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- Tasks: Lead the development of a greenfield SaaS product using C# and AWS.
- Company: Dynamic tech start-up focused on innovative solutions.
- Benefits: Competitive pay, flexible work options, and opportunities for professional growth.
- Other info: Mentorship opportunities and a culture of high-quality engineering.
- Why this job: Join a cutting-edge team and shape the future of AI-native engineering.
- Qualifications: Deep expertise in C#, .NET Core, and AWS serverless architecture.
The predicted salary is between 80000 - 100000 £ per year.
Reporting to the Director of Engineering, this is a genuinely outstanding contract opportunity for a rockstar Principal C# Engineer to lead the development of a greenfield SaaS product. We’re 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. You’ll need a genuinely Product Centric mindset and approach twinned with experience of AI‑Native Engineering and Agentic Workflow.
Senior–Staff‑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.
Deep data 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. Hands‑on experience with Claude Code and advanced agentic workflows; multi‑agent orchestration, context management, custom commands/skills and scaling AI‑assisted delivery across a team.
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.
Technical leadership; lifting teams through pairing, mentoring, PR review and example. A pragmatic, outcome‑oriented mindset; comfortable with ambiguity, biased to shipping, and able to make sensible calls on scope, sequencing and technical debt.
What You’ll 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.
- Design robust data models and persistence patterns across Aurora RDS MySQL and DynamoDB; choosing the right store for the workload, tuning for scale, and modelling for both transactional and high‑throughput access patterns.
- Build resilient, event‑driven systems using SQS and related AWS messaging primitives; idempotency, retries, DLQs, ordering and clean service boundaries.
- Own each feature’s solution end‑to‑end; partnering with BAs on high‑level problems, then driving product thinking, scoping, trade‑offs and delivery yourself.
- Leverage Claude Code and advanced agentic workflows; orchestrating sub‑agents, managing context, running parallel workstreams and embedding AI‑native engineering patterns into everyday delivery.
- Design clean, well‑versioned, well‑documented APIs that other engineers love to consume; treating developer experience and contract stability as first‑class concerns.
- Shape architecture and technical direction with Principal Engineers; making well‑reasoned decisions on service boundaries, data design, messaging patterns, consistency guarantees and performance.
- Champion a high‑quality engineering culture; test coverage, peer review, CI/CD discipline (GitHub Actions), IaC, secure coding, observability and performance.
- Mentor and up‑level engineers through pairing, PR review, architectural guidance and practical coaching on AI‑assisted development.
Principal C# Backend Engineer - .Net 8/9, AWS (Lambda, SQS), Agentic Workflows (Claude Code), M[...] employer: Smart Sourcer
Contact Detail:
Smart Sourcer Recruiting Team
StudySmarter Expert Advice 🤫
We think this is how you could land Principal C# Backend Engineer - .Net 8/9, AWS (Lambda, SQS), Agentic Workflows (Claude Code), M[...]
✨Tip Number 1
Network like a pro! Reach out to your connections in the industry, attend meetups, and engage in online forums. You never know who might have the inside scoop on job openings or can refer you directly.
✨Tip Number 2
Show off your skills! Create a portfolio showcasing your projects, especially those involving C# and AWS. This gives potential employers a taste of what you can do and sets you apart from the crowd.
✨Tip Number 3
Prepare for interviews by practising common technical questions and coding challenges. Use platforms like StudySmarter to brush up on your knowledge and get comfortable with problem-solving under pressure.
✨Tip Number 4
Apply through our website! It’s the best way to ensure your application gets seen by the right people. Plus, it shows you’re genuinely interested in joining our team and contributing to exciting projects.
We think you need these skills to ace Principal C# Backend Engineer - .Net 8/9, AWS (Lambda, SQS), Agentic Workflows (Claude Code), M[...]
Some tips for your application 🫡
Show Off Your Skills: When you're writing your application, make sure to highlight your experience with C# and .NET Core 8/9. We want to see how you've tackled complex problems and led projects in the past, so don’t hold back on those details!
Be Product Centric: We’re looking for someone with a genuine product mindset. In your application, share examples of how you’ve partnered with BAs or made trade-offs to deliver features that truly meet user needs. Show us you can think like a product owner!
Talk About AWS Experience: Since this role involves AWS serverless architecture, make sure to mention your hands-on experience with Lambda, SQS, and other AWS services. We want to know how you've built resilient systems and what challenges you've overcome in the cloud.
Keep It Clear and Concise: While we love detail, clarity is key! Make sure your application is well-structured and easy to read. Use bullet points if needed, and don’t forget to apply through our website for the best chance of getting noticed!
How to prepare for a job interview at Smart Sourcer
✨Know Your Tech Inside Out
Make sure you’re up to speed with C# and .NET Core 8/9, as well as AWS services like Lambda and SQS. Brush up on your knowledge of event-driven systems and be ready to discuss your experience with architecting distributed REST API microservices.
✨Showcase Your Product Mindset
Be prepared to talk about how you approach product-centric development. Share examples of how you've made trade-offs, prioritised features, and collaborated with BAs to deliver solutions without a traditional Product Owner.
✨Demonstrate Your Leadership Skills
Highlight your experience in mentoring and lifting teams through technical challenges. Discuss specific instances where you’ve led by example, whether through code reviews, pairing, or guiding less experienced engineers.
✨Communicate Clearly and Effectively
Practice articulating complex technical concepts in a way that’s easy to understand. Be ready to ask insightful questions during the interview to demonstrate your ability to shape requirements and translate them into actionable tasks.