Senior Full Stack Product Engineer

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

Job summary

Gravitas Group seeks a Senior Full Stack Product Engineer to drive the development of an AI-enabled SaaS platform in a fast-growing scale-up. You will own features from concept to delivery across web apps, dashboards and services, helping shape product direction.

You will mentor engineers, participate in architecture decisions, collaborate with Product and Data teams, and ensure secure, scalable, and performant systems while maintaining high engineering standards.

Qualifications

• Proficiency in TypeScript, Node.js and React or Angular.
• Experience delivering scalable, high-quality full-stack features.
• Ability to mentor engineers and participate in architecture discussions.
• Hands-on experience with cloud platforms (AWS, GCP or Azure) and scalable systems.

Responsibilities

• Build and deliver scalable, high-quality full-stack features.
• Own projects from discovery through deployment.
• Participate in architecture discussions and code reviews.
• Mentor engineers and foster knowledge sharing.
• Collaborate with cross-functional teams to shape product direction.
• Enhance platform reliability, security, and performance.

Skills

TypeScript

Node.js

React/Angular

System design

Mentoring

Cross-functional collaboration

Tools

NestJS

AWS/GCP/Azure

AI/LLM

CSS

Job description

Senior Full Stack Product Engineer

The Senior Full Stack Product Engineer joins a rapidly expanding SaaS company that is revolutionising how global brands assess digital influence and marketing impact. This role plays a pivotal part in developing a modern AI-enabled platform within a dynamic, scale-up environment.

About the Company

Our client is a venture-backed SaaS organisation specialising in data-driven marketing solutions for major consumer brands and agencies. They focus on leveraging AI, automation, and machine learning to support smarter decision‑making in marketing.

Role Overview

The Senior Full Stack Product Engineer will be responsible for building and delivering high-quality, scalable features across multiple products, including SaaS platforms, AI-powered tools, and internal dashboards. They will work closely with cross‑functional teams, contribute to architecture discussions, and mentor junior engineers. Success in this role involves delivering reliable, secure solutions that influence product direction and meet customer needs.

Key Skills & Experience

• Lead development of full-stack features using TypeScript, Node.js, and React or Angular
• Manage projects from discovery through deployment, ensuring scalability and quality
• Drive engineering best practices and participate in architecture discussions
• Conduct code reviews, mentor engineers, and contribute to technical strategy
• Collaborate with Product, Data, and Commercial teams, translating customer problems into technical solutions
• Build secure, reliable systems, maintaining high engineering standards

Nice to Have

• Experience with NestJS, AI/LLM feature development, or early‑stage start‑up environments
• Knowledge of B2B SaaS, MarTech, or AdTech sectors
• Strong CSS/UI appreciation

Key Responsibilities

• Build & deliver scalable, high‑quality full‑stack features
• Own projects from discovery through deployment
• Participate in architecture discussions and code reviews
• Mentor engineers and foster knowledge sharing
• Collaborate closely with cross‑functional teams to shape product direction
• Enhance platform reliability, security, and performance

Requirements

• Right to work in the UK
• Proficiency in TypeScript, Node.js, and React or Angular
• Experience with AWS, GCP, or Azure
• Hands‑on experience working in high‑growth startups or scale‑ups
• Strong product mindset and ability to make technical/product decisions

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