Senior Backend Developer; PHP​/AI

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.

• 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.

• 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.

• 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.