Senior Backend Developer (PHP / AI)

SeekMe; Greater London; Hybrid; GBP 70,000 - 110,000; Full time

Job summary

Multis UK Limited is seeking a Senior Backend Developer to lead the architecture, development, and enhancement of production systems and online marketplaces. The role offers flexible formats and a fully remote setup, with a focus on AI-assisted software engineering.

You will design backend architectures, implement REST APIs, and mentor junior developers while integrating AI tooling and external services to accelerate delivery.

Qualifications

• Extensive backend engineering experience with architectural ownership.
• Proficient in PHP 8+ and SQL databases.
• Strong REST API design and maintenance experience.
• Familiar with AI tooling and AI agents for development.
• Experience with microservices and cloud deployment.
• Knowledge of search infrastructure (Elasticsearch, etc.).

Responsibilities

• Design and build backend applications and REST APIs.
• Manage search technologies, automation pipelines, and third‑party integrations.
• Lead code reviews, debugging, automated testing, and mentorship.
• Integrate AI tooling and AI APIs into applications where relevant.

Skills

Backend architecture

API design

Mentorship

AI tooling

Microservices

Cloud deployment

Tools

PHP 8+

SQL

REST APIs

Git

Linux

Docker

Elasticsearch

Job description

Role Overview

Multis UK Limited is hiring an experienced Senior Backend Developer to lead the architecture, development, and enhancement of production systems, REST APIs, and online marketplace platforms. The position features flexible work formats (part-time, full-time, or contract) in a fully remote environment, with a strong focus on AI-assisted software engineering.

Key Responsibilities

• Backend & API Architecture: Design and build backend applications and REST APIs using PHP 8+ and SQL databases while refining existing production systems.
• Integrations & Automation: Manage search engine technologies, automation pipelines, and third‑party service integrations.
• Quality & Mentorship: Conduct code reviews, debugging, automated testing, and provide technical mentorship to junior developers.
• AI Tooling & Integration: Leverage AI coding assistants and agents for development, research, testing, and code review, and embed AI/LLM APIs into applications where relevant.

Key Requirements

• Experience Level: Strong commercial experience in backend engineering with proven independence in making architectural decisions.
• Core Technical Stack: Advanced proficiency in PHP 8+, SQL, REST API design/maintenance, Git, Linux, and Docker.
• Software Practices: Deep understanding of existing codebases, modern development workflows, and hands‑on comfort with AI coding tools and AI agents.
• Databases & Search: Experience with MySQL, PostgreSQL, Elasticsearch, or search infrastructure.
• Architecture & Cloud: Microservices, asynchronous processing, and cloud deployment (e.g., Microsoft Azure).
• Advanced AI: Direct experience integrating LLM/AI APIs, agents, or AI‑assisted content processing.

What We Offer

• Direct involvement with international production platforms and marketplaces.
• Exposure to modern workflows centered around AI‑assisted engineering.
• High level of technical autonomy with the ability to shape overall architecture and technical direction.