# Project dossier: Martin Trenker - Document language: en (English) - Document format: UTF-8 Markdown ## Profile - Role titles: Technical Lead; Solutions Architect - Availability: Available - Location and work model: Munich and remote DACH - Languages: German and English - Utilization: 2–5 days/week - Project types: Architecture modernisation; delivery reliability; governed AI workflows ## Summary What drives me is improving digital systems and products for the people who work with and use them. I get to the bottom of a problem and solve it where it belongs. At Douglas that took me from React Expert on the POS software to Solutions Architect for the CRM backend, where I designed one unified API so business logic no longer had to be duplicated across several frontends. My experience goes back to renting my first server as a teenager. From 2006 to 2008 I was employed as a developer in two positions; since 2008 I have been self-employed, with client projects ranging from PHP and Oracle systems to React frontends and .NET APIs. My own products run on a Kubernetes platform I operate myself. - Douglas · client work: One API instead of duplicated logic. Designed a unified CRM API (REST + GraphQL), ending business logic duplicated across multiple frontends - Douglas · client work: An in-house service instead of SaaS. Built an in-house shortlink and QR service in Next.js + .NET in weeks, from request to production, replacing a third-party SaaS that no longer met business needs - Own systems · self-funded: A production platform I run myself. I provision the cluster and own deployment, observability, data services, secrets, upgrades, and recovery. ## Core skills - dotnet - csharp - graphql - rest - typescript - node.js - nestjs - express - react - next.js - aws (2020–2025) - aws-cdk - lambda - dynamodb ## Recent projects ### 1. Douglas GmbH - Role titles: React Expert → Technical Lead → Solutions Architect - Period: Jan 2024 – Jul 2026 - Location and work model: Düsseldorf - Sector: Retail #### Mandate Modernise the POS/CRM platform from its React frontend to backend services in TypeScript/Node.js and C#/.NET, unify the CRM API landscape, and introduce governed AI tooling. #### Why a separate C#/.NET API Extending the existing NestJS/TypeScript API was one of a few options. Internally, though, there was a move towards C# on the backend, because it was the best understood and supported setup. The existing API was also not built from the ground up for the resilience and scaling the unified API required; adding another controller to it would have meant shoehorning those requirements in. I continued to maintain the production TypeScript API. #### Personal ownership - extended the solution into C#/.NET and personally designed and shipped the unified API, applying architecture patterns across stacks and using AI tooling as part of a reviewable engineering workflow - replaced static code-level tenant configuration with dynamic runtime config served by the API — config changes no longer require a release - developed and maintained a production CRM backend in TypeScript/Node.js with NestJS and Express, covering API endpoints, configuration, and external service integrations - built a Node.js/TypeScript agent CLI giving AI agents governed access to Jira, Confluence, Azure DevOps, and internal tooling, with human review of all output #### Outcomes and evidence - Measured fact: software runs on every cash register in more than 1,200 stores across 14 European countries - Measured fact: rewrote the CRM/POS integration in under a year with clearer architecture, more test coverage, and updated documentation - Unmeasured observation: moved from after-hours deployment windows toward safer deployments during business hours through better error handling, observability, and recovery paths - Unmeasured observation: built an in-house shortlink and QR service in Next.js + .NET in weeks, from request to production, replacing a third-party SaaS that no longer met business needs #### Team delivery and contribution - onboarded 1 senior and 2 junior developers; all productive contributors within weeks - introduced "Full Stack Fridays", team-driven learning sessions covering Figma prototyping, GraphQL, C#/.NET, and more - Technologies: react; typescript; node.js; nestjs; express; angular; next.js; dotnet; csharp; mongodb; kubernetes; azure-devops; instana; grafana; graphql; rest; entra-id; oauth ### 2. Oetker Digital GmbH - Role titles: Solutions Architect - Period: Sept 2022 – May 2023 - Location and work model: Berlin - Sector: #### Situation A Next.js platform was moving from an external agency to a newly formed in-house team while active delivery continued. #### Mandate Audit the codebase, consolidate two products, and establish the new team without stopping ongoing product work. #### Personal ownership - audited the codebase and improved quality across the stack: Next.js, TypeScript, GraphQL, Apollo, Cypress, Storybook, Tailwind - consolidated two separate web products into a single codebase without disrupting active development #### Outcomes and evidence - Unmeasured observation: consolidated two separate web products into a single codebase without disrupting active development #### Team delivery and contribution - onboarded four new hires in parallel while keeping delivery on track - introduced lightweight agile practices that the team adopted - Technologies: react; next.js; typescript; graphql; apollo; cypress; storybook; tailwindcss ### 3. Fielmann AG - Role titles: Technical Architect - Period: Mar 2021 – Dec 2021 - Location and