Staff Software Engineer (JS)

🔒 Confidential Employer
Posted 12 August 2025
LOCATION
Leeds
TYPE
Full-time
LEVEL
Mid-Senior level
CATEGORY
Technology
This employer holds a UK Home Office sponsor license — sponsorship for this specific role is at the employer’s discretion

SKILLS

JavaScript/TypeScript SQL API Design Agile Development Microservices Testing frameworks RESTful APIs

FULL DESCRIPTION

Summary

We are seeking a versatile and skilled Staff Software Engineer (JS) responsible for the development and implementation of our platform and application services. The role requires a strong grasp of JavaScript/TypeScript, Service Design, Design Patterns and a solid understanding of the wider technical stack. A strong background in agile development, code reviews and rapid software iterations is essential.

Key Responsibilities

  • Design and develop software solutions
  • Implement features and enhancements
  • Ensure security by design
  • Optimise for performance and scalability
  • Develop APIs and microservices

Core Requirements/Qualifications/Skills

  • Extensive knowledge of JavaScript/TypeScript
  • Experience with SQL, including schema design and optimisation
  • Experience with API (RESTful/Sockets/GraphQL), microservice architecture and development.
  • Strong background in agile development methodologies.

Key Responsibilities

  • Design and develop software solutions: Write clean, maintainable, and efficient code for our platform and applications. This includes developing new features, fixing bugs, and optimising existing code.
  • Implement features and enhancements: Collaborate with product managers and other developers to implement new features and improve existing ones. Participate in design discussions and provide input on technical feasibility and best practices.
  • Ensure security by design: Integrate security best practices into the development process to ensure that software is secure from the ground up. Conduct regular code reviews and security assessments to identify and mitigate potential vulnerabilities.
  • Optimise for performance and scalability: Design and implement solutions that can dynamically scale to meet varying demands and ensure high performance and availability. Use profiling tools to identify performance bottlenecks and optimise code accordingly.
  • Develop APIs and microservices: Design and implement APIs and microservices to support the platform’s functionality. Ensure that APIs are secure, scalable, and well-documented.

Quality Assurance:

  • Develop and execute test plans: Create comprehensive test plans and test cases to ensure that software meets quality standards. This includes functional, regression, performance, and security testing.
  • Automate testing processes:Use to automate functional, regression, and performance testing. Ensure that automated tests are integrated into the CI/CD pipeline and run regularly.
  • Conduct code reviews: Review code written by other developers to ensure it meets quality and security standards. Provide constructive feedback and suggest improvements.
  • Identify and resolve defects: Work closely with developers to identify, document, and resolve software defects. Use bug tracking tools tomanage and prioritise issues.

Agile Development:

  • Participate in agile ceremonies: Engage in sprint planning, daily stand- ups, and retrospectives to ensure effective and efficient development cycles. Collaborate with team members to refine requirements, estimate tasks, and plan sprints.
  • Collaborate with cross-functional teams: Work closely with product managers, and other developers to deliver high-quality software solutions. Foster a culture of collaboration and knowledge sharing within the team.
  • Continuously improve processes: Identify and implement improvements to development and testing processes to increase efficiency and quality. Stay up-to-date with industry best practices and emerging technologies.

Qualifications

Education:

Bachelor’s or Master’s degree in Computer Science or a related field.

Experience:

  • Proven experience as a senior Software Developer in a tech start-up or fast-paced environment.
  • WebGL/three.js experience is highly desirable
  • Strong background in agile development methodologies.
  • Experience with API (RESTful/Sockets/GraphQL), microservice architecture and development.
  • Experience with cloud-native platform patterns

Technical Skills:

  • Extensive knowledge of JavaScript/TypeScript
  • Experience with SQL, including schema design and optimisation
  • Experience with testing frameworks and tools
  • Familiarity with security tools and practices
  • Experience with designing RESTful APIs and microservices.
  • Experience with data scraping, modelling and security
  • MVP is currently built using the following technologies and development languages; .NET (9), C#, React, MySQL, Docker, and Python.

Soft Skills:

  • Excellent problem-solving and analytical skills.
  • Strong communication and collaboration abilities.
  • Ability to work in a fast-paced, dynamic environment and manage multiple priorities.
  • Attention to detail and a proactive approach to identifying and addressing issues.
  • Experience working on mission-critical or SaaS services is desirable

Apply for this role

If you are interested in this position, please send your CV and a short cover letter to [contact hidden].

We look forward to hearing from you!

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