Potsdam, HPI, Security Engineering
jhannes@hpi:~$
Jhannes Ernesto
Reimann.
MSc Computer Science at Hasso Plattner Institute, Security focus. I build tools for problems I actually have: DNS measurements, pocket pentest rigs, therapy search, mail downgrade tests. Breaking things to understand them better.
open to security rolesPotsdam, DEMSc HPI 25 to 27
jhannes@hpi: ~/now live
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.%#*#*=::::::::.::::$ whoami
Jhannes Ernesto Reimann, MSc HPI, SAP working student
$ cat current.txt
MSc Computer Science, HPI, Security Engineering
Apr 2025 to Apr 2027
$ cat work.txt
Working student, SAP Sustainability (GreenToken, SDX)
Nov 2025 to present, Potsdam, hybrid
$ ls stack
PythonRust/WASMReact 19Tailwind v4Flask/FastAPIKaliPostfix/Dovecot
# full timeline below
featured projects
5
focus
how systems fail, how they work
02, Experience
01
Working student, Sustainability Solutions (GreenToken and SDX)
SAP, part time
Nov 2025 to present, Potsdam, hybrid
- Support development of Sustainability Solutions
02
Working student, Information Security
Die Autobahn GmbH des Bundes, work study
Nov 2024 to Nov 2025, Hohen Neuendorf, on site
- ISMS and CMDB tools (fuentis)
- Management of critical infrastructure, ISO 27001 and BSI Grundschutz, BSI audits
- Microsoft Office scripts and Power Automate
03
Student assistant, Institute for Computer Science
University of Potsdam, contract
Oct 2022 to Nov 2024, Potsdam
- Tutor for programming fundamentals, algorithms and data structures (Java, Python, C, basic assembler) with PD Dr. Henning Bordihn
- Tutor and assistant in software engineering with Prof. Dr. Anna-Lena Lamprecht: worksheets, guest talk on AI tools, UML and Java reviews, Python GitLab automation
Education
Hasso Plattner Institute
E1Master of Science, Computer Science
Apr 2025 to Apr 2027
Network security, TCP/IP, Security Engineering
University of Potsdam
E2Bachelor of Science, Computer Science and Computational Science
Sep 2021 to Sep 2025, grade 1.9
Thesis: LLM vs DocTool on Javadoc, hybrid approach, 2025
Friedrich-Gymnasium Luckenwalde
E3Abitur, general university entrance qualification
Jul 2013 to May 2021, grade 1.7
03, Projects
Built for problems I actually have.
Keep scrolling. Vertical scroll drives this row sideways.
02, IoT pentesting, Pi 4
chonkyflipper
Portable rig: WiFi, BLE, IR, sub GHz, Zigbee, NFC plus BadUSB, controlled from a phone.
Raspberry Pi 4Kali ARM64FlaskVite + Tailwind
04, Mail security, HPI NSIP 25/26
email-client-selftest-service
Deliberately strict mail server that shows if your client survives STARTTLS downgrade.
Python stdlibFastAPIPostfix/Dovecot
04, Research
Bachelor thesis, 2025
Possibilities and Limits of AI Applications for the Creation and Analysis of External Software Documentation. University of Potsdam, Software Engineering.
63.1% vs 52.5%
LLM (o4 mini) vs DocTool on alibi detection accuracy
0.45 vs 0.18
Logic errors per file: LLM Javadoc vs human originals
Hybrid
Result: formal checks plus semantic LLM is the best docs workflow
Tested if LLMs beat rule based DocTool on finding weak alibi Javadoc and on writing new Javadoc. LLMs win on semantics, lose on hallucinated logic when identifiers are obfuscated.
05, Awards
HackHPI 2025, Digital Health Innovation Forum, HPI
HackHPI 2025, WIN
Challenge 1, Ottobock, Accessibility
Team IncluGo: custom mapping for people with disabilities. Swipe obstacles that matter to you, preview the route before you leave, contribute back to OpenStreetMap. Built as a React app.
Team: Aleksandrs Morgensterns, Samuel Lessmann, Niels G., Adam Brangenberg, Benedikt Liebold, Jhannes Ernesto Reimann. Jury: Ottobock, HPI.
Presenting
Digital Health Innovation Forum, HPI 2025, live demo of inclu-go routing.
IncluGo on the phone: swipe obstacles, check the route.
06, Contact
Let's talk security.
Open to working student, internship and junior security or platform roles. Fastest way is email, I read everything.