Discover the Expertise and Innovation at

A Vision in Tech is the brainchild of David Schmid, a domain where technology meets innovation and expertise.

We specialize in state-of-the-art software engineering with robust security measures to develop solutions that withstand the test of time and technology.

Based in Vienna, is a developing scalable and secure solutions and empowering businesses to manage their digital assets.

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Behind the Code: David Schmid

David Schmid is a seasoned Software and Security Engineer with an extensive background in backend engineering, cryptographic protocols and security compliance.

He holds a Master's degree in Computer Science, combining academic and practical expertise, essential for delivering effective software solutions.

Having worked in diverse environments ranging from multinational corporations to freelance consultancy, he has refined his skills in various technologies such as C, Python, Rust, WebAssembly, C# and SQL.

Personal Data

  • Name: David Schmid
  • Nationality: Swiss
  • Date of Birth: 30.05.1984
  • Family Status: Proud husband and father of two.
  • Email:
  • Phone AT: +43 660 8114761
  • Phone CH: +41 76 3100186
  • GitHub: 5n00py
David Schmid

Experience Freelancing

  • Since: November 2023, working as a freelance Software and Security Engineer in Vienna, Austria
  • Licence: Officially recognized with a business licence, certifying freelance operations in data processing and information technology
  • Client Engagement: Engages closely with clients to understand their software and security needs
  • Engagement Types: Open to project-based work, long-term contracts, and consulting roles
  • Open Source: Contributes to personal open source projects
  • Skill Development: Improving skills in emerging technologies like Rust and WebAssembly

Payment Industry

  • Role: Software and Security Engineer at Worldline and PostFinance AG, Switzerland (2018-2023).
  • API Development: Designed and developed APIs for financial transactions
  • HSM Programming: Developing cryptographic protocols for Hardware Security Modules (HSMs) in C.
  • PIN Migration Project: Led a critical PIN migration project for debit cards in Switzerland and Austria.
  • Compliance Audits: Contributed to compliance audits and emergency response team support.
  • ICT Security Officer: At PostFinance AG, focused on Payment Card Security and Cryptographic Key Management.
  • Technologies Used: Utilized Thales payShield, C#, SQL, and Java.
  • Security Compliance Officer: Responsible for PCI PIN compliance at PostFinance AG.
  • Industry Proficiency: Demonstrated dedication and proficiency in software and security engineering within the payment industry.

Academic Projects and Education

  • Degrees: Primary degree from ETH Zürich (2008); Master of Science in Computer Science, University of Hagen, Germany (2017).
  • Project Participation: Contributed to academic projects improving practical skills in software engineering and applied cryptography.
  • C Compiler Development: Contributed to C compiler development for a PD system, enhancing system-level programming knowledge.
  • Cryptography: Studied traditional and post-quantum cryptography.
  • E-Voting: Studied applied cryptography on E-voting systems, leading to the masters thesis on cryptographic remote voting systems.
  • Internship Experience: Developed a Java-based crossword generator tool during an internship.
  • Poker Application Project: At ETH Zurich, worked on a poker application featuring AI-driven poker bots and explored AI strategies.
  • Educational Journey: Balanced theoretical learning and practical application, laying the foundation for a career in software and security engineering.

Excavation Techniques and Records Management

  • Roles: Project Staff Member at Kantonsarchäologie Aargau (2017) and Excavation Technician at Österreichisches Archäologisches Institut in Austria and Egypt and the Stadtarchäologie Wien (2009-2015).
  • Tool Development: Developed an image data archiving tool; managed databases using Python, SQL, AutoCAD, NetworkTrafficView, nmap, and Traceroute.
  • Network Monitoring: Monitored network traffic for efficient data handling and storage in archaeological projects.
  • Excavation Technician Duties: Responsible for documentation and inventory of archaeological finds, utilizing database management and GIS tools.
  • Fieldwork Supervision: Supervised excavation sections in Egypt, managing hands-on fieldwork and site management.
  • Academic Pursuit: Obtained a bachelor's degree in Egyptology, deepening understanding of ancient cultures and preservation methods.
  • Technological Integration: Merged traditional archaeological practices with modern technological advancements in excavation techniques and records management.


  • Programming: C/C++, Python, Rust, C#, Java, Bash
  • Hardware Security: SafeNet HSM, payShield, Custom Firmware Engineering
  • Security Compliance: PCI DSS, PCI PIN, PCI P2PE
  • Database Management: SQL, imdas pro
  • Network Analysis: NetworkTrafficView, nmap, Traceroute, Wireshark
  • Web Development: HTML, CSS, JavaScript, WebAssembly
  • Other Tools: Git, JIRA, Jenkins, AutoCAD, ArcGIS, Neovim, Tmux, Docker, LaTeX, Debian Linux

Project References

Note: Due to confidentiality agreements, not all project references are listed.

