Founding Full-Stack Engineer — AI-Powered Marketplace

Sigma Consulting Group; Greater London; Hybrid; GBP 45,000 - 55,000; Full time

Benefits offered by this job

Equity participation

High level of autonomy

Job summary

Sigma Consulting Group is looking for a Full-Stack Developer (Founding Engineer) based in London. This hybrid role is integral to the development of an AI-powered marketplace for healthcare procurement. Responsibilities include building a WordPress-based platform, integrating AI capabilities, and ensuring system performance and compliance. Candidates should have at least 3 years of full-stack development experience, particularly in PHP and JavaScript frameworks like React. The role offers competitive compensation, equity participation, and opportunities for technical leadership.

Qualifications

• Minimum of 3+ years' experience in full-stack development.
• Strong proficiency in PHP with hands-on WordPress/WooCommerce development experience.
• Solid frontend development skills using JavaScript and frameworks such as React.

Responsibilities

• Develop, customise, and enhance a WordPress/WooCommerce-based marketplace platform.
• Build core features such as quote request systems and supplier matching.
• Design and implement scalable backend services supporting marketplace operations.

Skills

Full-Stack Development

PHP

WordPress/WooCommerce

JavaScript

React

RESTful API

Database Design

Secure Coding

Tools

Docker

AWS

Stripe

PayPal

Job description

Full-Stack Developer (Founding Engineer)

About the job Full-Stack Developer (Founding Engineer)

Full-Stack Developer (Founding Engineer)

Location: London, United Kingdom (Hybrid)
Employment Type: Full-Time
Department: Engineering
Compensation: £50,000 + Equity

About Zenrox

Zenrox Healthcare UK is building an AI-powered marketplace that connects healthcare providers with MHRA-compliant medical equipment suppliers. Our flagship platform, ZenroxIQ, transforms procurement through intelligent supplier matching, automated compliance workflows, and predictive analytics—serving NHS trusts and private healthcare organisations across the UK.

The Opportunity

We are seeking a talented Full-Stack Developer to join as a Founding Engineer, playing a key role in designing, building, and scaling our marketplace platform.

This is a hands-on role offering end-to-end ownership across the technology stack—from crafting seamless user experiences to developing robust backend systems. You will work closely with the CTO to shape architecture, implement core features, and deliver a high-performance platform that drives efficiency in healthcare procurement.

Key Responsibilities

Platform Development

Develop, customise, and enhance a WordPress/WooCommerce-based marketplace platform

Build core features such as quote request systems, supplier matching, and order workflow management

Design and implement scalable backend services supporting marketplace operations

Frontend & User Experience

Optimise user experience across buyer and supplier journeys

Integrate AI-driven capabilities such as visual search and pricing optimisation into the platform

Collaborate on the implementation of intelligent features that enhance procurement decision-making

API & System Integration

Design, develop, and maintain RESTful APIs

Integrate third-party services including payment gateways, compliance verification systems, and analytics tools

Implement secure payment processing and escrow functionalities

Performance, Security & Compliance

Optimise platform performance, scalability, and reliability

Apply secure coding practices and ensure compliance with GDPR and data protection standards

Maintain high availability and system integrity

Collaboration & Technical Strategy

Work closely with the CTO on architecture, technical design, and system scalability

Contribute to technical decision-making, documentation, and engineering best practices

Participate in agile development processes and continuous improvement initiatives

Requirements

Minimum of 3+ years' experience in full-stack development

Strong proficiency in PHP with hands-on WordPress/WooCommerce development experience

Experience with database design and optimisation (MySQL or PostgreSQL)

Strong understanding of RESTful API design and integration

Knowledge of secure coding practices and data protection (GDPR)

Ability to work independently, take ownership, and make pragmatic technical decisions

Preferred / Advantageous Experience

Experience building marketplace or e-commerce platforms

Hands-on experience with payment gateway integrations (e.g., Stripe, PayPal)

Experience developing B2B or enterprise-grade software solutions

Familiarity with WooCommerce plugins (e.g., YITH or similar tools)

Exposure to healthcare or regulated industries

Why Join Zenrox

Founding engineering role with meaningful ownership and equity participation

Opportunity to build critical infrastructure for healthcare procurement

High level of autonomy to design and implement end-to-end solutions

Direct collaboration with a visionary founding team

Clear pathway to technical leadership roles as the company scales

How to Apply

Interested candidates should submit their:

CV

Link to a relevant project (or a brief project description)