# Dimitris Hantzis Principal Software Engineer | Engineering Lead | Systems Architect Enterprise Platforms • Architecture & Technical Strategy • Engineering Leadership • Platform Modernisation London, UK [info@dimitrishantzis.com](mailto:info@dimitrishantzis.com) [linkedin.com/in/dchantzis](https://www.linkedin.com/in/dchantzis/) ## About Principal Software Engineer and Systems Architect with 20 years of experience architecting, delivering and evolving enterprise-scale platforms across e-commerce, logistics, fulfilment, inventory and financial domains, combining hands-on architecture and delivery with senior technical and people leadership across business-critical platforms. Specialised in leading the modernisation and architectural transformation of complex, business-critical platforms under live operational constraints, balancing technical change, operational continuity and long-term maintainability. Proven track record of owning cross-system architecture, building resilient operational platforms, and resolving high-impact business risks through pragmatic, observable, and scalable engineering. Highly experienced in reducing system complexity, lowering operational overhead and delivering practical solutions that create immediate business value while remaining resilient, maintainable and scalable. Operates at the intersection of engineering, operations and business, combining technical and people leadership with close collaboration across engineering teams and senior stakeholders in operational and commercial functions to translate complex business needs into pragmatic, reliable and scalable technical solutions. Experience spans systems architecture, enterprise integration, platform modernisation, high-volume transactional systems, operational resilience and technical strategy, with particular emphasis on systems where reliability, data integrity and operational continuity have direct business and financial consequences. Incorporates AI-assisted software engineering where it adds value, helping accelerate solution design, improve engineering productivity and enhance software quality while maintaining strong engineering fundamentals, sound architectural judgement and human ownership of review and production decisions. --- ## Key Impact ### Platform Ownership - Architected, delivered and evolved the central Order Management System (OMS) and integration architecture, with the OMS acting as the operational coordination layer across inventory, purchasing, fulfilment, warehouse, storefronts and financial systems. ### Transformation - Led architectural transformation and modernisation of legacy systems and business-critical workflows. - Rebuilt and repurposed the core Warehouse Management System (WMS) from PHP 5.6 to PHP 8.4. ### Engineering Leadership - Provided cross-team technical and people leadership across business-critical platform initiatives, aligning engineers and Tech Leads around architecture, technical decisions and delivery while line-managing and mentoring engineers. ### Operational - Prevented critical operational and financial risks across business-critical workflows. - Designed and delivered resilient operational infrastructure incorporating queue orchestration, automated recovery, observability, auditability, and fault-tolerant workflow execution across critical business systems. ### Technical - Optimised legacy data models and system-level algorithms, significantly improving performance, efficiency, and scalability across high-volume transactional systems. - Architected scalable integration architecture enabling reliable synchronisation and data interchange across storefront, warehouse, ERP, and financial platforms. ### Engineering Standards & AI - Established structured AI-assisted engineering practices across multiple enterprise codebases, creating system-specific engineering blueprints, architectural context, implementation frameworks and review guardrails. --- ## Professional Experience ### May 2023 - Jun 2026 Senior Lead Software Engineer (Principal Engineer scope) BrandAlley - London, UK - Systems Architecture, OMS & API Integrations: Served as the principal technical authority across interconnected business systems. Conceived, architected, delivered and evolved the central Order Management System (OMS) and its API as the coordination layer across storefronts, inventory, purchasing, fulfilment, warehouse and financial systems. Owned the integration architecture connecting these systems to the OMS, enabling reliable cross-platform workflow orchestration and data interchange, with an architecture designed to support multiple WMSs and evolving fulfilment operations. - Engineering Leadership: Provided technical and people leadership across engineering teams, including direct line management and mentoring of engineers, while providing technical direction and collaborating with four Tech Leads across business-critical platform initiatives. - Senior Stakeholder Partnership: Worked directly with directors and heads of Operations, Finance, Fulfilment, Logistics and Customer Service, leading requirements discovery, shaping technical initiatives and maintaining accountability through production delivery. - Platform Modernisation: Led the architectural transformation of legacy systems into a modular, scalable platform architecture, enabling continuous modernisation while maintaining uninterrupted live operations. - WMS Modernisation: Rebuilt and modernised the core Warehouse Management System (WMS) from PHP 5.6 to PHP 8.4, repurposing core functionality to support BrandAlley’s evolving business requirements while significantly improving performance and maintainability and reducing technical debt. - Operational Resilience: Designed and delivered resilient operational infrastructure incorporating queue orchestration, automated recovery, observability, auditability and fault-tolerant workflow execution across critical business systems. - Cross-System Reliability: Improved reliability and consistency of cross-system data flows, enabling accurate inventory management, order lifecycle orchestration and operational visibility across business-critical platforms. - Supply Chain & Fulfilment Workflows: Architected and evolved operational workflows