Become a crucial part of our innovative team!

Role title: Lead Software Engineer
Reporting to: VP of Engineering
Key Stakeholders: Platform Team, UK & NL Engineering teams, Product Teams
Contract Type: Permanent
Start Date: As soon as available
Location: Hybrid – on site in either our `s-Hertogenbosch or London office 2-3 days per week; hybrid/remote for the remaining days

Over the past 30 years, Tax Systems Limited has become a leading supplier of corporation tax and regulatory reporting software and services to large corporates and accountancy firms in the UK and Ireland. We serve over 40% of the FTSE-100, 80%+ of the top UK accounting firms and work closely with HMRC.

Our recent acquisition of TaxModel, based in the Netherlands, means we now offer international tax solutions covering tax provision, transfer pricing and Pillar 2. These products will further accelerate our ambitious growth plans alongside the launch of two additional products in 2024.

Our portfolio of SaaS and AI solutions automate and simplify complex tax processes and deliver enhanced value through better management of financial data. All of this is underpinned by market leading levels of customer service, referenced by our on going CSAT score of 9.7.

We are a private equity backed business of c.140 people with a family feel and a connected culture. This is reflected in our strong quarterly engagement scores (9 out of 10 people would recommend us to friends and family) and positive Glassdoor results (100% CEO approval).

Tax Systems serves a diverse enterprise customer base—ranging from Fortune 500 multinationals to fast‑growing mid‑market organisations—all of whom rely on our cloud‑native software to meet critical tax‑reporting deadlines. These customers demand rock‑solid compliance, security, resilience, and raw performance every single release.

Built on .NET 8+, Azure PaaS, and fully automated CI/CD pipelines, our engineering culture emphasises rapid delivery with uncompromising quality. As a Lead Software Engineer you’ll play a leading role in the design, development, and maintenance of the backend services that power our SaaS products, automating infrastructure with Terraform, and wiring everything into one click pipelines—from commit to live dashboards. Your work will shape engineering standards and cloud operations across the entire product portfolio.

If you thrive on deep C# engineering, DevOps craftsmanship, and seeing your work reach production quickly, this role gives you the runway and autonomy to make a significant impact.

• Feature delivery – build product capabilities (LLM integrations, workflow automation, complex calculations) in C#/.NET 8+.
• API & data design – design practical RESTful APIs, craft clean domain models, build performant EF Core queries, and make endpoints secure-by-design and ready to scale on Azure.
• DevOps & CI/CD – design YAML pipelines in Azure DevOps; integrate tests, IaC (Terraform), and blue-green releases.
• Architecture patterns – implement vertical slice features and help maintain modular boundaries for a maintainable codebase.
• Cloud component selection – shape our use of cloud services to optimise cost, performance, and resilience.
• Authentication & security – implement Azure AD, OAuth2/OIDC (PKCE), JWT based- authorisation; uphold OWASP best practices.
• Quality & reviews – lead code reviews, pair programming, and contribute to RFCs/ADRs.
• Observability – add metrics, traces, and logs; define SLIs/SLOs with platform engineers.

• Practical coding ability: 6+ years of professional C#/.NET development, including recent projects on .NET 8 or later, proficiency in additional languages such as Typescript, Rust, Go, Python, or Ruby is not essential, but is desirable.
• Experience delivering and maintaining distributed systems: At least 2 prior roles have coupled a deep theoretical understanding of the challenges building and running resilient distributed systems on the cloud with extensive practical experience
• Proven delivery of enterprise SaaS on Azure: Strong CI/CD and IaC practices in addition to practical knowledge of Azure services such as App Service, Functions, Container Apps, AKS, APIM, Service Bus, and Entra.
• Proven leader and role-model: Provide leadership to colleagues across the product development lifecycle through example as well as through coaching and pair-programming.
• Deep knowledge of Entity Framework Core, SQL Server query performance tuning, and data modelling.
• Cloud & Distributed System design patterns: Broad knowledge and experience with design patterns relevant to distributed systems and cloud deployment like pub-sub,

The major parts of our server-side Tech Stack are listed below, you needn’t have experience in all of this, but if you do, that’s great!

• Coding: .NET 8+, C#, Entity Framework Core, REST/JSON
• Cloud & IaC: Azure (App Service, Container Apps / AKS, Functions, Azure SQL, Blob Storage, Key Vault, Front Door, APIM, Gateway, Fabric, ADF, Monitor), Terraform, GitOps.
• Auth & Security: Entra ID (Azure AD), OAuth2/OIDC, PKCE, JWT, Managed Identities, Key Vault, OWASP Top 10
• Testing & Observability: xUnit, Playwright, Grafana k6, Azure Load Testing, JMeter, Gatling, Application Insights, Azure Monitor, OpenTelemetry, New Relic
• CI/CD Tooling: Azure DevOps Pipelines (YAML), Docker, Azure DevOps Artifacts (NuGet/NPM).
• Networking & Security: Azure VNet, Private Link, NSG, WAF / Application Gateway, Azure AD, OAuth2 / OIDC, SAML, JWT, Managed Identities, OWASP Top 10
• Data & Messaging: Azure SQL, Azure Blob Storage, Event Grid/Service Bus, Redis (design & ops familiarity).
• AI Tools in Development: Use AI-powered code completion tools (e.g., GitHub Copilot, Cursor, Windsurf), apply prompt engineering techniques for architectural design and debugging, and employ AI-driven solutions for testing and documentation throughout the product development lifecycle.

Tax Systems is committed to adhering to all relevant Information Security legislation and building a reputation that prioritises protecting customer information entrusted to it. Expectations are as follows:

• To read and adhere to Tax Systems and role specific Information Security Policies,
• Treat all information whether its external or internal appropriately under our Tax Systems classification scheme
• Keep Information Security in mind during daily activities and remain vigilant to possible threats and incidents.