Once For All is a high-growth, cloud-based, SaaS subscription business. Our technology helps our customers to manage their supply chain governance, risk management and compliance. We work across public and private sector and have over 250k customers across the UK across 20 different sectors including construction, transport, retail, hospitality education, facility and property management, manufacturing, local and central government.
Role Summary:
We are seeking an experienced and driven Senior Software Developer to join our technology team. This role involves taking technical ownership of projects, guiding team members through design and development, and contributing to the continuous improvement of our engineering practices. You will play a key role in delivering reliable, scalable, and maintainable software solutions while mentoring junior developers and promoting technical excellence across the team.
Job Responsibilities:
- Technical Direction : Provide technical direction and mentorship to junior and mid-level developers, conducting code reviews and supporting their professional growth.
- Feature Ownership: Take full responsibility for the delivery of features — from technical design and architecture through development, testing, deployment, and monitoring in production.
- Software Development: Design, build, and optimize high-quality software using modern engineering principles and practices.
- Automated Testing: Lead by example in writing and maintaining automated unit, integration, and end-to-end tests to ensure stability and reliability.
- SDLC & Scrum Practices: Actively contribute to and help facilitate the running of our Software Development Life Cycle (SDLC) and Scrum process, including workshops, sprint planning, backlog refinement, daily standups, sprint reviews, and retrospectives.
- Architecture & Design: Pro-actively engage in discussions and decisions around system architecture, scalability, and maintainability.
- Collaboration: Partner with product managers, designers, and stakeholders to define requirements, refine scope, and deliver impactful solutions.
- Code Quality & Best Practices: Enforce and improve development standards, ensuring code consistency, maintainability, and adherence to best practices.
- Continuous Improvement: Champion process and tooling improvements across the engineering organization.
- Documentation: Ensure technical and architectural documentation is complete, clear, and up-to-date.
Required skills and qualifications:
Experience: Minimum 5+ years of professional software development experience, with proven ability to deliver complex applications in production environments.
Back end skills:
- Strong proficiency in C#, Python, and/or Java.
- Deep experience building and maintaining APIs and integrations using RESTful architectures.
- Strong understanding of SQL and relational database design (e.g., Microsoft SQL Server).
- Proficiency with automated testing frameworks (xUnit, NUnit, JUnit, PyTest).
- Solid experience with CI/CD pipelines, Git, and modern DevOps practices.
Front end skills:
- Proficiency in JavaScript and TypeScript.
- Strong experience with React and/or Angular frameworks.
- Deep understanding of HTML5, CSS3, and responsive UI/UX principles.
- Proven ability to integrate front-end applications with back-end RESTful services and APIs.
- Experience with front-end testing tools such as Testcafe, Playright or Cypress.
- Comfort with modern build tools and workflows (Webpack, npm, etc.).
Leadership and soft skills:
- Proven experience mentoring and supporting junior team members.
- Strong analytical, architectural, and problem-solving abilities.
- Excellent communication skills — able to explain complex technical concepts clearly.
- High sense of ownership and accountability for deliverables.
- Collaborative and proactive approach to teamwork and stakeholder engagement.
- Commitment to quality, performance, and maintainability.
Preferred qualifications:
- Experience with cloud platforms (AWS, Azure, or GCP).
- Familiarity with containerization (Docker, Kubernetes) and modern deployment automation.
- Experience implementing Agile/Scrum best practices in development teams.
- Understanding of security, scalability, and performance optimization in distributed systems.
What we offer:
As well as a career in a fast paced environment within a expanding business, we also offer the below benefits as standard:
Wellness fund or Private Medical Insurance (dependent upon role)
Pension
Life Assurance x 3
25 days holiday plus 8 Bank Holidays
Ongoing continual professional development (CPD)
Holiday purchase Scheme up to 5 days
1 paid and 1 unpaid volunteering day
24/7 and 365 Days Employee Assistance Programme
Team and company offsite events
Specsavers eye care voucher
Free Tea, Coffee and fruit every week – Basingstoke office
