Skills

I have over 20 years worth of development experience in various industries and languages. Working with over 20 different programming languages, I have not listed all the languages and software I have worked with, only the ones I have worked with in the last 5 years.

  • Rust - 9 years
  • Go - 1 year
  • Scala - 7 years
  • Java - 6 years
  • C# - 13 years
  • Sql - 10 years
  • Mongo - 7 years
  • CSS - 3 years
  • HTML5 - 8 years

About Me

Over the last 2 years I have been working at Stealth company writing software and libraries to help the company index and store acedemic papers on the internet for ease of categorizing the papers and serving only the relavent information to our clients. All of this has been done in Rust for speed. I have also been doing some Embded Rust for another project where we need to do some calculations on embeded hardware before this data is being sent to the servers.

I have also been working on some electornics projects where i am designing, fabcricating, and writing the firmware and software for several kinds of electronics projects. Including bigger motherboards for larger equipment all the way down to small sensors that has to last years on a single battery charge. Technologies includes but are not limited to BLE, WiFi, Lora, ESB Protocol, GNSS, LTE, Proprietary Communication Stacks. All sorts of sensors from temperature, humidity, High precision Motion Sensors, Gyroscopes, and Magnetometers. A variaty of operating environments from cold storage sensors -18c to 55c depending on the application. All of the firmware has been written in rust, some with realtime OS and async features and some without async where timeous response is of utter importance.

Before this I was working at Absa on the Fleetmanager team. I have over 20 years worth of development experience in various industries and languages. My dad taught me how to code as he thought it would take off when I grew up and boy was he right. I then developed my love for coding even further, it became my hobby and then my job. It's the best feeling in the world to write a piece of code and then refactor it to be as succinct and elegant as possible. I strive for code perfection and follow strict standards.



I first started programming when I was 6 years old, and starting doing electronics projects when i was 10, nothing spectacular but back then I thought it was amazing. I started on an old commodore 64 with basic and some machine language. I got into it because my dad introduced me to the world of programming and electronics, telling me he thought that is the way of the future, this was in 1988. He only taught himself how to program so that he can teach me, but he worked in the field of electronics for the national broadcaster by maintaining and improving the broadcasting equipment, he was an electronic engineer at the time. That is how my love for programming and electronics started and over the years I have taught myself several languages. I have used over 15 languages.I love programming. It's been my passion for the last 32 years. To be paid to do my hobby and be able to help out those in need of my special skills is worth a lot to me. I see myself programming until I retire, even if it's only for myself. I love learning new programming languages and new ways of re-implementing something within a language I already know. I am in the business of solving problems and business is good, and it is very rewarding holding a device that you have designed from concept to physical device, including the firmware and software that makes it work and solve real world problems.

How I keep my skills sharp

At previous companies I run a Code Friday group where we talk about programming and where I teach the junior to senior developers more about functional programming and how it all fits together with the libraries that I write and they use. I read up on the languages I use and I frequent the gitter chats for several languages and libraries including scala, cats, rust and haskell.

In this world of growing AI Coding tools, I keep myself up to date with how they all function and where their shortcomings are. This helps to use the tools more effectively and allow me to write world class code without the downfalls of halucinations and AI Code slop. AI helps non programmers, juniors, and mid level delopers get an idea together, and it helps senior developers that understand the coding environment and problem domains elevate what is posisble and produce world class systems in a fraction of the time it used to take.

Contact Details

Ryno Kotze
Cape Town
South Africa
kotze.ryno@gmail.com

Education

University of Life

Architecture and Programming• Never stop learning.

I have over 20 years of experience in this field and I am always learning new things and new ways of doing things.

TDF Computer People

Structured Programming• April 2004

COBOL, Structured programming skills, Nassi-Shneiderman Design skills, System Analyses

Schweizer-Reneke High School

High School Deploma • December 2000

Matriculated, Subjects: Mathematics, Science, Accounting, Biology, Afrikaans, English, Computer Science

Work

Absa Group

Rust Developr • March 2024 - Present

Writing software and libraries to help the company index and store acedemic papers on the internet for ease of categorizing the papers and serving only the relavent information to our clients. All of this has been done in Rust for speed.

Absa Group

Lead Product Engineer • April 2023 - March - 2024

Working on the Fleetmanager team. Designing and implementing a Fleet manager suite of products to help manage their fleet of servers and services such as database deployments.

Supra Oracles

Lead Software Engineer • December 2022 - January 2023

Working on Blockchain smart contracts and VRF.

