Senior Software Developer

Permanent | Competitive Salary + Annual Performance Bonus

Location: London | Hybrid – 1 Day per Week in the Office

We’re partnering with a forward-thinking technology business to appoint an experienced Senior Full-Stack Developer.

This is an opportunity to play a pivotal role in designing, developing and deploying complex software solutions across a variety of projects and industries. You’ll work across data engineering pipelines, backend services, APIs and user interfaces, delivering reliable and scalable systems that solve real business challenges.

The role requires strong software engineering expertise, advanced Python and TypeScript skills, and hands-on experience with cloud deployments, databases and containerisation.

The Opportunity

As Senior Full-Stack Developer, you’ll contribute throughout the software development lifecycle, helping to shape technical solutions from initial design through to deployment.

You’ll combine backend and data engineering expertise with an understanding of frontend development and user experience. Alongside delivering high-quality code, you’ll review the work of others, mentor junior engineers and help maintain strong engineering standards across the team.

Key Responsibilities

You’ll play an important role in delivering reliable, scalable software solutions by:

• Contributing to the design, development and deployment of robust software solutions.
• Promoting engineering best practices throughout the software development lifecycle.
• Architecting and maintaining complex data engineering pipelines, backend services and APIs.
• Reviewing Python and SQL code through Git to support quality, security and engineering standards.
• Supporting cloud-based deployments and infrastructure across platforms such as Azure and GCP.
• Working with Linux scripting and Docker, including storage, volumes and permissions.
• Designing and implementing database solutions using SQL and cloud technologies.
• Optimising application performance, scalability and data integrity.
• Developing complex user interfaces and software integrations using technologies such as React.
• Supporting the design and implementation of frontend applications with a strong focus on user experience.
• Troubleshooting and improving existing systems.
• Identifying technical risks and contributing to project planning and task management.
• Mentoring junior engineers and encouraging knowledge sharing across the team.
• Communicating technical concepts and project outcomes through documentation, calls and presentations.
• Keeping up to date with emerging technologies and recommending improvements where appropriate.

About You

You’ll be an experienced software engineer with strong full-stack development capabilities and the confidence to contribute across backend services, data engineering and frontend applications.

You will also have:

• Strong experience writing maintainable production code in Python and TypeScript.
• Proven experience building complex user interfaces and software integrations using React or similar technologies.
• Strong knowledge of JavaScript, HTML and CSS.
• A good understanding of programming concepts, data structures, algorithms and HTML DOM components.
• Experience working with browser and web APIs, including HTML Canvas, Drag and Drop, Server-Sent Events and WebSockets.
• Strong SQL skills and experience developing database solutions.
• A good understanding of cloud deployment, ideally across Azure or GCP.
• Advanced Docker skills, including experience with storage, volumes and permissions.
• Experience using Git, GitHub or Azure DevOps within collaborative development environments.
• Confidence managing complex branching and merging scenarios using feature branches and pull requests.
• Experience reviewing commits and supporting automated testing through CI/CD pipelines.
• The ability to understand, review and improve code written by others.
• Proven experience presenting technical concepts to stakeholders.
• Strong written and verbal communication skills.
• The ability to work independently and collaboratively within a distributed team.
• Experience guiding and mentoring other engineers.
• Excellent problem-solving, organisational and time-management skills.
• High attention to detail.

Interview Process:

• Stage 1: 20-minute video call with a member of the hiring team.
• Stage 2: 45-minute live coding task.
• Stage 3: 90-minute face-to-face interview at the London office.

Why Apply?

This is a fantastic opportunity to join a collaborative, forward-thinking environment where you’ll have autonomy, work with a wide range of technologies and contribute to varied projects across multiple industries.

In return, you’ll benefit from:

• A competitive compensation package with an annual performance bonus.
• 26 days of annual leave, plus eight bank holidays and your birthday off.
• Bupa private healthcare.
• Enhanced family leave.
• A £1,000 annual professional development budget.
• Flexible hybrid working, with one office day per week.
• The option to work remotely from anywhere in the world for up to four weeks each year.
• A high-spec Windows machine or MacBook.
• Free snacks and drinks.
• Regular team socials.
• A supportive, entrepreneurial environment with genuine autonomy and development opportunities.

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.

By applying you are confirming you are happy to be added to the Addition Solutions mailing list regarding future suitable positions. You can opt out of this at any time simply by contacting one of our consultants.