, and maintain software for real-time data platforms and operational tooling. You will work across engineering, product, and operations to deliver reliable, scalable solutions.

The role emphasizes hands-on development in Java and Node.js, with exposure to distributed systems, monitoring, and service assurance. A hybrid working arrangement and competitive benefits are offered.

Qualifications

• Degree in Computer Science, Software Engineering, or equivalent.
• Hands-on Java development in real-time operational environments.
• Strong JavaScript and Node.js experience.
• Experience across Windows and Linux.
• Good knowledge of IP networks and troubleshooting with Wireshark.
• Experience with event streaming (Kafka).
• Understanding of SDLC and clean code practices.
• Ability to document technical work clearly for engineering teams.
• Proven collaboration across cross-functional teams.
• Awareness of security best practices in software.

Responsibilities

• Develop and support software applications used in operational environments.
• Design and implement new features from user and business requirements.
• Collaborate with engineers to understand system architectures and monitoring needs.
• Analyze performance, troubleshoot, and assist operations with fault diagnosis.
• Contribute to design reviews, testing, and documentation.
• Work with stakeholders and suppliers to deliver effective solutions.
• Support ongoing maintenance and improvement of systems.
• Identify opportunities to improve tooling and reliability.
• Contribute to full SDLC from requirements to deployment.
• Provide on-call support for live operational systems.

Skills

Java

JavaScript

Node.js

IP networking

Wireshark

Kafka

OOP principles

Code reviews

Documentation

Team collaboration

Education

Bachelor's degree in Computer Science

Tools

Windows

Linux

Git

Job description

A leading technology organisation is seeking an experienced Senior Software Engineer to join a team responsible for developing and supporting critical software applications used to monitor, analyse, and optimise large-scale operational systems.

This is an exciting opportunity for a hands-on engineer to work on real-time data platforms, operational tooling, and service assurance solutions that provide valuable insights into complex network environments. You will play a key role in designing, developing, and maintaining software that supports business‑critical operations, working closely with engineering teams, product stakeholders, and operational users.

The role combines software development, system integration, troubleshooting, and continuous improvement, making it ideal for someone who enjoys solving complex technical challenges and delivering reliable, scalable solutions.

Key Responsibilities

• Develop, enhance, and support software applications used within operational environments.
• Design and implement new features based on user and business requirements.
• Work closely with engineering teams to understand system architectures and ensure effective monitoring and data collection capabilities.
• Analyse system performance, troubleshoot issues, and support operational teams with fault diagnosis.
• Participate in software design, code reviews, testing, and documentation activities.
• Collaborate with internal stakeholders, product teams, and third-party suppliers to deliver effective solutions.
• Support the ongoing maintenance and improvement of operational systems.
• Identify opportunities to improve processes, tooling, and software reliability.
• Contribute to the full software development lifecycle, from requirements gathering through to deployment and support.
• Provide technical support for live operational systems, including occasional on-call responsibilities.

Experience Required

• Degree in Computer Science, Software Engineering, or a related technical discipline.
• Strong hands-on experience developing software using Java within a real-time operational environment.
• Strong experience with JavaScript and Node.js development.
• Experience working with both Windows and Linux operating systems.
• Good understanding of IP networking and experience troubleshooting network issues using tools such as Wireshark or similar.
• Experience working with event streaming technologies such as Kafka.
• Strong understanding of the full software development lifecycle.
• Experience producing high-quality, maintainable, and reusable software within a collaborative engineering environment.
• Understanding of object-oriented analysis, design principles, and common design patterns.
• Strong communication skills with the ability to collaborate effectively across technical and non-technical teams.
• Awareness of software and network security best practices.
• Experience producing clear technical documentation to support ongoing development and operational support.

Desirable Experience

• Real-time monitoring or service assurance platforms.
• Large-scale distributed systems.
• Data analysis and operational dashboards.
• Network management or telecommunications environments.
• Supporting production systems within a 24/7 operational environment.

The Ideal Candidate

You will be a proactive and curious engineer who enjoys understanding complex systems, identifying improvements, and developing practical solutions. You will have strong technical ownership, excellent problem-solving skills, and the ability to work collaboratively across engineering and operational teams.

This is an opportunity to contribute to highly visible software platforms that support critical services while working within a technically challenging and collaborative engineering environment.

Benefits

• Hybrid and flexible working arrangements.
• Competitive salary and comprehensive benefits package including annual bonus.
• Pension scheme and private healthcare.
• Professional development and training opportunities.
• Opportunity to work on cutting-edge satellite technologies.
• Collaborative engineering culture with exposure to complex international programmes.