Senior Full Stack Engineer

Salary £80k to £85k + Bonus and excellent pension/ benefits

Location: Central London

About the client

Our client is an infrastructure communications technology company providing end-to-end fibre solutions and now Cloud solutions, Wi-Fi, Firewalls/Security, SD WAN, Managed LAN and UC services for businesses and wholesale/carrier/channel organisations across London.

What you will do:

We are looking for a Senior Full Stack Engineer to own end-to-end delivery of critical features, drive architectural excellence, and establish best practices. You ll work hands-on across React, Node.js, and Python services, own our CI/CD and DevOps processes, integrate with network-centric systems, and mentor the wider engineering team as we grow.

Key responsibilities:

• Architect, build & implement scalable features in our React frontend and Node.js / Python backend (FastAPI, Celery)
• Design integrations with network devices, IPAM, monitoring platforms, Wi-Fi authentication systems, CRMs and partnered PropTech tools
• Continually hone and perfect our homegrown DevOps and CI/CD processes by further developing GitHub Actions pipelines, Terraform definitions and observability integrations.
• Ensure quality & reliability: establish testing best practices (unit, integration, end-to-end), conduct code reviews and demand high quality standards
• Shape and refine our cloud-native platform to optimise performance, security and scalability
• Mentor & lead intermediate developers, imparting knowledge and fostering a culture of clean code, peer review and shared ownership.
• Collaborate cross-functionally with product, operations and customer success to translate requirements into robust technical solutions.

A good fit candidate will have:

• 5+ years hands-on as a full stack engineer in a SaaS environment
• Expert in React (hooks, state management, performance)
• Strong backend skills in Node.js (Express) and Python (FastAPI, Celery)
• Deep familiarity with Microsoft Azure (App Services, Functions, networking)
• Proven experience working with network-focused systems (SNMP, IPAM, CLI automation)
• Solid understanding of Auth0 (or similar OAuth/OIDC) and secure authentication flows.
• Skilled with GitHub and GitHub Actions for automated CI/CD.
• Experience with infrastructure as code (ARM templates, Terraform, Bicep).
• Comfortable writing and maintaining tests (unit, integration, e2e).
• Excellent communication, problem-solving skills and ability to thrive in a fast-paced startup.

Desirable Experience:

• Background in network engineering or close collaboration with network operations teams.
• Experience building platform integrations and/or asynchronous automation systems.
• Open-source contributions in related domains.
• You ve worked at an early-stage startup before and understand what hands-on really means.