Sr. Fullstack Engineer

Job Summary:

We are seeking a Senior FullStack Engineer to own a product area end to end - design it, build it, andrun it in production. You will set the engineering standard for a squad of fourto six engineers, lead the modernisation of existing ASP.NET MVC systems intomodular ASP.NET Core services, and act as the technical counterpart to productowners and client stakeholders.

This role is deliberatelyhands-on. You are expected to write and review code, make architecturedecisions you can defend on cost and risk, and set how the team works with AIcoding assistants and LLM-based features so that quality, security and IP are nevertraded for speed.

Key Responsibilities:

·       Own one or more services end to end - architecture,implementation, deployment, monitoring and production support.

·       Design .NET Core service architecture - API contracts andversioning, domain and service boundaries, async messaging, caching, andresilience patterns (retry, circuit breaker, idempotency).

·       Lead the modernisation of legacy ASP.NET MVC applications into modular ASP.NET Coreservices using a strangler-fig approach, with a migration sequence the businesscan absorb.

·       Own the SQL Server data layer at scale - data modelling,indexing strategy, partitioning, safe production migrations, and the call onwhen to cache, denormalise or offload.

·       Set the frontend standard in Angular or React - application andcomponent architecture, a typed API client layer generated from the APIcontract, predictable state management (signals and RxJS, or hooks and astore), code splitting and lazy loading, enforced performance budgets, and anaccessible reusable component library.

·       Design and integrate AI / LLM capabilities into enterpriseapplications - retrieval and grounding, structured outputs, token and cost budgeting,latency and fallback behaviour, PII boundaries, and evaluation before release.

·       Define how the team uses AI coding assistants - repository-levelinstructions, review standards for AI-generated code, and guardrails thatprotect quality, security and client IP.

·       Own the non-functional requirements - security (OAuth 2.0 /OIDC, Microsoft Entra ID, RBAC, secrets and certificate management),observability, performance and cloud cost.

·       Run and improve CI/CD - build, test and security gates,environment promotion, slot or blue-green releases, and a rollback path thathas actually been tested.

·       Lead incident response for owned services - triage,mitigation, root-cause analysis, a written post-mortem and follow-through onthe actions.

·       Mentor three to five engineers - design reviews, pairing, codereview, and raising the throughput of the team rather than only your own.

·       Work directly with product owners and client stakeholders - scope, estimate,sequence, and push back with evidence when a plan does not hold.

·       Contribute to solution design and pre-sales - effort estimates,architecture views and technical responses for new opportunities.

Mandatory Requirements:

·       8+ years of professional software engineering experience, including at least threein a senior, lead or architect capacity.

·       Deep .NET Core / ASP.NET Core expertise - advanced C# (async andconcurrency, memory and performance profiling), dependency injection,middleware, minimal APIs and MVC controllers.

·       Proven REST API design at enterprise scale - versioning, contracts,idempotency, pagination, rate limiting and backward compatibility.

·       Strong SQL Server - data modelling, indexing strategy,execution-plan analysis, stored-procedure tuning and zero-downtime migrations.

·       Entity Framework Core in depth, including where to drop to raw SQLor Dapper and why.

·       Advanced TypeScript, with architectural-level experience inAngular 16+ or React 18+ - application and module structure, state management (RxJSand signals, or hooks, context and a state library), rendering and re-renderbehaviour, and build and bundle optimisation.

·       Hands-on Azure - App Service or Container Apps, Functions, AzureSQL, Service Bus, Key Vault, Entra ID and Application Insights.

·       Ownership of CI/CD pipelines in Azure DevOps or GitHub Actions,including automated testing and security scanning.

·       Application security - OWASP Top 10, authentication andauthorisation design, secrets handling and data protection.

·       Demonstrated production ownership - you have carried a system youdesigned through real incidents and change.

·       A track record of mentoring engineers and running design andcode reviews.

·       Confident client-facing communication - able to present adesign and its trade-offs to a non-technical stakeholder.

Good-to-Have Skills:

·       Working knowledge of both Angular and React - our client estate usesboth, and you may be asked to set the standard in either.

·       Micro-frontends or module federation, and server-siderendering (Angular Universal or Next.js) where it earns its place.

·       Microservices and event-driven architecture - Service Bus, Kafka,outbox pattern, eventual consistency.

·       Kubernetes / AKS or Azure Container Apps in production.

·       Infrastructure as Code - Bicep or Terraform.

·       Python for data processing, automation or AI services.

·       Hands-on LLM engineering - RAG pipelines, vector stores, toolcalling and agentic patterns, MCP servers, and evaluation harnesses.

·       Multi-tenant SaaS design, including data residency andsovereignty constraints.

·       Regulated-domain exposure (BFSI, legal, healthcare) and theaudit, traceability and compliance expectations that come with it.

·        Experience in a consulting or client-facing delivery model