Full-Stack Software Engineer Senior I

Job Title: Full-Stack Software Engineer Senior I

Reports to: Engineering Manager

Direct Reports: 0

Location: Remote - UK based only

End Date: 9/6/25

A role with Kooth is an exciting chance to join a fast growing business with a social purpose. Our mission is to provide welcoming and effective digital mental health support across the UK.

Kooth is a fast-growing business with a social purpose. Listed on the London Stock Exchange (LSE:KOO), our mission is to provide welcoming and effective digital mental health support.

Working in partnership with the NHS, we are already the UK's largest digital mental health platform for young people aged 10-25. We use the collective insight from over one million hours of professional support we have provided to guide people to self-help, community support, and professional help that matches their wants, needs, and goals in life.

Role Objective

Senior Engineers are trusted and impactful contributors who help set technical direction and drive execution for their squad and the wider department. They demonstrate ownership across their squad's work and regularly support others. Their contributions significantly influence Kooth's product and business objectives.

As a Senior Engineer, you'll help shape how we build reliable, scalable systems that guide young people to the right help. This is a hands-on role with real-world impact—helping create digital products that are meaningful, empathetic, and technically sound.

What You'll Be Doing

• Designing and building RESTful Node APIs, React frontends, and/or React Native mobile apps—contributing to system design and architectural evolution
• Leading by example in trunk-based development, automated testing, CI/CD, and infrastructure-as-code principles
• Taking ownership of performance, resilience, observability, maintainability, security, and accessibility
• Building and operating a suite of Node.js backend services, React-based web apps, and React Native mobile experiences that form the backbone of our mental health platform
• Taking end-to-end ownership of features, from idea through to production, with a strong sense of accountability and user impact
• Improving the systems you work on by applying thoughtful, pragmatic solutions to technical challenges
• Actively collaborating across disciplines and mentoring colleagues through pairing, code reviews, and knowledge-sharing
• Driving a shared understanding of user needs, commercial priorities, and how technical decisions influence business outcomes
• Contributing to and occasionally leading technical discussions and decisions
• Staying current with industry best practices in engineering, CI/CD, and architecture
• Supporting onboarding and professional growth of junior engineers and new hires
• Participating in the out-of-hours on-call rota and improving system reliability and incident response processes
• Continuously improving the systems you work on, applying a thoughtful and pragmatic approach to technical tradeoffs

Requirements

Essential

• 3+ years of hands-on experience in full-stack software development in a product-oriented environment
• Proficient in TypeScript, Node.js, and either React or React Native (or able to ramp up quickly with a solid engineering foundation), as well as database technologies such as PostgreSQL and experience in delivering a web or native mobile application
• Deep enthusiasm for full-stack software engineering with strong problem-solving capabilities
• Solid understanding of modern system architecture and the ability to contribute to its evolution
• Commitment to quality, with experience shipping maintainable, scalable, and well-tested code
• Ownership mentality with a focus on pragmatic delivery and continuous improvement
• Skilled in agile practices, data-informed decision-making, and building reliability.
• Excellent communication and collaboration skills, including mentoring and inspiring peers
• A team player who values collective success and nurtures a positive, inclusive engineering culture
• A proactive approach to solving technical challenges and influencing engineering direction
• Focus on pragmatic delivery, able to take ownership appropriately
• Strong communication skills, builds great colleague relationships across disciplines

Desired

• Deep experience with React or React Native in production environments
• Experience operating production systems and improving them through observability, testing, and thoughtful design
• A track record of delivering product improvements that tie into measurable business and user outcomes
• Familiarity with cross-platform design, mobile/web accessibility, and monorepos
• Expertise in trunk-based development, test automation and infrastructure as code
• Experience with scalable system design and architecture patterns
• Exposure to cloud-native technologies, particularly GCP or AWS with Kubernetes
• Leadership in cross-functional initiatives or technical working groups

Benefits

Are you looking for a fulfilling career with attractive perks and a supportive work environment? Look no further! We're excited to offer an incredible opportunity with a range of benefits that cater to your professional growth, well-being, and work-life balance.

• Competitive Salary:

Up to £75,000 dependant on experience

• Generous Annual Leave:

Enjoy 28 days of annual leave, in addition to public holidays, providing you ample time to recharge and spend quality moments with your loved ones.

• Professional Development:

Benefit from our yearly professional training programmes, tailored to your career aspirations and designed to enhance your skills and knowledge.

• Financial Security:

Secure your financial future with our pension contributions and annual company share option awards, giving you a stake in the success of the company.

• Health and Well-being:

Prioritize your health and well-being with our comprehensive Health Shield cover and access to an Employee Assistance Programme (EAP). The EAP offers 24/7 telephone mental health support and access to GP consultations, ensuring your mental and physical health are taken care of.

• Life Assurance:

Gain peace of mind knowing that you're covered with life assurance, providing up to four times your annual salary to your loved ones in the unfortunate event of your passing.

• Flexible Working:

Embrace the flexibility of remote working, allowing you to create a work-life balance that suits your needs and maximizes your productivity.

• Lifestyle Benefits:

If you're seeking a stimulating career where your well-being, growth, and contributions are valued, we invite you to apply and become a part of our dynamic and supportive team. Join us as we strive for success together!

_At Kooth, we are committed to fostering an inclusive and diverse workplace that values and embraces the unique contributions of every individual. We believe in equal opportunities for all, regardless of race, color, religion, gender, gender identity or expression or sexual orientation.

__Our dedication to creating a fair and unbiased environment is reflected in all aspects of our recruitment, hiring, and employment practices. We strive to provide a work environment that is free from discrimination, where every employee is treated with respect and dignity.

__Request for Reasonable Adjustments:

__We are dedicated to providing reasonable adjustments to applicants and employees with disabilities or individuals who require accommodations to participate in the application process, interviews, or job-related tasks. If you require any reasonable adjustments to ensure your equal participation in our recruitment process, please inform our Human Resources team.

__Your openness will allow us to work together to provide appropriate accommodations and ensure a fair and accessible application and employment experience for everyone.

_Kooth plc is committed to our responsibilities for safeguarding and promoting the welfare of children, young people and vulnerable adults . We are committed to recruiting candidates who share this commitment to safeguarding, and therefore we apply robust recruitment and selection procedures to ensure that the people selected are right for the job, and that all candidates are appropriately screened prior to appointment. This will include a DBS check.