At a Glance
- Tasks: Own and enhance a key B2B customer portal while integrating cutting-edge technology.
- Company: Join a forward-thinking energy company focused on innovation and collaboration.
- Benefits: Competitive salary, enhanced pension, private medical insurance, and fun perks.
- Other info: Enjoy a supportive culture with career growth and community-focused events.
- Why this job: Make a real impact in a modernising business with exciting AI projects.
- Qualifications: Strong experience in C#, .NET, and building REST APIs.
The predicted salary is between 50000 - 65000 £ per year.
Addition partners with energy leaders to help bring in people who make technology work for real customers. This role sits at the centre of that mission—owning a key customer-facing platform and helping build new internal capability as the business modernises toward a more AI-enabled way of working.
Location: Herfordshire, United Kingdom
Industry: Energy / Utilities (B2B)
What You’ll Be Doing:
- Take primary ownership of the B2B customer portal and its connected APIs and integrations.
- Build and enhance RESTful back‑end services and business logic using C# and ASP.NET.
- Maintain and improve the integration layer across core systems, while keeping the platform stable and secure.
- Support delivery through a sensible, agile SDLC—writing quality tests and collaborating closely with analysts and data owners.
- Help shape the direction of the internal development function, including modernisation work and the adoption of AI tooling.
Main Skills Needed:
- Senior .NET delivery: Strong, hands‑on experience with C# and .NET (Framework), delivering production‑grade applications with real ownership.
- API & service architecture: Confident building REST APIs and service‑based architectures, with experience across UI and back‑end (e.g., Razor Pages/MVC).
- Databases & integration: Solid Microsoft SQL Server skills (optimisation, stored procedures, schema design) and comfort working with legacy environments.
- Azure & Linux hosting: Experience deploying applications in Microsoft Azure, including Linux‑hosted environments and relevant Azure services.
- Engineering best practice: Proficient with Git/GitHub (reviews, branching strategies) and working in agile teams using Jira/Confluence.
What’s in It for You:
- A competitive salary plus a strong benefits package, including enhanced pension, private medical insurance, and life insurance & income protection.
- Career progression as the internal development function grows—plus genuine visibility with technical decision‑making.
- Extra touches that support day‑to‑day wellbeing: day off on your birthday, free parking, and fresh fruit/snacks/breakfast.
- A culture built on collaboration and empowerment, with a real focus on continuous learning.
- Profit share and social energy: amazing company parties and a community‑focused office environment.
We are an equal opportunity employer and value diversity at our company. We do not discriminate on the basis of race, religion, colour, national origin, gender, sexual orientation, age, marital status, veteran status, or disability status.
Senior Developer in England employer: Addition+
At Addition, we pride ourselves on being an exceptional employer, particularly for our Senior Developer role in Hertfordshire. Our collaborative work culture fosters continuous learning and empowerment, while our strong benefits package—including enhanced pension and private medical insurance—ensures that our employees feel valued and supported. With ample opportunities for career progression and a focus on modernising our internal development function, we offer a unique environment where technology meets meaningful impact in the energy sector.
StudySmarter Expert Advice🤫
We think this is how you could land Senior Developer in England
✨Join Local Tech Meetups
Get out there and mingle with fellow developers by joining local tech meetups. It’s a fantastic way to meet people who might be working at Addition+ or know someone who does. Plus, you can pick up some trendy tech skills and trends while you're at it!
✨Contribute to Open Source Projects
Show off your coding chops by jumping into open-source projects. Not only does this give you practical experience, but it also gets you noticed in the dev community. You'll create a killer portfolio that speaks volumes about your skills to Addition+.
✨Tap into Online Developer Communities
Don’t underestimate the power of online developer communities like GitHub, Stack Overflow, and even Reddit. Participate in discussions, share your projects, and build your visibility. We can often find opportunities through these channels that can lead to a full-time gig at companies like Addition+.
✨Explore Job Boards Specifically for Tech Roles
Keep your eyes peeled on job boards that focus on tech roles. Sites like TechCareers or Stack Overflow Jobs can often have listings for companies like Addition+ that might not show up on broader job sites. Make it a habit to check these regularly, and don’t hesitate to apply directly through our website!
We think you need these skills to ace Senior Developer in England
Some tips for your application 🫡
Show off your coding skills:When applying for a software engineering role, it's super important to showcase your coding skills. Make sure your CV includes your tech stack, any relevant programming languages you’re comfortable with, and examples of projects you've worked on. If you have a GitHub profile, link it up! We love to see code in action.
Tailor your portfolio:For a full-time role, we’d expect to see some solid examples of your work in your portfolio. Make sure to include at least two or three projects that highlight your problem-solving skills and your ability to work with different technologies. Focus on the projects that are most relevant to the position at Addition+.
Craft a killer cover letter:Your cover letter is your chance to stand out—make it personal! Explain why you want to work at Addition+ and how your skills align with the role. Show us your passion for software development. We dig enthusiastic candidates who understand the value of collaboration and continuous learning!
Be clear and concise:When it comes to writing your CV and cover letter, clarity is key. Avoid jargon that could confuse us and stick to simple, direct language. Highlight your achievements with quantifiable results where possible, and keep everything easy to read. A well-organised application goes a long way!
How to prepare for a job interview at Addition+
✨Brush Up on Your Coding Skills
For a full-time software engineering role, it's crucial that we stay sharp with our coding abilities. Expect technical questions that might involve solving problems on the spot or discussing algorithms. Practise on platforms like LeetCode or HackerRank to get comfortable with the types of questions that often come up.
✨Know Your Tools and Frameworks
Make sure we’re well-acquainted with the tools and technologies listed in the job description. Familiarise ourselves with any specific frameworks or programming languages mentioned. If Addition+ uses React or Node.js, for instance, be ready to discuss how we’ve used them in previous projects or coursework.
✨Showcase Your Projects
Bring along a portfolio that highlights our best work. This could be code samples, GitHub repositories, or any side projects we’ve built. Make sure we can talk through our thought process for each project, especially the challenges we faced and how we solved them—this shows our problem-solving skills in action.
✨Prepare for Behavioural Questions
While technical skills are key, full-time positions also require cultural fit. Be ready to discuss our previous experiences and how we handle teamwork, conflict, and deadlines. Brush up on the STAR method—Situation, Task, Action, Result—to clearly articulate our past experiences when discussing how we've contributed to a team.
