# Senior Software Engineer (C# / PostgreSQL / AI-Native)

> zendbox · Paddock Wood, United Kingdom (Hybrid) · Full-time · Posted 2026-02-16

**Salary:** Up to GBP 75,000

**Workplace:** hybrid

**Department:** Tech

## Description

We have a working AI Proof of Concept (PoC) that proves our vision; now we need the engine that powers the product at scale. As our **Senior Software Engineer**, you will be the lead architect and primary builder of our production-grade, AI-first .NET platform.

Working directly with the Head of Technology, you will be responsible for moving us from experimental scripts to a robust, observable, and scalable **Agentic AI Architecture**. We are a high-velocity team that values "Ship Fast, Fix Fast." We utilize agentic AI tools like Claude Code to bypass the boilerplate, freeing you to focus on the high-value architectural challenges of a production-ready system.

**What You’ll Do**

-   **Productionize AI Workflows:** Transform raw AI prompts and experimental logic into resilient production code using .NET 10/C# 14.
-   **Architect Agentic Systems:** Design and build the "Agent Loops" (Planning → Execution → Observation) that allow our AI to interact reliably with our internal databases and external APIs.
-   **Build for Reliability:** Implement "Evals" and Guardrails to manage the non-deterministic nature of LLMs, ensuring outputs are safe, accurate, and consistent for our users.
-   **Cloud Infrastructure:** Partner with the Head of Tech to design and deploy the Azure/AWS infrastructure required to support high-concurrency AI workloads, focusing on latency and cost-per-token optimization.
-   **AI-First Tooling:** Lead the team in adopting and optimizing AI-assisted development workflows (Claude Code, Cursor, etc.) to maintain our 10x velocity.
-   **Strategic Evolution:** Collaborate on the long-term technical roadmap, identifying when to use fine-tuned Small Language Models (SLMs) vs. Frontier LLMs.

## Requirements

### **The "Must-Haves"**

-   **C# Mastery:** You are an expert in the modern **.NET** ecosystem.
-   **PostgreSQL Expert:** You know how to design schemas, optimize queries, and leverage Postgres for high-performance applications.
-   **Architectural Thinker:** You can look at a PoC and know exactly what it needs to survive 100x the current load.

### **The "Bonus Points" (Will make you stand out)**

-   **Blazor:** Experience with Blazor (Server or WebAssembly) for building real-time UIs.
-   **Azure ML:** Any exposure to **Azure Machine Learning** services or deploying ML models into a production pipeline.
-   **AI Workflow:** You already use **Claude Code**, Cursor, or GitHub Copilot in your daily flow.

## Apply

[Apply at zendbox](https://apply.workable.com/zendbox/j/E769839477/apply)

---
Powered by [Workable](https://www.workable.com)