Marvin M.-AI Engineer & Architect · LLM and Multi-Agent Systems
Check rate
Experience
Co-founder & CTO · Freelance Software Engineer (AI & SaaS)
Self-employed
- Self-employed · Berlin, Germany
- Co-founded the company and own the entire technical side: product architecture, backend, frontend, infrastructure and operations.
- Designed and built the Automated Booking System (ABS) as well as the core platform and payment logic.
- Development of AI-powered SaaS products, from architecture through backend and frontend to production operation.
- Technical consulting on product architecture, data protection and permissible automation.
- Building, running and monetising my own API products for AI agents, each available as a REST interface and as an MCP server.
- Full ownership of architecture, infrastructure, billing, legal texts and go-to-market.
Co-founder & CTO
takemeto.ai
- Full technical ownership: product architecture, backend, frontend, infrastructure, operations.
- Built the multi-agent pipeline: orchestration of specialised LLM agents, tool access over MCP, model-agnostic routing with fast models at runtime and cost-efficient models for batch pipelines.
- Designed and built the Automated Booking System along with the core platform and payment logic.
- Established an evaluation and regression harness across 24 personas. Result: hallucinated itinerary stops cut from 43 to 0, AI cost down 91 percent at unchanged answer density (model-agnostic routing, batching, prompt optimisation, a custom context and memory protocol, pre-evaluated RAG setups).
- Stripe payment infrastructure including checkout, subscriptions, webhooks and settlement between the GmbH and the Inc. OAuth via Google and Microsoft Entra ID.
- Separate staging and production environments, CI/CD, monitoring.
- Built the engineering team: role profiles, technical candidate assessment, selection and onboarding.
- Legal assessment of the automation under German, EU and US law, deriving hard technical limits.
TECHNOLOGIES: LangGraph, MCP, Claude API, TypeScript, Node.js, React Native, Supabase, PostgreSQL, Docker, Stripe, OAuth 2.0, CI/CD, Hetzner
Freelance software engineer
Lakeside Park Capital GmbH
- Development of AI-powered SaaS products, from architecture through backend and frontend to production operation.
- Technical consulting on product architecture, data protection and permissible automation.
TECHNOLOGIES: TypeScript, Node.js, React.js, PostgreSQL, LLM integration, Docker
Founder, engineer and operator
own product
- One social video URL returns metadata, insights, transcript, parametrically selectable frames and on-screen text via OCR, as a single JSON response in a unified schema across six platforms.
- OCR per frame with a confidence score and bounding box for each line of text.
- Access via REST, via MCP over Streamable HTTP, and through a complete OpenAPI 3.1 specification. Typed errors make failed calls self-correcting for agents.
- Per-call billing from $0.002 with no subscription, via Stripe or via x402 in USDC.
TECHNOLOGIES: MCP, OpenAPI 3.1, Whisper, OCR, TypeScript, Node.js, Stripe, x402
Founder, engineer and operator
own product
- Condenses Binance spot price data from one minute to one day into a token-efficient market state, instead of handing raw price series to a language model.
- Output covers a candle codec, SAX shape signature, chart patterns, support and resistance clusters, regime classification and interpreted indicators.
- Every pattern carries an evidence block with a backtested hit rate, a 95 percent confidence interval and no lookahead. Deterministic: identical candles, identical output.
TECHNOLOGIES: Python, TypeScript, MCP, OAuth, Stripe, x402, statistical analysis, backtesting
Founder, engineer and operator
own product
- Content and site structure are generated and published autonomously by language models, with human effort limited to guardrails and quality control. Every claim is validated against a checked source.
- Full technical delivery including frontend, backend, hosting and billing.
TECHNOLOGIES: TypeScript, Next.js, PostgreSQL, Stripe
Concept and requirements analysis
AI agent CRM for cross-border trade China / Europe
- 33-page sprint and requirements plan for a CRM platform driven by AI agents.
- Integration concept for 1688, 17TRACK and WeChat. Staged model covering proof of concept, MVP and several feature waves, including effort estimates.
Head of AI & Fullstack Software Engineer
Aachen Institute for Nuclear Training GmbH
- Responsible for the company's entire AI development, from agenda and business case through to production rollout.
- AI-driven digitalisation of internal processes with the specialist departments, from needs analysis and prototype to rollout and training.
- Project lead for AI software projects including resource coordination, team leadership and reporting to management.
- Backend systems in Java and Spring Boot 3 for control, data management and analysis of plant measurements.
- Interfaces in Vue.js and React.js for operating and visualising measurement systems.
- Design and implementation of REST APIs for integrating measurement devices and third-party systems.
- Technical interface between parent and subsidiary company on all software and AI matters.
