Hi, I'm Werner Bisschoff

Key Achievements

• Extended ERPNext using Python and JavaScript to improve workflows, pricing logic, and operational reporting (SQL)
• Built mobile features in Expo, including NFC (ISO 14443-4 APDUs) for e-paper price tags and card operations
• Migrated internal Retool workflows to Expo, significantly improving performance and maintainability

Infrastructure & Development

• Developed and maintained C# APIs supporting internal systems
• Provisioned AWS infrastructure with Pulumi and deployed services including Inngest and PayloadCMS
• Diagnosed and resolved issues in a large existing ERPNext installation
• Introduced LLM-assisted development workflows, improving debugging, code review speed, and internal developer productivity

Skills & Technologies

• Languages: Python, JavaScript, C#
• Mobile: Expo, React Native, NFC (ISO 14443-4 APDUs)
• Cloud & DevOps: AWS, Pulumi, Docker
• Frameworks: ERPNext, Inngest, PayloadCMS, Retool
• Databases: SQL
• Tools: LLM-assisted development, Git

Embedded Systems Development

• Designed an event-driven finite state machine for an I2C-based embedded system using C++ and FreeRTOS
• Developed ESP32 applications using C/C++ and ESP-IDF
• Integrated a configurable low-energy BLE stack for device communication
• Developed an active object within the QP Real-Time Embedded Framework (with QSPY) to simulate device behaviour

Tooling & Testing

• Built Python-based tooling for serial/BLE communication, including client-facing test executables
• Created Python hardware mocks for rapid iteration and early-stage testing
• Managed fast, reliable data interchange using a compact TinyFrame binary protocol
• Implemented asynchronous communication workflows with Python and Pytest

Skills & Technologies

• Languages: C, C++, Python
• Embedded Systems: ESP32, ESP-IDF, FreeRTOS, I2C
• Frameworks: QP Real-Time Embedded Framework (QP), QSPY
• Protocols: BLE (Low Energy), TinyFrame binary protocol
• Testing: Pytest, hardware mocking, serial/BLE communication
• Tools: State machines, event-driven architecture

DevOps & Infrastructure

• Created and maintained Docker containers for development and CI/CD testing
• Implemented and tested new services using RPC based on the SOME/IP protocol
• Used perf to reduce performance bottlenecks

Communication & Protocols

• Implemented IPC/RPC in existing C++ programs and Python scripts using Cap’n Proto and pycapnp
• Implemented a node tree to expose process-related variables and function calls to the IPC interface
• Analyzed TCP/UDP traffic with Wireshark

Team Leadership

• Led a small team using AGILE development practices
• Onboarded and mentored new software developers

Skills & Technologies

• Languages: C++, Python
• DevOps & Containers: Docker, CI/CD
• Protocols: SOME/IP, Cap’n Proto, TCP/UDP, IPC/RPC
• Tools: Wireshark, perf performance profiling
• Development: AGILE methodologies, team leadership, technical mentoring

Academic Projects

• NFC Payment System Emulator

  • Developed Android application using Kotlin to emulate ISO 14443 NFC payment system
  • Implemented protocol-level communication for payment card simulation with POS terminals
  • Gained deep understanding of NFC standards and mobile payment security protocols

• Microcontroller Development

  • Developed embedded systems logic using C and STM32 microcontroller family
  • Utilized STM32CubeMX for peripheral configuration and hardware abstraction layer generation
  • Implemented firmware for control systems and IoT applications

• PID Control System

  • Designed and implemented PID controller using Arduino to regulate DC motor voltage and speed
  • Tuned control parameters through empirical testing
  • Achieved precise motor control with minimal steady-state error and fast response times

• Data Analysis Pipeline

  • Built data processing workflows using Python and Pandas for large spreadsheet datasets
  • Applied statistical methods including linear regression and correlation analysis
  • Implemented introductory machine learning algorithms for data insights

Technical Skills Developed

• Programming Languages: Kotlin, C, Python, C++
• Embedded Systems: STM32, Arduino, microcontroller programming
• Tools & Frameworks: STM32CubeMX, Pandas, Android Studio
• Engineering Concepts: Control systems (PID), signal processing, protocol implementation (ISO 14443, NFC), statistical analysis, machine learning fundamentals