spanning Purchase Quotations, Purchase Orders, Goods Receipt POs (GRPOs), consignment and virtual stock management, cross-docking, automatic detection of orphan orders and operational workflows to manage them, replacements, returns and cancellations, integrating purchasing, inventory, warehouse, fulfilment and financial operations. - Measurable Impact: Delivered warehouse operational tooling contributing to productivity improvements of approximately 35–55% across fulfilment operations; identified and resolved critical risks including inventory overselling, order duplication and cross-system data inconsistencies, preventing fulfilment failures and financial loss. - Peak Trading Readiness: Led annual technical and operational readiness for peak trading in partnership with Operations, Fulfilment and Customer Experience. Ahead of increased inbound purchasing volumes from September to October, delivered WMS improvements supporting goods receipt, allocation, put-away and stock management; ahead of increased sales volumes from November to January, improved tooling for locating, picking and packing orders. Proactively optimised critical workflows and algorithms, removed obsolete data, reviewed database indexes and high-frequency queries, and delivered a complete redesign and rebuild of the mobile WMS to improve warehouse throughput and operational efficiency during peak periods. - Engineering Standards & AI: Led the introduction of structured AI-assisted engineering practices across multiple enterprise codebases, creating codebase-specific engineering blueprints, architectural context, implementation frameworks and review guardrails. Enabled engineers to use AI more consistently while retaining human ownership of architecture, review and production changes. ### Oct 2021 - Apr 2023 Lead Software Engineer Internet Fusion Group - London, UK - Logistics Platform Leadership: Led a cross-functional team of 7 across engineering, QA and product responsible for the delivery and evolution of bespoke warehouse logistics platforms supporting order management, inventory and financial workflows. - Backend & Domain Expertise: Led the technical design and delivery of backend platform capabilities supporting order management, inventory control, reconciliation, reporting and financial transaction workflows. - Platform Architecture: Worked across a core monolithic WMS alongside separate Laravel services, including a supplier-feed service integrating with external systems to retrieve, analyse and normalise supplier stock files for downstream purchasing workflows, and a separate payment service. - High-Volume Transactional Systems: Improved platform performance, reliability and scalability by optimising database architecture and resolving critical concurrency issues such as deadlocks across high-volume transactional systems. - Cross-Team Technical Ownership: Acted as technical owner of the central WMS while multiple engineering teams delivered concurrent changes across the platform, coordinating technical dependencies, overlapping development and releases across team boundaries to maintain platform stability. - Platform Modernisation: Modernised legacy platforms through systematic refactoring and architectural improvements, improving maintainability, reducing technical debt and increasing long-term system stability. - Engineering & Delivery Standards: Established structured engineering and delivery practices across planning, estimation, development, testing, release and deployment activities, improving delivery predictability, system reliability and team effectiveness. ### Feb 2020 - Oct 2021 Lead Software Engineer 3ev (3rd Eye Vision) - Hove, UK - Client Discovery & Solution Definition: Worked directly with clients to discover requirements, define technical solutions, communicate risks and trade-offs, prepare estimates and delivery plans, and maintain alignment through implementation and production release. - Backend Platform Delivery: Led the technical design and delivery of backend platform capabilities for multiple client systems, supporting core business workflows and third-party integrations. - Distributed Platform Architecture: Worked across a platform comprising a legacy TYPO3 monolith alongside separate legacy Laravel applications and API services supporting booking and integration capabilities, including an API exposing booking, property and availability data to approximately 50–60 external systems. Designed and developed a new bidirectional integration service consuming and exposing third-party APIs. - Platform Modernisation: Modernised legacy platforms by upgrading from Laravel 4.2 (PHP 5.6) to Laravel 8 (PHP 8.0) and introducing SOLID design principles, improving maintainability, scalability and long-term platform sustainability. - Observability & Reconciliation: Designed and implemented logging, auditing and notification capabilities, improving observability, traceability and supporting reconciliation workflows across client platforms. - End-to-End Technical Ownership: Led implementation and production delivery across multiple client platforms, coordinating technical decisions and resolving issues through release. - Cloud & Development Infrastructure: Modernised infrastructure and deployment workflows by migrating systems from AWS to Google Cloud, reducing infrastructure costs and establishing Docker-based local development environments. ### Nov 2016 - Dec 2019 Senior Software Engineer Tillo - Hove, UK - Financial Transaction Platform & APIs: Worked on a financial transaction platform integrating multiple gift-card and stored-value systems behind a unified, secure API. Redesigned and evolved the API and partner integrations supporting creation and bulk creation, cancellations, refunds and balance management across fixed and variable-denomination gift codes. - Secure Transaction Workflows: Developed secure transaction and integration workflows, ensuring adherence to industry-standard security practices. - Reconciliation & Transaction Integrity: Implemented reconciliation workflows and validation mechanisms, ensuring accuracy and integrity of financial transactions across partner integrations. - Partner & Enterprise Integrations: Delivered integrations with third-party