TECHNOLOGIES: Java, Spring Boot 3, Vue.js, React.js, REST, PostgreSQL, LLM integration
Mathematical-technical software developer (dual study programme)
Aachen Institute for Nuclear Training GmbH
- Involved in production projects from early on, independently owning development tasks and sub-projects, continuously alongside the degree.
- Scope and responsibilities matched the fullstack role described above.
TECHNOLOGIES: Java, Spring Boot, Vue.js, React.js, REST, SQL
Dewabit
- Three-week software development internship.
Industry experience
See where this freelancer has spent most of their professional time.
Experienced in Information Technology, Education, and Banking and Finance.
Business area experience
See which departments and functions this freelancer has contributed to most.
Experienced in Information Technology, Product Development, Project Management, and Human Resources.
Summary
Full-stack and AI engineer focused on LLM and multi-agent systems. Software engineer first, AI as an accelerator: daily work with agentic harnesses since summer 2025 (Claude Code, Codex, DeepSeek Harness, Hermes, OpenClaw, OpenCode, OpenRouter), with custom MCP servers, skills and plugins built for them and more than 150 billion tokens processed in total. Writing code since the age of 13, with my own projects running alongside school and university throughout, and won my first programming award at 16.
Skills
- Languages: Typescript, Javascript, Python, Java, Kotlin, C#, C++ (Basics)
- Frameworks & Ui: React.Js, Vue.Js, Next.Js, Node.Js, Spring Boot 3, React Native, Fastapi
- Ai & Agent Systems: Llm Integration (Claude, Gpt, Gemini), Multi-Agent Orchestration, Mcp (Model Context Protocol), Function Calling, Tool Use, Rag, Vector Search, Model-Agnostic Routing, Prompt And Context Engineering, Evaluation And Regression Testing For Llm Systems, Agentic Development Workflows
- Apis & Interfaces: Rest, Openapi 3.1, Oauth 2.0 (Google, Microsoft Entra Id), Webhooks, Rate Limiting, Mcp Over Streamable Http
- Payment Providers: Stripe (Checkout, Subscriptions, Webhooks, Statement Descriptors, Payouts), X402 (Usdc) For Autonomous Agent-To-Api Billing
- Data & Infrastructure: Postgresql, Supabase, Firebase, Docker, Ci/Cd, Cloud Deployment, Monitoring, Separate Staging And Production Environments
- Methods & Leadership: Business Case Development, Requirements Analysis, Sprint And Release Planning, Project Management, Team Leadership, Recruiting And Technical Assessment Of Developers
Languages
Education
Bachelor of Science, focus on mathematical-technical software development (MATSE) · Applied Mathematics and Computer Science
Friedrich-Wilhelm-Gymnasium Cologne
Abitur · Cologne, Germany
BilinGo
Germany
Statistics
Experience
Global experience
Expertise
Qualifications
Profile
Frequently asked questions
Have questions? Find more information here.
Marvin is based in Berlin, Germany.
Marvin speaks the following languages: German (Native), English (Advanced), Latin (Advanced).
Marvin has at least 8 years of experience. During this time, Marvin has worked in at least 7 different roles and for 7 different companies. The average length of individual experience is 1 year and 9 months. Note that Marvin may not have shared all experience and actually has more experience.
Based on recent experience, Marvin would be well-suited for roles such as: Co-founder & CTO · Freelance Software Engineer (AI & SaaS), Co-founder & CTO, Freelance software engineer.
Marvin's most recent position is Co-founder & CTO · Freelance Software Engineer (AI & SaaS) at Self-employed.
In recent years, Marvin has worked for Self-employed, takemeto.ai, Lakeside Park Capital GmbH, own product, and AI agent CRM for cross-border trade China / Europe.
Marvin is most experienced in industries like Information Technology, Education, and Banking and Finance.
Marvin is most experienced in business areas like Information Technology, Product Development, and Project Management. Marvin also has some experience in Human Resources.
Marvin has recently worked in industries like Information Technology, Education, and Banking and Finance.
Marvin has recently worked in business areas like Information Technology, Product Development, and Project Management.
Marvin holds a Bachelor in Applied Mathematics and Computer Science.
Marvin will be available full-time from September 2026.
Daily rate distribution
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Average rates for similar positions
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The average daily rate is the mean of all daily rates from recent contracts of comparable freelancers on our platform.
The median daily rate is the middle value of all daily rates — half of comparable freelancers charge less, half charge more. Unlike the average, it is barely affected by outliers.
Calculated based on our freelancers’ daily rates as of 22 Sep 2026. Actual rates may vary depending on seniority level, experience, skill specialization, project complexity, and engagement length.
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