Kristof Ringleff
I design and deliver systems where technical architecture meets commercial reality.
Over 15+ years, I have shipped production software used by merchants in 160+ countries, led end-to-end AWS solution design, and delivered complex migrations from legacy systems to modern platforms. I stay with the work beyond architecture - through to production and ongoing operation.
My work spans serverless architecture, e-commerce platforms, API integration, and legacy transformation, with a consistent focus on reducing infrastructure costs and improving reliability.
Core Competencies
Cloud & Infrastructure
Languages & Frameworks
E-commerce & Platforms
Architecture & Delivery
Ways of Working
How I Help
I translate business goals into technical designs that hold up in production - and stay close to delivery to make sure the solution lands.
Solution & Platform Architecture
I design cloud-native and hybrid systems that work today and don't fall over when the platform upgrades next quarter. I've been through enough major version changes to know what upgrade-safe, scalable architecture looks like in practice - and what it costs when you skip it.
Legacy Modernisation & Digital Transformation
Most systems don't need a full rebuild. I help organisations work out what to keep, what to replace, and how to migrate safely without breaking what's already running. The goal is less complexity, better maintainability, and lower long-term cost - not more technology for its own sake.
Integration & API Design
I design integration architectures that connect platforms, services, and third-party systems reliably. This includes API design, event-driven messaging, authentication flows (OAuth 2.0, token management), and making sure data moves between systems without silent failures.
Technical Strategy
I help make architecture decisions when there's no obvious right answer - working out what to build, what to buy, and what's realistic given the constraints. I've spent 15+ years making these calls for my own business, which means I'm used to weighing the technical trade-offs against the commercial ones - not just drawing the architecture but seeing how it plays out in practice.
AI Introduction
I help teams work out where AI genuinely adds value and where it's just adding complexity. The focus is on practical implementation with clear outcomes and using tokens efficiently.
What Clients Say
I contacted Kristof as we needed a way to charge a fee on orders depending on payment method. He understood the problem immediately and provided a clean solution that worked perfectly for our setup.
Ellen, Director, international retailer
We are using Kristof's software for quite a few years now. They work reliably and the quality is consistently high.
Sebastian, Director Architecture & Strategy, digital commerce agency
I will definitely recommend your software to our subsidiaries, I've never seen such a perfectly coded extension and excellent support.
Eduard, Full-Stack Developer, German consortium
Proven Track Record
Solution Architect & Director - Fooman
I founded and led a product-focused software company building solutions for e-commerce merchants worldwide. Over that time I led multiple rounds of digital transformation on our own platform - re-architecting for serverless, migrating legacy systems, and replacing core infrastructure - while keeping everything running for existing customers. With a small team, I owned everything from solution design and technical strategy through to production delivery and support, which meant the problems I saw in production directly shaped the architecture decisions I made next.
Solution Architecture & Technical Strategy: Designed and evolved a portfolio of 18+ production software products deployed world-wide and used by enterprise brands including Nespresso and Panasonic. Led all architecture decisions - prioritising scalability, upgrade safety, and long-term maintainability to minimise technical debt for end-users.
Cloud Architecture & Serverless Delivery (AWS): Designed and delivered a serverless, event-driven SaaS platform on Amazon Web Services - Lambda, DynamoDB, API Gateway, CloudFront, KMS - achieving ~89% reduction in monthly infrastructure cost and horizontal scalability with zero capacity planning. Beyond this project, I've worked across a broad range of AWS services including ECS/Fargate, EFS, Aurora Serverless, EventBridge, and SSM Parameter Store - with a focus on understanding the cost model and operational trade-offs of each service rather than defaulting to the most familiar option.
Platform Modernisation & Migration: Led the migration of a 15-year legacy e-commerce platform including domain migration, subscription billing replacement, and frontend modernisation (React, GraphQL). Delivered with zero SEO impact and no revenue disruption.
Platform Integration: Designed and built integration architecture connecting e-commerce platforms with Xero accounting - including OAuth 2.0 authentication flows, encrypted token storage, and secure API communication handling thousands of transactions.
Platform Collaboration & Ecosystem Leadership: Collaborated directly with Magento/Adobe Commerce as a Technology Partner. Recognised as a Magento Master (2016–2018) - 1 of 20 worldwide - for sustained technical leadership and contribution to platform architecture standards.
Technical Team Leadership: Led and mentored a distributed team across development and support. Established engineering standards for code quality, CI/CD pipelines, Docker-based development environments, documentation, and sustainable delivery practices.
Production Reliability & Incident Response: Maintained production systems serving merchants in 160+ countries with sustained 5-star ratings. Built solutions that survived multiple major platform overhauls - when the platform shipped breaking changes, the products kept running.
Earlier Technical & Operational Experience
Before founding Fooman, I worked across technical delivery and operations - managing production for the "Skinit" business unit at Telegistics/Telecom (now Spark), coordinating large-scale merchandising logistics across Telecom's national retail network, delivering 3D compositing and technical animation at q-bus Mediatektur in Germany (including high-profile media installations at CeBIT for Telekom), and freelance web development for clients including the German Institute for International and Security Affairs.