PIN Security Migration

  • Description: Led the migration of millions of bank cards in Switzerland and Austria to improved PIN security standards.
  • Role: Project Lead, Lead Developer
  • Period: 2021-2023
  • Technologies: C, SafeNet, Ruby
  • Environment: Worldline, Backend API

eft/pos 2000

  • Description: Spearheaded the development of eft/pos 2000 (ep2 version 8) standards, integrating AES, TR-31, HKDF for secure EFT transactions.
  • Role: Lead Developer
  • Period: 2022
  • Technologies: C, SafeNet, Ruby
  • Environment: Worldline, Backend API

ATMfutura AES and TR-34 Migration

  • Description: Involved in upgrading multivendor ATM systems to AES encryption and implementing the TR-34 standard.
  • Role: Developer
  • Period: 2022-2023
  • Technologies: C, SafeNet, C#, Python
  • Environment: Worldline, Backend API


  • Description: Developed a GUI tool for generating UCAF test data in payment testing environments.
  • Role: Project Lead, Lead Developer
  • Period: 2021
  • Technologies: C#
  • Environment: Worldline, Testing

PCI P2PE Introduction

  • Description: Participated in the introduction and preparation for the initial audit of the PCI P2PE compliance standard.
  • Role: Contributor
  • Period: 2022
  • Technologies: PCI P2PE
  • Environment: Worldline, Compliance

PCI PIN Migration

  • Description: Migration to the updated PCI PIN standard version 3, ensuring enhanced security compliance.
  • Role: Compliance Officer
  • Technologies: PCI PIN, payShield HSM
  • Period: 2020-2021
  • Environment: PostFinance, Compliance

EMV Chip 21

  • Description: Migration to new EMV chip generation for a banks debit cards according to EMV standard
  • Role: Security Engineer, Compliance Officer
  • Technologies: EMV, payShield HSM, Chip card
  • Period: 2020-2021
  • Environment: PostFinance, Security, Compliance

Bankomat Security TR-34 Migration

  • Description: Migration to TR-34 compliant standards for ATMs.
  • Role: Security Engineer, Compliance Officer
  • Technologies: payShield, C#
  • Period: 2018-2020
  • Environment: PostFinance, Compliance, Testing


  • Description: Developed an AI-powered tool for auto-generating meaningful git commit messages.
  • Role: Maintainer, Developer
  • Technologies: Bash, Python
  • Period: 2023
  • Environment: Open Source


  • Description: Created a tool that enhances command-line search by integrating multiple utilities.
  • Role: Maintainer, Developer
  • Period: 2023
  • Environment: Open Source

pkr (Poker Library)

  • Description: Created a Rust library for evaluating Texas Hold'em poker hands.
  • Role: Maintainer, Developer
  • Technologies: Rust
  • Period: 2022-2023
  • Environment: Open Source

psec (Payment Security Library)

  • Description: Contributed to the psec Python package for retail payment transaction security.
  • Role: Contributor
  • Technologies: Python
  • Period: 2021
  • Environment: Open Source

soft-aes (AES library)

  • Description: Developed a Rust library providing a software-based implementation of AES.
  • Role: Maintainer, Developer
  • Technologies: Rust
  • Period: 2023
  • Environment: Open Source


  • Description: Created a GUI application for generating crossword puzzles, featuring a built-in editor.
  • Role: Software Engineering Intern
  • Technologies: Java
  • Period: 2017

Records Management Aargauisches Kulturgut

  • Description: Worked on a project dedicated to the documentation and management of cultural heritage.
  • Role: Developer
  • Technologies: Python, Database Management
  • Environment: Kantonsarchäologie Aargau

Ende-zu-Ende-Verifizierbarkeit kryptographischer Fernwahlsysteme

  • Description: Research thesis on the security of electronic remote voting systems.
  • Role: Thesis
  • Technologies: Research, Python
  • Environment: University
  • Period: 2016-2017

PD System

  • Description: Contributed to the development of a C compiler for a PD system.
  • Role: Contributor, Student
  • Technologies: C, lex, yacc
  • Environment: University
  • Period: 2015-2016


  • Description: Developed a Python library for lattice algorithms, crucial in post-quantum cryptography.
  • Role: Maintainer, Developer
  • Technologies: Python, numpy
  • Environment: University, Open Source
  • Period: 2015-2016