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Marcus Hemmen.
DE / EN
Vol. 01 · April 2026 marcushemmen.de Available

Senior SAP Fiori · SAPUI5 · Freelance

Marcus Hemmen.

SAP applications your users actually enjoy using — built by a developer with thirteen-plus years of web DNA.

8+

years SAPUI5 & Fiori

14+

client projects

10+

industries

6

SAP modules

Start a project See the stack ↓

Contents

In this issue

  1. 01 Practice
  2. 02 Toolkit
  3. 03 Selected work
  4. 04 Background
  5. 05 Get in touch

§ 01

Practice

What I'll build for you.

Full coverage — from CDS view to production-ready Fiori app. No buzzwords, no demo theatre.

My focus is Fiori Elements with OData V4 and CDS views, plus ABAP RAP for clean backends. I take ownership from concept to production rollout — with code reviews, technical documentation and end-user training when needed.

“I'm equally at home in the SAP backend and on the frontend. That saves you the translation work between two worlds.”

Focus areas

  1. i

    Fiori Apps & Migration

    Greenfield apps, GUI-to-Fiori migrations, consolidation of UI5 landscapes. Launchpad and Theme Designer included.

  2. ii

    SAPUI5 Custom Development

    Complex custom apps with clean architecture, custom controls, proper routing. Built to be maintainable, tested, documented.

  3. iii

    Fiori Elements & OData V4

    List Report, Object Page, Overview Page. Full annotation power, cleanly modelled through CDS views.

  4. iv

    ABAP, RAP & Gateway

    RAP business objects, classic Gateway services, BAPIs, BADIs, MDG, performance tuning, full application logging.

  5. v

    Architecture & Consulting

    Reviews, greenfield concepts, best practices, end-user training — including prototyping with Adobe XD and Figma.

§ 02

Toolkit

Tools & methods

Production-tested. No buzzwords.

SAP Frontend
SAPUI5 · SAP Fiori · Fiori Elements · Business Application Studio · Fiori Launchpad · SAP Build / Theme Designer · SAP Screen Personas · Web Dynpro ABAP
SAP Backend
ABAP · ABAP RAP · OData V2 / V4 · CDS Views · SAP Gateway · BAPIs · BADIs · MDG
Web Technologies
HTML5 · CSS3 · JavaScript (ES6+) · TypeScript · jQuery · React · Angular · Node.js · IndexDB · REST · JSON · XML
Tooling & Process
Eclipse / ABAP Development Tools · Business Application Studio · Git · UI5 Tooling · Adobe XD · Figma · Jira
Data & Methods
SAP HANA · MySQL · Scrum / Agile · Code Reviews · Architektur-Beratung · Prototyping · Schulungen

SAP modules · shipped in

PM · MM · EWM · SD · HCM · PP · PS

Industries · delivered to

  • Public sector / Defence
  • Public employment authority
  • Automotive
  • Logistics & Transport
  • Mechanical engineering
  • Agriculture
  • Telecommunications
  • Utilities
  • Healthcare
  • Print systems
  • Housing industry
  • Public transport

§ 03

Selected work

Six excerpts from over fourteen.

Anonymised projects across industries and modules. Full list on request.

  1. S/4HANA migration with Fiori

    Design and build of multiple SAPUI5 apps and modernisation of SAP standard transactions via Screen Personas. Code reviews, best-practice guidance, end-user training.

    Tech SAPUI5 · Fiori · Screen Personas · OData V4 · ABAP · Scrum

  2. Fiori in SAP standard and MDG

    Custom Fiori app for picking serial-number-tracked items. BADI extensions for SD, Fiori apps inside SAP MDG.

    Tech Fiori · SAPUI5 · ABAP · BADI · MDG

  3. Fiori migration HCM

    Implementation and customer-specific extension of SAP standard Fiori apps in HCM. Migration planning consulting, extension of legacy Web Dynpro apps.

    Tech SAP Fiori · SAPUI5 · ABAP · Web Dynpro

  4. EWM consolidation workstations

    Outbound goods at consolidated workstations with order-based workflows. High-bay picking with UI5 surfaces, fully implemented on ABAP RAP and OData V4.

    Tech SAPUI5 · ABAP RAP · OData V4 · Fiori

  5. Drone flight planning

    Fiori Elements app for planning medical-supply drone flights. CDS views as semantic data model, OData V4 connectivity — fully developed in Business Application Studio.

    Tech Fiori Elements · SAPUI5 · OData V4 · CDS Views · BAS

  6. Offline-capable mobile maintenance

    Architecture consulting on modern frontend tech, offline functionality based on IndexDB for mobile devices. QR-code processing in the frontend, UI5-tooling-based build pipeline.

    Tech SAPUI5 · IndexDB · UI5 Tooling · SAP Gateway · QR codes

— Full project list on request

§ 04

Background

From full-stack to SAP specialist.

Thirteen years of code, five of web, eight of SAP — without a gap in between.

I started in 2012 with an apprenticeship as an IT specialist in Lower Saxony. Followed by a solid five years of full-stack web development with JavaScript, PHP, jQuery, React, Angular — online platforms, payment integrations, entry-management software, everything that makes the web fun.

In 2018 I moved fully into the SAP world — employed at two specialised SAP consultancies. Worked deep on Fiori, UI5, ABAP and RAP, wrote custom controls, built corporate-identity themes, and consulted on architecture and interfaces.

Since mid-2023 I run my own freelance practice — focused on serious SAP projects as an external developer or architect. Clean code, clear communication, agile delivery in Scrum.

CV

Full CV available on request — just send a mail

Languages

German · Native

English · Business fluent (B2)

§ 05

Get in touch

Let's talk.

Whether it's a concrete request or a casual intro — drop me a line.

marcus.hemmen@gmail.com

Send an email →

Location
Harsefeld, Lower Saxony
VAT
DE360056295

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