Gabriel
Mandtler
I build AI solutions and automations for companies: websites, workflows, agents and AI operating systems. My eye for clean processes and evidence comes from SAP projects and IT audit.
Get to know me.
I'm Gabriel, CEO of MGTI Consulting. I build AI solutions and automations.
Five years ago I stumbled into IT audit at PwC as a dual student — ITGC work as part of the financial-statement audit. I stayed because you really get to understand how a company runs: the audit looks straight at the systems and processes the business depends on.
After that I worked as an Associate in Finance Transformation, lifting legacy systems onto S/4HANA. The craft is process and documentation.
For two years I've been seriously playing with LLMs. Agentic development, automation (with n8n, Make.com and others), APIs. Not because I want to become a developer — because the delta is real: on a Sunday evening I ship faster than a junior team does in a week. That changes how I think about audit work.
In 2026 I co-founded MGTI Consulting GmbH with Ioannis Tsarmantidis. I am its CEO and lead the AI side of the business.
AI and automation, from idea to production.
AI websites
Websites with AI features, from design to deployment, built with agentic development.
AI operating systems for organisations
Skills, tools and knowledge brains: an organisation's knowledge and tools prepared so AI agents can work with them.
Automation & integration
Automation with n8n, Make.com and other tools, interfaces via REST APIs and webhooks, agents for routine work. I'd rather build for an hour than click for three.
AI consulting
Where does AI pay off in a company, and where not? Assessment, tool selection, pilot. I plan evidence and documentation from the start.
From auditor to founder.
Today I run MGTI Consulting. Before that, more than five years in Risk Assurance and Finance Transformation.
Founder & CEO · AI lead
Co-founded with Ioannis Tsarmantidis. I lead the AI side, from consulting to the built solution.
Building AI websites
AI operating systems for organisations: skills, tools and knowledge brains
AI automation and integration: workflows, interfaces, agents
AI consulting
Dual student, then Associate
ITGC engagements as part of the financial-statement audit, later SAP data migrations onto S/4HANA. B.Sc. at HWR Berlin in parallel.
ITGC: access, change, operations, backup
SAP data migration with Migration Cockpit, mapping and validation
Audit-ready documentation per IDW PS 330 / ISA 315
What I actually build.
No portfolio theatre. These solutions exist because a client asked whether it couldn't be simpler, or because I needed them myself.
Websites built with agentic development
Two client projects from design to deployment, delivered with agentic development.
- Front to back, including lead forms, CRM hookup, email
- Inbound categorisation & lead scoring
- Deployed on Hetzner, own domain, TLS, monitoring
Lead & task dashboard with agents
Business dashboard for a family business: leads, campaigns, agent-automated tasks.
- Pipeline: contact → qualification → proposal → close
- Campaign performance, cohort view, revenue forecast
- Task agents with modular context memory
- In production on a VPS, CI/CD via git hooks
Workflows for SaaS integrations
Automations with n8n, Make.com and other tools: traceable and debuggable.
- Complex flows via REST, webhooks, queue handling
- Retry logic and structured logging (no "why didn't this fire yesterday?")
- In-flight validation & transformation
Migration validator for SAP data
Python tool that checks Migration-Cockpit output against the target schema — before the productive run.
- Parses LTMC XML & staging tables, maps to corporate schema
- Completeness & plausibility at object, field and document level
- Emits audit-ready PDFs and a variance heatmap
- Saves ~2 days per delta run — the main reason it exists
What I actually know — rated honestly.
I don't inflate. 4 = I ship production with it. 3 = I deliver. 2 = I read docs first. 1 = I've tried it.
Where I've worked.
Industries I've worked in across client projects.
Publishing
Audit of the migration of several legacy systems to SAP S/4HANA. ITGC engagements as part of the financial-statement audit.
Energy
SAP S/4HANA implementation with focus on FI and MM. ITGC engagements as part of the financial-statement audit.
Telecommunications
High-volume transaction business. SoD and ITGC audit engagements.
Aerospace
SAP S/4HANA implementation with focus on FI and MM.
Healthcare
ITGC engagements as part of the financial-statement audit.
Gaming
ITGC audit as part of the financial-statement audit.
Let’s talk.
Migration lined up, audit finding on your mind, or curious what agentic development really delivers? Drop me a line. I usually reply the same evening.