Case Studies
Serverless SaaS Re-Architecture & Compliance Migration
I re-architected our Xero integration platform from the ground up in under 8 weeks. The existing decentralised extension model was no longer viable, we had a mandatory migration to OAuth 2.0, and there was a hard external deadline with zero tolerance for service interruption.
Serverless SaaS Re-Architecture & Compliance Migration
I re-architected our Xero integration platform from the ground up in under 8 weeks. The existing decentralised extension model was no longer viable, we had a mandatory migration to OAuth 2.0, and there was a hard external deadline with zero tolerance for service interruption.
Outcomes
- Full re-architecture delivered in under 8 weeks to fixed external deadline
- ~89% reduction in monthly infrastructure cost
- Horizontal scalability with no capacity planning required
- Achieved Xero Verified App status
- Secure token storage with KMS-backed encryption
Architecture decisions
Designed a centralised, serverless, event-driven architecture on AWS. Stateless compute via Lambda behind API Gateway. High-throughput, low-latency persistence using DynamoDB. OAuth 2.0 flows implemented using managed identity services. Frontend delivery via CloudFront with automated CI/CD using AWS Amplify.
Legacy Platform Modernisation & Subscription Billing Migration
Led the end-to-end solution design for migrating a 15-year legacy e-commerce platform - including domain migration, billing provider replacement, and frontend modernisation - without disrupting active subscriptions or organic search traffic.
Legacy Platform Modernisation & Subscription Billing Migration
Led the end-to-end solution design for migrating a 15-year legacy e-commerce platform - including domain migration, billing provider replacement, and frontend modernisation - without disrupting active subscriptions or organic search traffic.
Outcomes
- Zero loss of organic traffic across 15-year domain history
- Seamless migration of all active subscriptions with no revenue disruption
- Improved frontend performance and long-term maintainability
- Reduced architectural risk through phased migration
Architecture decisions
Designed a phased migration strategy with rollback points at each stage. Comprehensive 301 redirect mapping to preserve search equity. Introduced React-based frontend consuming a GraphQL API layer. Replaced legacy subscription billing provider with no interruption to active recurring revenue.
Platform Ecosystem Architecture & Product Governance
Designed and governed a production software portfolio spanning 18+ products with lifecycles exceeding 10 years - used by enterprise brands including Nespresso and Panasonic and deployed in 160+ countries.
Platform Ecosystem Architecture & Product Governance
Designed and governed a production software portfolio spanning 18+ products with lifecycles exceeding 10 years - used by enterprise brands including Nespresso and Panasonic and deployed in 160+ countries.
Outcomes
- Sustained 5-star average ratings across the portfolio over 10+ years
- Merchants stayed because things kept working - even through multiple major platform overhauls
- Products evolved alongside the platform without breaking what merchants were already running
- Managed deliberate end-of-life and deprecation decisions when products reached the end of their useful lifespan
Architecture decisions
Defined and maintained engineering standards across the entire portfolio - not just for initial development but for ongoing maintenance across 10+ year product lifecycles. Standardised CI/CD pipelines and Docker-based local development environments. Designed plugin-oriented, upgrade-safe architectures that absorbed major platform changes without breaking merchant stores. Managed version compatibility matrices across 18+ products, multiple platform versions, and PHP version requirements simultaneously. Made deliberate backward-compatibility guarantees - and honoured them across years of platform evolution.
International conference speaker (2016–2019) on topics including extensible platform architecture, dependency management, and reliable delivery at scale. Conferences include Magento Imagine (US), Magento Live (UK & AU), and European industry events.
Recognised as a Magento Master (2016–2018) - 1 of only 20 worldwide - reflecting sustained technical leadership, community contribution, and deep expertise in platform architecture and ecosystem standards.
This experience informs my current work as a Solution Architect: designing extensible platforms, guiding organisations through safe modernisation, and building delivery confidence into complex systems.
Industry
Recognition
Why Work With Me
Deep experience, low ramp-up: I can look at a system and have a pretty good idea of what's going on quickly - whether that's tracing a production issue through a stacktrace or diagnosing why a server configuration is silently corrupting file attachments. I don't need long onboarding periods to start contributing.
Practical, not theoretical: I don't build technology for its own sake. Every architecture decision ties back to a business problem. I've shipped production code used worldwide - reliability isn't an aspiration, it's what I've been delivering.
Technical communication: I'm used to being the person who explains what's technically possible to non-technical people and turns business needs into architecture decisions that a development team can build.
Full-lifecycle ownership: I've owned everything from initial solution design through to production support and incident response. That end-to-end perspective means I design systems with operational reality in mind, not just what looks good on a diagram.
Proven across the full stack: I've designed serverless platforms on AWS, migrated legacy systems without downtime, built third-party integrations from authentication through to data sync, and maintained a production software portfolio for over a decade.
Available for Permanent & Contract Roles
I'm currently available for permanent and contract roles - the kind of work where having designed, built, and operated production systems for 15+ years makes a real difference.
Whether it's cloud architecture, platform modernisation, enterprise integration, or helping your team make better technical decisions. Happy to have a chat about how I can help.