Senior Full Stack Engineer

**About the role**:
We’re looking for exceptionally talented Senior Full Stack Engineers with deep expertise in.NET/C# and WPF to join our growing team.

You’ll also play a key role in mentoring engineers, driving architectural improvements, and shaping engineering practices that ensure performance, maintainability, and innovation.

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**Key Responsibilities**:
**Application Development**
- Build and maintain robust.NET Framework and.NET Core backend services, APIs, and libraries.
- Integrate with cloud platforms (AWS, Azure) for distributed computing and storage.

**Technical Leadership & Collaboration**
- Lead design reviews, code reviews, and architectural discussions to ensure technical excellence.
- Collaborate with product managers, designers, and cross-functional engineers to deliver high-impact features.

**Quality & Best Practices**
- Champion best practices including SOLID, DRY, KISS, and test-driven development (TDD) to ensure code quality and building of new features.
- Leverage AI-assisted tools (e.g., GitHub Copilot, Claude Code) to streamline development and accelerate feature delivery.
- Perform code refactoring, increase test coverage, and improve legacy codebases.
- Utilise dependency injection frameworks (e.g., Autofac) to write clean and decoupled code.

**Problem Solving & Innovation**
- Tackle complex technical challenges across frontend and backend systems.
- Design solutions with a strong emphasis on asynchronous programming, multithreading, and regular expression optimisation.
- Continuously improve system performance and developer experience through innovation and tooling.

**What You Bring**:

- 5+ years of professional experience with.NET and C# across frontend and backend development.
- Deep expertise in WPF, including XAML, data binding, custom controls, UI animations, and MVVM.
- Proficient in both.NET Framework and.NET Core.
- Familiar with dependency injection, modular architectures, and reusable components.
- Strong understanding of multithreading, async/await, and asynchronous design patterns.
- Experienced with regular expressions, especially in parsing or document-focused workflows.
- Experience working with Visual Studio, JetBrains Rider, ReSharper, and modern DevOps pipelines.
- Experience with AI-assisted coding tools (e.g., GitHub Copilot, Claude Code) to accelerate development.
- Familiar with relational databases (e.g., PostgreSQL) and RESTful APIs.
- Strong grasp of Git and version control best practices.
- Strong communication, collaboration, and problem-solving skills.
- Comfortable in a fast-paced, agile environment.

**Nice to have**:

- Prior experience in product-centric or startup environments.
- Experience with VSTO Word Add-Ins.
- Exposure to other AI-powered developer tools and workflows.
- Familiarity with modern cross-platform frameworks like.NET MAUI, Blazor, or Avalonia.
- Understanding of cloud-native design, distributed systems, and DevOps best practices.

**What we can offer you**:
**Competitive Salary**
- We offer a highly competitive salary that reflects your skills, experience, and contributions.

**Impact & Growth**
- Join a fast-growing startup where your ideas matter; experiment, innovate, and see your work come to life.

**High-Performance Culture**
- Work in a truly meritocratic environment alongside ambitious, driven professionals who push each other to excel.

**Prestigious Partnerships‍**
- Collaborate with some of the world’s top law firms, financial institutions, and multinational corporations.

**Prime London Location & Hybrid Flexibility‍**
- Enjoy a vibrant office in the heart of Aldgate with the option to work in a hybrid environment. We tend to come into the office 2-3 times a week, although you can come in more

**Ongoing Learning & Development‍**
- Access top-tier training, mentorship, and continuous support to advance your career.

**Time Off‍**
- Enjoy 25 days of holiday per year, plus UK bank holidays, to recharge and unwind.

**Pension Plan‍**
- Secure your future with our competitive pension scheme.

**Private Healthcare‍**
- Access to Vitality healthcare, including dental and optical.

**Flexible Working‍**
- Work in a way that suits your lifestyle, with the freedom to balance professional and personal priorities.

**Enhanced Parental Leave**
- We support working parents with generous parental leave policies that go far beyond statutory requirements.

**Cycle to Work Scheme‍**
- Save on a new bike and accessories while promoting a healthier, more sustainable commute.

**Workplace Nursery Scheme‍**
- Saving working parents lots of money through our salary sacrifice scheme

**Top-Quality Equipment‍**
- Get the tools you need to perform at your best, from cutting-edge tech to ergonomic office setups.

**About Definely**:
At Definely, we’re on a mission to simplify the way legal professionals access and understand complex information in legal documents. Trusted by a global community of customers, our LegalTech solutions int