javascript jobs in London

Senior Developer (AI-Augmented Team)

Why work for Engage?

We’re Engage - one of the UK’s leading education recruitment agencies, having proudly expanded into the EdTech space and shaking up the way things are done. We are now looking to appoint someone to be part of the team delivering our roadmap.

Officially ranked the 7th best recruitment company to work for in the UK, we’re recognised for delivering world-class employee engagement.

Our mission is simple: we help schools hire brilliant staff, and we help education professionals find roles they truly love.

Role Summary

We are seeking an experienced, hands-on Senior Software Engineer to join our onshore team and partner closely with our Lead Software Engineer. You will utilise agentic AI coding tools to amplify the velocity and quality of your work delivering for our enterprise platform, while applying critical judgment and Human-in-the-Loop (HITL) discipline to keep complex systems stable and structurally sound.

Key Responsibilities

1. Architectural Modernisation and Re-platforming

• Execute the continued migration from ASP.NET Framework 4.8.1 Web API to modern .NET (.NET 10). Optimise query performance across SQL Server and ORMs such as Entity Framework.
• Standardise the core application infrastructure by implementing standard middleware (e.g., JWT middleware) & replace existing authentication and token plumbing.
• Implement long-running processes using out-of-band message-based architecture (Azure Service Bus).

2. Delivery, CI/CD and Cloud

• Work within our Azure DevOps CI/CD pipelines and Git repositories, helping keep build, PR validation, and deployment fast, repeatable, and trustworthy as the single safe path to production.
• Deploy and operate across our Azure platform and contribute to our growing Infrastructure-as-Code practice (Bicep).
• Help reduce technical, platform and infrastructure debt incrementally.

3. AI-Augmented Craft, Quality, and Testing

• Use AI coding assistants to accelerate delivery while applying strict HITL validation - you own, understand, and can defend every line that lands, AI-generated or not, never letting AI fluency substitute for fundamental understanding.
• Help raise the team's code-quality bar: adhere to coding standards, keep static-analysis signals clean, and treat code quality and test gates as non-negotiable.
• Drive meaningful, well-targeted test coverage across the backend system to verify replatforming efforts.

4. Engineering Judgement and Collaboration

• Use your experience to foresee problems and weigh trade-offs across scalability, maintainability and security. Design in redundancy and backup plans rather than discovering the need for them in production.
• Partner with the Lead Software Engineer to turn architectural direction into shipped, well-documented work and mentor less-experienced engineers.
• Cross-functional collaboration with team members and stakeholders across Engage to ensure requirements are met using tools such as Jira and Confluence.

Required Skills and Experience

• Platform Expertise: 5+ years strong, hands-on C# / .NET experience across both Framework and modern .NET. Excellent knowledge of SQL Server query performance and ORMs such as Entity Framework, with real experience evolving or migrating large, long-lived solutions toward modern .NET.
• Architectural Proficiency: Comfortable applying modern design patterns, decoupling tightly-coupled code, introducing message-based asynchronous processing, and designing for testability.
• Cloud and Delivery: Practical experience deploying and running applications on Azure or similar, and working within CI/CD pipelines (Azure DevOps YAML schema experience preferred), including environment promotion, approval gates and deployment slots.
• AI Fluency: Demonstrated judgment and willingness to leverage AI coding assistants (e.g. Claude Code, Cursor, GitHub Copilot) to accelerate productivity while exercising critical judgment to verify and curate AI output.
• Quality Management: Experience with coding standards, maintaining code quality and automated test gates, and following meaningful test coverage practices. Experience with test frameworks (e.g. xUnit).
• Mindset: Ability to balance programmer optimism (the belief that a solution exists) with the realism needed to foresee and ensure potential long-term architectural suitability.

Preferred Skills and Experience

• React experience and JavaScript/TypeScript fluency.
• Modern .NET hosting: Aspire, Docker/containerisation and Azure Container Apps.
• Infrastructure-as-Code with Bicep (or Terraform / ARM).
• Observability / Telemetry (e.g. OpenTelemetry, Application Insights, Sentry).

Pay: £70,000.00-£75,000.00 per year

Benefits:

• Company pension
• Paid volunteer time
• Work from home

Work Location: Hybrid remote in Watford