systems, including SAP, supporting partner onboarding and enabling reliable data exchange across platforms. - Platform Evolution: Contributed to the evolution of the platform from early-stage product to stable production system, supporting increasing transaction volumes and expanding partner integrations. ### Jun 2016 - Nov 2016 Senior Software Engineer 22PointSix - Burgess Hill, UK - Backend APIs: Developed backend services and REST APIs supporting bespoke web applications and client platforms. - Application Development: Built new backend functionality using PHP and Symfony while maintaining existing production systems. - Infrastructure: Configured and maintained server and database environments across cloud-hosted infrastructure. - Production Support: Resolved production issues and delivered ongoing platform improvements through client maintenance engagements. - Technical Documentation: Produced technical documentation supporting development, deployment, and operational processes. ### Jan 2013 - Dec 2015 Senior Full-Stack Web Developer Mosaic Digital - Brighton, UK - Application Development: Developed and maintained bespoke web applications and CMS platforms for clients across multiple industries. - Reusable Architecture: Designed reusable backend modules and shared components, improving development efficiency and long-term maintainability. - Project Delivery: Planned and delivered new project functionality while maintaining a large portfolio of existing client systems. - Infrastructure & Release: Managed server, database, testing, deployment, and release activities across multiple concurrent client projects. - CMS Development: Part of the core agency team that produced the new agency CMS based on Drupal 7. ### Jul 2012 - Jan 2013 Freelance Software Engineer Thessaloniki, Greece - Designed and developed bespoke websites and web applications for small businesses and independent clients. - Delivered end-to-end solutions including backend development, database design, frontend implementation, and deployment. ### Jul 2009 - Jun 2012 Full-Stack Software Engineer Tera Media - London, UK & Athens, Greece - Designed and developed backend and frontend functionality for bespoke web applications and custom content management systems. - Contributed to the development of in-house digital publishing platforms supporting journalism, video, and photo gallery workflows. ### Oct 2006 - Jul 2009 Freelance Software Engineer Thessaloniki, Greece - Delivered freelance software development projects for local businesses and independent clients alongside university studies and part-time employment, designing and developing bespoke web applications from concept through deployment. ### Apr 2006 - Oct 2006 Software Engineer (BSc Internship) Alexander Technological Educational Institute, Greece - Completed a six-month BSc software engineering internship, designing and developing a full-stack web application for the Department of Informatics that streamlined academic application management for university faculty. ### Mar 2004 - Apr 2006 Freelance Software Engineer Thessaloniki, Greece - Delivered freelance software development projects for local businesses and independent clients, designing and developing bespoke web applications from concept through deployment. --- ## Military Service ### Sept 2011 - Jul 2012 Second Lieutenant (Reserve) - Head of the Research and Informatics Office 88 Military Command, Hellenic Army - Lemnos, Greece Served as Head of the Research and Informatics Office at 88 Military Command on the island of Lemnos. Led a team responsible for maintaining IT infrastructure across multiple military units and served as Brigade Communications Officer on a rotating basis. --- ## Technical Expertise ### Architecture & Systems Distributed systems, modular and monolithic architectures, system design Synchronous/asynchronous integrations, REST APIs, queue-based processing, event-driven architecture Resilient operational infrastructure, queue orchestration, resilience patterns, fallback mechanisms ### Domain & Platforms WMS, OMS, fulfilment, inventory, logistics, financial systems, payment processing ERP (Business Central, SAP), e-commerce platforms (Magento), third-party API integrations ### Engineering Leadership Technical leadership, people leadership and mentoring, engineering standards Architectural decision-making and facilitation, cross-functional stakeholder alignment Modernisation under live operational constraints, incremental delivery ### Backend & Web PHP (4 - 8.4), Laravel (4.2 - 13), Symfony, Lumen, Zend JavaScript, TypeScript, AJAX, jQuery, Alpine.js, Filament, HTML5, CSS3, Jekyll, Liquid Current development and learning: Python, FastAPI, SQLAlchemy, Alembic, Django, React.js, Node.js, Kafka, GraphQL ### Data & Storage Databases: MySQL, PostgreSQL, SQLite Caching & In-memory Data: Redis, Memcached High-volume transactional systems, data modelling, performance optimisation ### Infrastructure & DevOps AWS, Google Cloud (GCP), DigitalOcean, Docker, Kubernetes, Linux, Bash CI/CD, deployment workflows, system observability ### Engineering Practices Non-functional requirements: reliability & availability, performance & scalability, resilience & recoverability, data integrity & consistency Observability, auditability & traceability Code quality, testing strategies, secure development practices ### AI-Assisted Engineering AI-assisted software engineering, LLM-assisted architecture and implementation System-specific engineering standards, architectural documentation and structured development workflows Claude, Codex, ChatGPT --- ## Education - **MSc Design and Digital Media** University of Edinburgh, UK - **BSc Informatics Engineering (Computer Science)** Alexander Technological Educational Institute of Thessaloniki, Greece - **Reserve Infantry Officers Academy** Signal Corps & Research and Informatics Corps Hellenic Armed Forces, Greece --- ## Professional Development Attended industry conferences including Laravel London, AWS London, and UX Brighton. --- ## Languages - English (Fluent) - Greek (Native) --- [Download Detailed CV (PDF)](https://dimitrishantzis.com/docs/Dimitrios_Chantzis_CV.pdf) [View Detailed CV (Markdown)](https://dimitrishantzis.com/markdown)