Senior Backend Engineer

At Believ, formerly known as Liberty Charge, we believe sustainable transport should be accessible to everyone. We’re a Charge Point Operator (CPO) on a mission to create the UK’s most reliable electric vehicle charging network that doesn’t cost the earth and leaves no one behind. We work closely with local authorities and businesses to deliver reliable, high quality charging networks at pace, at scale and at zero cost.

We offer all the advantages of being a scale‑up business, but with the added security and long‑term backing from well‑known parents – Liberty Global and Zouk Capital. You’ll be joining this exciting journey at the start of our scale‑up phase, and work with us to hit the ambitious targets our shareholders have set. You’ll become part of a passionate and supportive team in a fast‑paced, dynamic and result‑driven environment.

We are seeking an experienced Senior Software Engineer (Backend) to lead the development of our in‑house Charge Point Management System (CPMS) and customer‑facing app and web portal. Reporting into the Head of Engineering, this role will be responsible for enhancing these platforms to achieve feature parity with the incumbent SaaS solution. Following the migration, the focus will be on designing and implementing innovative features to create a market‑leading, scalable, and secure platform.

• Backend Development: Develop scalable and secure applications using Python with FastAPI on the backend. Design and implement reusable, modular code for both client and server‑side components.
• API & Microservices Design: Define and build RESTful APIs and microservices using FastAPI that are efficient, secure, and scalable. Create data models with SQLAlchemy for seamless database interaction.
• System Performance & Reliability: Conduct performance profiling and debugging to optimize system speed and reliability. Use containerization tools like Docker for scalable deployments.
• OCPP/OCPI Libraries: Integrate OCPP/OCPI protocols into the CPMS to enable seamless communication with charging hardware and integration with third‑party services like EV roaming and payment service providers.
• Collaboration & Mentorship: Partner with product managers and designers to define technical requirements and ensure alignment with business goals. Mentor junior developers, providing guidance on best practices and code reviews.
• Continuous Improvement: Stay updated with industry trends and implement improvements to ensure the system remains cutting‑edge. Explore new tools & libraries which can improve the system, building prototypes to test. Integrate feedback from customers into the product, and define and deliver metrics to improve the product.

At Believ, we are building a culture that attracts and retains the best talent. We are a dedicated and high‑performing team, accustomed to working at pace in an ever‑evolving industry, and we are looking for people who are as passionate as us about cutting carbon emissions and providing cleaner air for all.

• Knowledge & Experience: Proven track record of delivering scalable and secure applications. Experience working with cloud‑based environments, particularly AWS. Familiarity with performance optimization and debugging tools. Knowledge of database design principles and SQL optimization.
• Engineering Mindset: Ability to understand and consider the broader business context and long‑term implications of technical decisions. Willingness to take ownership, innovate, and proactively seek opportunities to drive impact beyond immediate tasks. Strong focus on delivering solutions that align with business goals and address real‑world challenges effectively. Commitment to delivering exceptional user experiences by prioritizing customer needs and feedback throughout the development process. Demonstrate enthusiasm, resilience, and a can‑do approach to tackling challenges and driving success.
• Skills & Abilities: Expertise in Python, FastAPI, SQLAlchemy. Proficiency with containerization tools like Docker and infrastructure‑as‑code tools such as Terraform. Familiarity with OCPP/OCPI protocol integration. Experience designing scalable APIs and microservices. Excellent communication skills and a collaborative mindset.

• Competitive salary and bonus scheme.
• 25 days’ annual leave, plus the usual 8 UK Bank Holidays and the option to purchase up to 5 additional days per year.
• Access to wellbeing and mental health benefits such as the Calm app, personal medical insurance, critical illness cover, dental, optical & travel insurance, income protection and life assurance.
• Pension contribution matched up to 10%.
• Access to our car benefit scheme and cycle to work scheme.
• Access to our online learning platform to continue to develop and grow your career with us.
• 16 hours a year Volunteer Time Off to support causes that are important to you.
• Virgin Media / O2 discounts and offers.
• Access to VIP Arena Suites at the O2 Arena (London) and First Direct Arena (Leeds).
• Enhanced parental leave policies.

The business is currently based in our office in Southwark. The position is full time, hybrid with 3 days (Tuesday, Wednesday & Thursday) based in the office. Believ is an equal opportunity employer. We embrace diversity and are committed to creating an inclusive environment for our people. We will ensure that individuals with disabilities are provided reasonable accommodation to participate in the job application or interview process, to perform essential job functions, and to receive other benefits and privileges of employment. Please contact us to request accommodation.