work model: Munich - Sector: Retail #### Situation An AngularJS optometry workflow for in-store staff had accumulated complex, ad-hoc state logic. #### Mandate Rebuild the workflow in TypeScript and React with an explicit state-machine architecture and transfer the knowledge into the team. #### Personal ownership - state-machine driven multi-step form architecture built to make changes safer - custom on-screen keyboards tailored to in-store workflows #### Outcomes and evidence - Unmeasured observation: state-machine driven multi-step form architecture built to make changes safer #### Team delivery and contribution - daily pair-programming as the main knowledge transfer strategy - Technologies: react; typescript; xstate; storybook; cypress ## Sectors - Automotive - Consulting - Engineering - Finance - Gaming - Machine Manufacturing - Media - Retail - Travel ## Contact - info@clean.dev: mailto:info@clean.dev - clean.dev: https://clean.dev - xing.com/profile/Martin_Trenker2: https://www.xing.com/profile/Martin_Trenker2 - linkedin.com/in/martin-trenker-193449291: https://www.linkedin.com/in/martin-trenker-193449291/ - github.com/mtrenker: https://github.com/mtrenker ## Full project history ### Douglas GmbH - Period: Jan 2024 – Jul 2026 - Role titles: React Expert → Technical Lead → Solutions Architect - Context: Düsseldorf; Retail Modernise the POS/CRM platform from its React frontend to backend services in TypeScript/Node.js and C#/.NET, unify the CRM API landscape, and introduce governed AI tooling. - Technologies: react; typescript; node.js; nestjs; express; angular; next.js; dotnet; csharp; mongodb; kubernetes; azure-devops; instana; grafana; graphql; rest; entra-id; oauth ### Oetker Digital GmbH - Period: 2022 – 2023 - Role titles: Solutions Architect - Context: Berlin Managed the handover of a Next.js platform from an external agency to a newly formed in-house team, audited the codebase, merged two products, and got the team up to speed. - audited the codebase and improved quality across the stack: Next.js, TypeScript, GraphQL, Apollo, Cypress, Storybook, Tailwind - consolidated two separate web products into a single codebase without disrupting active development - onboarded four new hires in parallel while keeping delivery on track - introduced lightweight agile practices that the team adopted - Technologies: react; next.js; typescript; graphql; apollo; cypress; storybook; tailwindcss ### UXMA GmbH & Co. KG - Period: 2022 - Role titles: Technical Lead - Context: Munich Led a three-person team building a data-heavy internal web app in TypeScript and React, with a strong focus on mentoring two junior developers. - daily pair-programming with two juniors, both grew into independent contributors within weeks - tracked down and resolved chronic render-cycle bottlenecks, reducing page interaction delays - Technologies: react; typescript; redux-toolkit; jest; react-testing-library; storybook; cypress ### Fielmann AG - Period: 2021 - Role titles: Technical Architect - Context: Munich; Retail Rewrote a complex AngularJS optometry workflow app in TypeScript/React, replacing ad-hoc state logic with XState-driven form architecture for in-store staff. - daily pair-programming as the main knowledge transfer strategy - state-machine driven multi-step form architecture built to make changes safer - custom on-screen keyboards tailored to in-store workflows - Technologies: react; typescript; xstate; storybook; cypress ### Interhyp AG - Period: 2020 – 2021 - Role titles: Engineering Consultant - Context: Munich; Finance Built a real-time communication micro-frontend handling VoIP calls between customers and mortgage advisors, using React, Redux Toolkit and WebRTC. - took on agile coaching alongside development, reducing sprint friction - first production WebRTC integration, shipped without third-party SDK - Technologies: react; redux-toolkit; webrtc; jest; storybook; react testing library ### ProSiebenSat.1 Digital GmbH - Period: 2019 - Role titles: Frontend Engineer - Context: Munich; Media Built and maintained React components powering high-traffic show websites for ProSieben and Sat.1 formats, with GraphQL APIs and analytics tracking throughout. - Technologies: react; graphql; jest; cypress; storybook; apollo ### InstaMotion Retail GmbH - Period: 2019 - Role titles: Frontend Engineer - Context: Munich; Retail Built a React + GraphQL web magazine for Germany's largest online car dealer, connected to a headless CMS. - Technologies: react; headless-cms; storybook; jest ### Fineway AG - Period: 2018 - Role titles: Frontend Engineer - Context: Munich; Travel Built components for an online travel magazine using React, TypeScript and GraphQL, backed by Contentful as a headless CMS. - Technologies: typescript; react; graphql; headless-cms; storybook; jest ### Lufthansa AG - Period: 2017 – 2018 - Role titles: Frontend Engineer - Context: Hamburg Developed React components for Lufthansa's digital touchpoints, integrated into Adobe Experience Manager. - accessibility as a hard requirement, not an afterthought - component library built for editorial reuse across markets - Technologies: react; aem; typescript; redux; storybook; jest ### Brückner Group - Period: 2016 – 2017 - Role titles: Real-time Web Systems Engineer - Context: Siegsdorf; Machine Manufacturing Built real-time monitoring dashboards served directly on industrial machines, using native web components years before they went mainstream. - early adopter of native web components via Polymer in a production manufacturing context - Technologies: polymer; web-components ### F24 AG - Period: 2016 - Role titles: Lead Developer - Context: Munich Ported an iOS app to Android using React and Cordova. Scoped, executed and shipped within two months. - Technologies: react; cordova ### Mindogo GmbH - Period: 2016 - Role titles: Technical Lead - Context: Munich; Consulting Delivered a QR-code-based badge management system for staff and visitors, including on-demand print integration. - Technologies: laravel; angularjs; mysql; javascript; html; css; php; printing; qr-codes ### McKinsey & Company - Period: 2014 – 2016 - Role titles: Technical Lead - Context: Munich; Consulting Rearchitected a legacy migration tool, moved to Symfony + React with CQRS-backed data structures, and made changes easier to trace and review. - introduced CQRS in a PHP project at a time when the pattern was still uncommon there - Technologies: symfony; react; cqrs; mysql; javascript; html; css; php ### BMW Group - Period: 2013 - Role titles: Fullstack Developer - Context: Munich; Automotive Built a multi-region dealer evaluation platform for BMW, supporting both customer-facing and internal staff surveys across global markets. - hierarchical evaluation model: store → local → regional → country, each level saw exactly the data their role required - adopted AngularJS before the framework was mainstream in enterprise contexts - multi-region, multi-language rollout across BMW's global dealer network - Technologies: laravel; angularjs; mysql; javascript; html; css; php ### McKinsey & Company - Period: 2012 – 2014 - Role titles: Fullstack Developer - Context: Munich; Consulting Maintained a worldwide hardware migration tracking system used across McKinsey offices globally, built on Zend Framework and Oracle DB. - Technologies: zend-framework; oracle; javascript; html; css; php ### Mindogo GmbH - Period: 2012 – 2016 - Role titles: Fullstack Developer - Context: Munich; Consulting Owned a full-stack auction platform used for a company-wide annual charity event, covering database schema, backend, and frontend. - Technologies: laravel; angularjs; mysql; javascript; html; css; php ### Travian Games - Period: 2010 – 2011 - Role titles: Frontend Developer - Context: Munich; Gaming Built interactive JS components for a live browser game, with a tight focus on performance and smooth real-time UX. - Technologies: mootools; javascript; html; css ### McKinsey & Company - Period: 2009 – 2012 - Role titles: Fullstack Developer - Context: Munich; Consulting Extended and maintained a global asset management system for McKinsey's IT operations, built on PHP, ExtJS and Oracle DB within a cross-functional agile team. - Technologies: extjs; oracle; php; javascript; html; css; zend-framework ### Siemens AG - Period: 2008 – 2009 - Role titles: Web Developer - Context: Munich; Engineering Built and maintained internal web portals for one of Germany's largest engineering firms within a SharePoint environment. - Technologies: sharepoint; javascript; html; css; google-maps ## Current hands-on systems ### EU-sovereign Kubernetes platform - Period: since 2025 After five years of running my own projects serverless on AWS (CDK, Lambda, Cognito), I migrated everything in 2025 to a self-operated Kubernetes platform on European infrastructure — and have run it in production since. - Personal ownership: I provision the cluster and own deployment, observability, data services, secrets, upgrades, and recovery. - Client relevance: Direct operating experience with GitOps, Kubernetes, and production observability informs architecture and delivery decisions for client systems. - Operational responsibility: Five production applications run on the platform with PostgreSQL pooling, alerts, dashboards, logs, and metrics. - Technologies: kubernetes; terraform; argocd; cilium; sealed-secrets; prometheus; grafana; loki; postgresql ### yamiat.com - Period: since 2020 A production side project in continuous development since 2020. From 2020 to 2025 it ran serverless on AWS using CDK, Node.js Lambdas, AppSync, Cognito, EventBridge, and a single-table DynamoDB model. - Personal ownership: I owned the full AWS architecture, infrastructure as code, data model, application code, and self-mutating deployment pipeline. - Client relevance: Hands-on production experience with serverless APIs, SQS/SNS messaging between services, S3 static asset hosting via CloudFront, and DynamoDB access patterns. - Operational responsibility: Operated on AWS for five years, then migrated to a self-operated Kubernetes platform in 2025; continuously developed in production since 2020. - Technologies: aws; aws-cdk; lambda; node.js; appsync; dynamodb; cognito; eventbridge; sqs; sns; s3; cloudfront; codepipeline; next.js; react; typescript; graphql; dotnet; postgresql ### Agent tooling & MCP - Period: since 2026 The workflow behind my daily AI usage: a custom MCP server, skills and extensions for coding agents, and deterministic tooling around AI output — built and used daily, not demoed. - Personal ownership: I build and maintain the MCP server, agent skills, extensions, and deterministic checks around generated work. - Client relevance: The system makes AI-assisted delivery bounded, inspectable, and reviewable instead of treating model output as an unchecked result. - Operational responsibility: Used in daily engineering work with human review before changes are accepted. - Reviewable workflow example: Reviewable example: issue-scoped agent → isolated worktree → deterministic test and build gates → human-reviewed pull request. - Technologies: typescript; mcp; ai-agents; node.js