Senior Full Stack Developer

Role: Senior Full-Stack Developer

Location: London (Hybrid – 3 days in-office per week)

Start Date: ASAP

Day Rate: £550

About the Company

A fast-growing UK-based organisation is building software to support the delivery of high-integrity environmental solutions. Their clients include major developers and infrastructure providers, and the company is scaling rapidly. A core focus is on developing reliable internal tooling for pricing, compliance, quoting, and stock availability.

The Opportunity

They’re looking for a hands-on Senior Full-Stack Engineer to take ownership of the first production-ready version of their quoting and automation platform. This includes database design, backend development, and a robust front-end that internal teams can rely on daily. You’ll be responsible for architecture, implementation, deployment, and ensuring reliability from day one.

Key Responsibilities

Quoting & Optimisation Engine

• Implement logic for pricing BNG/NN units, including rule-based calculations (e.g. adjacency, trading caps).
• Build systems that intelligently allocate available stock based on multiple constraints (e.g. location, pricing).
• Ensure pricing models are fully traceable and auditable for compliance.

Automation & Data Pipelines

• Automate tasks like stock updates, KPI reporting, and pricing refreshes.
• Refactor internal data sources into structured, versioned SQL-backed models.
• Develop helpers to process geographic and regulatory data layers (e.g. GIS overlays).

User-Facing UI

• Build a reliable, performant front-end for non-technical commercial users.
• Develop middleware to surface business insights.
• Implement role-based access control, usage tracking, and exportable outputs (PDF/CSV).

Platform Engineering & Security

• Set up authentication (SSO preferred), RBAC, audit trails, and security best practices.
• Own CI/CD pipelines, infrastructure as code, and system monitoring from the start.

Tech Stack & Experience

Essential

• Strong full-stack background: TypeScript with React (or similar), Python (FastAPI) or Node.js (NestJS).
• Data: PostgreSQL preferred; solid experience with schema design, migrations, and performance tuning.
• Cloud/DevOps: Azure or AWS, Docker, GitHub Actions, IaC tools (Terraform/Pulumi).
• Security-first mindset: OAuth/OIDC, token auth, logging, and secure architecture.
• Testing & Docs: Confident with writing tests, documenting APIs, and delivering production-grade systems.

Bonus Points

• Experience with Streamlit or similar tools (used internally for prototyping).
• Background in GIS and mapping tools (Leaflet, Mapbox, shapefiles).
• Experience in algorithmic optimisation (e.g., linear/mixed-integer programming).
• PDF/document generation from templates (WeasyPrint, Playwright, etc.).
• Familiarity with regulated industries or systems requiring audit-grade traceability.