Javascript jobs in United Kingdom

Job Title: Software Developer

Location: Hybrid, (2/3 Days in the office in Poole, Dorset)

Reporting to: Product Manager

Salary: Up to £50,000 + Performance Bonus/Excellent Benefits

Holt Engineering are working with a company who develops a cutting-edge Football technology, combining hardware and software systems to create elite performance training equipment. Their systems are used globally to improve athlete performance through real-time feedback, analytics, and immersive training experiences.

We are seeking a capable and adaptable Software Developer to design, build and maintain the software platforms that power advanced hardware-led training and performance systems. This role spans the full technology stack, from embedded microcontrollers through Linux-based machine control and cloud-connected web applications. You will take ownership of core software components, contribute to architectural decisions, and work closely with cross-functional teams to deliver reliable, secure and scalable systems used internationally. The role suits a developer who enjoys working close to hardware, solving real-world problems, and seeing their code deployed into live operational environments.

• System & Network Architecture
  • Design, implement and evolve software architectures integrating embedded devices, servers and cloud platforms
  • Configure and manage secure, resilient networks supporting distributed systems
  • Manage VPN connectivity for deployed machines, including access control and key management
  • Maintain Linux (CentOS) servers for live and test environments, including monitoring, backups and incident response
• Software Development
  • Embedded systems: Develop and maintain real-time C++ applications on microcontrollers (Arduino, Atmel Studio)
  • Linux applications: Build near real-time control and interface applications on Raspberry Pi using Qt and Linux
  • Web platforms: Develop real-time user interfaces, APIs and dashboards using JavaScript, PHP, HTML, CSS, JSON and XML
  • Extend and maintain a proprietary scripting language to support new operational modes while preserving backward compatibility
  • Design, optimise and maintain MariaDB/MySQL databases and data-access layers
  • Apply disciplined version control and collaboration using Git/Bitbucket
  • Define and execute test strategies across embedded, server and web layers
  • Review and integrate third-party code and deliverables to agreed quality standards
• Support & Operational Delivery
  • Support system commissioning and configuration during manufacturing and deployment
  • Provide second-line technical support for live systems, diagnosing and resolving complex issues
  • Assist with maintenance, upgrades and system returns
  • Produce clear, structured technical documentation including specifications, APIs and installation guides
• Innovation & Continuous Improvement
  • Contribute to R&D initiatives, prototyping new features and system capabilities
  • Evaluate emerging technologies to enhance performance, security and scalability
  • Provide technical input to influence product direction and development priorities

• Strong commercial experience developing in C++ within Linux-based environments
• Hands-on experience with embedded systems (Arduino, Atmel Studio, Raspberry Pi, Qt)
• Proficiency in web technologies: JavaScript, PHP, HTML, CSS, JSON, XML
• Solid experience with MariaDB/MySQL databases and API design
• Proven ability to configure and maintain Linux servers, VPNs and secure networks
• Experience using Git/Bitbucket in structured development workflows
• Strong analytical, documentation and communication skills
• Ability to work autonomously, manage priorities and deliver in a fast-moving environment

• Background in sports technology, IoT, industrial systems or consumer electronics
• Knowledge of secure coding principles and cybersecurity best practices
• Exposure to CI/CD pipelines, Docker or DevOps tooling
• Familiarity with Agile delivery and tools such as JIRA
• Experience supporting junior developers or coordinating external contractors
• Python as a Programming Language

Occasional UK and international travel may be required to support installations, collaborate with partners or assist with system deployments.

This role offers the opportunity to work on technically rich, real-world systems where your work directly impacts end users. You’ll have visibility across the full product lifecycle and the autonomy to influence how systems are designed, built and scaled.

• A collaborative engineering environment with genuine technical ownership.
• Exposure to embedded, web and cloud technologies in a single role.
• Opportunities to contribute to product innovation and R&D.
• Support for professional development as the organisation grows.