Lead C# Engineer - Agentic Workflows & AI Engineering, AWS

Lead C# Engineer - Agentic Workflows & Native AI Engineering, .Net 8/9, AWS (Lambda, SQS) OUTSIDE IR35

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Reporting to the Director of Engineering, this is a genuinely outstanding contract opportunity for a rockstar Senior C# Engineer to lead the development of a greenfield SaaS product . Were looking for a best of breed, deeply senior, technically hands-on engineer who thrives in complex problem spaces and fast-moving start-up & scale-up environments. Youll need a genuinely Product Centric mindset and approach twinned with experience of AI-Native Engineering and Agentic Workflow .
Skills Were Looking For:
SeniorStaff-level backend engineer with deep, current expertise in C# and .NET Core 8/9 , capable of architecting and leading the design of distributed REST API microservices at scale.
Authority in AWS serverless architecture; Lambda-first, with strong working knowledge of API Gateway, SQS, Step Functions, EventBridge and IAM, and a track record of shipping production workloads on this stack.
Hands-on experience with Claude Code (or similar) and advanced agentic workflows ; multi-agent orchestration, context management, custom commands/skills and scaling AI-assisted delivery across a team.
Expertise across Aurora RDS MySQL and DynamoDB; schema design, access patterns, indexing, query tuning, single-table vs multi-table trade-offs, and pragmatic thinking around consistency, scaling and cost.
Proven experience designing event-driven systems with SQS and adjacent AWS messaging; idempotency, retries, ordering, DLQs and operational robustness.
Strong API design sensibility ; versioning, documentation, throttling, backwards compatibility and a genuine obsession with developer experience.
A strong product brain ; comfortable operating without a traditional Product Owner, partnering with BAs, making sensible trade-offs, prioritising ruthlessly and owning the solution through to delivery.
Excellent communication skills and comfort with ad-hoc client interaction, able to ask the right questions, shape requirements and translate outcomes into shippable work.
Rigorous engineering standards ; Git-based workflows, trunk-based development, CI/CD (ideally GitHub Actions), IaC (AWS CDK or Terraform), comprehensive testing and secure-by-default coding.
A pragmatic, outcome-oriented mindset ; comfortable with ambiguity, biased to shipping, and able to make sensible calls on scope, sequencing and technical debt.
What Youll Own & Deliver:
Architect, build and ship complex distributed services in C# and .NET Core 8/9 , primarily serverless on AWS Lambda , setting the technical bar for the squad and delivering major feature sets end-to-end.
Build resilient, event-driven systems using SQS and related AWS messaging primitives; idempotency, retries, DLQs, ordering and clean service boundaries.
Leverage Claude Code, advanced agentic workflows and native AI engineering practices; orchestrating sub-agents, managing context, running parallel workstreams and embedding AI-native engineering patterns into everyday delivery.
Own each features solution end-to-end ; partnering with BAs on high-level problems, then driving product thinking, scoping, trade-offs and delivery yourself.
Design clean, well-versioned, well-documented APIs that other engineers love to consume; treating developer experience and contract stability as first-class concerns.
Champion a high-quality engineering culture ; test coverage, peer review, CI/CD discipline (GitHub Actions), IaC, secure coding, observability and performance
£875 - £900 per day. OUTSIDE IR35. 100% remote. xwzovoh 6 months rolling.