Senior Full Stack Engineer / Lead

Harvey Nash Group; Greater London; On-site; GBP 90,000 - 130,000; Full time

Job summary

Harvey Nash Group is seeking a Senior Full-Stack Engineer in London to co-lead architecture and build data-driven products for sales, account management, and customer success teams. You will work with Python, TypeScript, AWS, and Terraform across web portals, document generation, and cloud apps processing billions of records.

You'll mentor teammates, collaborate with cross-functional teams, and explore AI capabilities to accelerate tooling and customer touchpoints.

Qualifications

• Expert-level Python development experience in production systems.
• Expert AWS experience including Lambda, S3 and API Gateway.
• Proven track record deploying and managing containerized apps.
• Hands-on with IaC tools, especially Terraform.
• Experience making architecture decisions in fast-paced environments.

Responsibilities

• Architect new full-stack features across API, backend, and frontend.
• Review designs with Analytics Engineers and define integration patterns.
• Write code in Python and TypeScript for infra to UI.
• Evaluate AI tooling and prototypes like LLMs and agent workflows.
• Ensure performance, security and reliability for enterprise deployment.

Skills

Python

AWS

Full-stack

TypeScript

Architecture

Tools

Terraform

Docker

Kubernetes

Next.js/React

AWS Lambda

Job description

Fantastic opportunity to join a world class business.

Job Title: Senior Full-Stack Engineer

Location: UK-London

Overview:

The team builds data-driven products that directly drive revenue growth by transforming how our commercial and customer-facing teams operate. We create innovative data and software tools that sales, account management, and customer success teams use to close more deals, retain customers, and deliver better customer experiences.

As Senior Full-Stack Engineer, you'll co‑lead the technical architecture and development of our entire platform ecosystem: web portals, automated document generation systems, and cloud applications that process billions of records. You'll collaborate on end-to-end technical decisions, from selecting frameworks to designing integrations between BigQuery data pipelines, Salesforce, and enterprise authentication systems. Working in Python, AWS Lambda, Next.js/React, and Terraform, you'll architect high-performance solutions while mentoring team members and contributing innovative ideas for future capabilities.

Your technical decisions directly influence how hundreds of commercial and customer-facing professionals across global business units identify prospects, prioritize opportunities, retain accounts, and deliver differentiated customer experiences. A key part of the role is evaluating and integrating emerging AI capabilities - including LLM-powered features, AI agent frameworks, and MCP servers - to accelerate both internal tooling and customer touchpoints.

You'll join an existing Senior Full-Stack Engineer and share technical ownership of the platform, dividing focus across features and initiatives. You'll work with Analytics Engineers in your team who build the data pipelines powering your applications, sales teams across business units who provide direct feedback, product and commercial teams who understand customer needs as well as data engineers and IT teams who help scale solutions This cross-functional exposure gives you unique perspective on both technology and business context. You'll help scale successful, well-loved tools from MVP stage to enterprise-grade platforms serving new markets, working in a small, collaborative team with startup pace but enterprise resources and mandate.

Responsibilities:

You'll architect new applications and features across the full stack, from designing API endpoints and service architectures to implementing frontend interfaces. Daily work involves reviewing technical designs with Analytics Engineers, making architectural decisions on system integrations, and writing code in Python and TypeScript to implement solutions from infrastructure through user interface.

A typical day includes conducting proof-of-concepts for new tools and technologies, evaluating their fit for the platform architecture, and presenting technical recommendations to the team. This increasingly includes AI-powered capabilities: evaluating LLM APIs (such as Anthropic Claude or OpenAI), building MCP servers to expose internal data to AI agents, and prototyping agentic workflows that automate repetitive commercial processes. You'll investigate and resolve production bugs, optimize web portal performance and rendering efficiency, debug Lambda functions, and refactor components to improve reliability and maintainability. You'll design efficient data movement patterns in the cloud to handle high-volume datasets and ensure applications remain responsive under load.

You'll collaborate with the Product Lead to define technical requirements for new features, propose implementation approaches and estimate development effort. This includes designing integration patterns between systems, implementing authentication and authorization systems for enterprise portals, specifying API contracts, and selecting scalable technologies that can grow with the platform. You'll also spend time on infrastructure work: deploying services via Terraform, configuring CI/CD pipelines, architecting document generation systems, and ensuring applications meet performance and security requirements for enterprise deployment.

Qualifications:

• Expert-level Python development experience building production applications
• Expert-level AWS experience, including Lambda, S3, and API Gateway
• Proven experience deploying and managing containerized applications
• Hands‑on experience with Infrastructure as Code tools, particularly Terraform
• Experience making technical architecture decisions and trade-offs in fast‑paced environments