Tari Labs

Senior Rust Developer • March 2022 - December 2022

I am working on the Yat team building new features and fixing old features on the backend in Rust. Currently working on new features that I can not speak of yet until they reveal the new interface and features.

Wealthmigrate

Technology Architect / Technology Lead • January 2018 - March 2022

I was employed to help drive the in-housing of development. They were using an outsourcing company to make their software, I have since redesigned and implemented an in house solution where we focused on micro to help with the scaling of the system. Implemented a wallet system in Rust where we have wallets in our system to represent client accounts with a transactional system and a book building system that we use to build books on investment fund raisins for both real estate investments and alternative investments. I also built a rules engine that helps with fast pivoting of business rules so that we don't have to keep developing the same part when rules change. I have also integrated multiple payment gateways into the wallet system that I have built so that our clients only have 1 wallet and we manage all the integration for ease of use for our clients. The rules engine was also built in Rust using 3 of the Rust libraries I have written and published to crates.io.

Konga Online - Century City

Software Architect • May 2017 - November 2017

I was employed to help them drive the micro service architecture and to help them scale their systems as they can only do 1 order every 2 seconds and my new Order system i wrote can do 5000+ orders per second with 5 nodes running. Unfortunately Konga Online closed down their operations in South Africa and all the South African employees got retrenched.

Full Facing - Contermanskloof

Software Architect • March 2015 - April 2017

I am working on the backend architecture for all the systems developed by Full Facing, I have designed and implemented a MicroService Architecture using a message bus for inter service communication which is being used currently to rewrite the current computicket system, we have already implemented a ticketing platform and all of this I have implemented using the Scala language and Function Programming Design patterns.

Mxit Lifestyle - Stellenbosch

Senior Developer • May 2012 - November 2014

I worked on some C# services and I am currently the Android development Team Lead. Leading a team of 3 people developing in java and scala on android. Responsible for developing the android version of mxit using the latest android technologies.

Maitland Group - Cape Town

Senior C# Developer • March 2012 - April 2012

I was contracted to develop internal systems for the Maitland group using ASP.Net MVC3 with the Razor View engine, JQuery, EF 4 and MS SQL.

MWEB - Cape Town

Senior Developer • May 2011 - Februart 2012

I was contracting as a senior developer to mweb working on various software and projects as they saw fit. Working in an agile team using SCRUM methodologies and pair programming

Sybrin Systems - Fourways

Senior Developer • April 2010 - April 2011

WorI was employed as a senior Developer to work on the new version of their flagship software and to handle ad hoc software requirements that they receive from clients ranging from document tracking systems to bank teller systems and hardware drivers. I was also responsible for the design and implementation of a new version of their document tracking system that we wrote in F#/

Transunion - Illovo

Analyst Developer • October 2008 - May 2009

I was employed as a developer to head up new projects and help out with old project where there was a need of new and innovative ways of doing things. The role ended up more as maintenance of existing systems

Netstar - Midrand

Software Developer / Web Developer • September 2007 - September 2008

Netstar is the leading vehicle tracking and recovery company in South Africa. I have mostly developed web based applications and some smart clients for Netstar. I also wrote a mapping control that is being used on most of the websites Netstar hosts. Because of the nature of the work I cannot disclose any groundbreaking breakthroughs that I have helped make.

Ernst & Young - Johannesburg

Software Developer / Data Analyst • January 2004 - August 2007

Ernst & Young is one of the 4 major auditing firms in the world. I specialized in software development and data analyses for 3 years. I wrote most of the software that the Data Analysts should be using to do their jobs. I also wrote a tool that is currently being used as a global standard in doing a specialized type of Data Analytics that is at the forefront of that field

Projects

Personal


Zestbay: Persistent Audio Routing for Linux

GitHub: github.com/lemonxah/zestbay

Zestbay is a specialized PipeWire patchbay designed to solve the lack of persistence in standard Linux audio routing. Building on the foundations of Helvum, Zestbay introduces a rule-based engine that automatically restores complex node connections and applies persistence across system reboots. Developed in Rust with a focus on performance and reliability, it provides a seamless way to manage professional audio workflows, ensuring that virtual cables and hardware interfaces remain correctly mapped without manual intervention.


Drawing Tablet: Android-to-PC Graphics Interface

GitHub: github.com/lemonxah/drawing_tablet | Implementation:Drawing Tablet

A cross-platform solution designed to transform an Android tablet into a high-performance graphics tablet for desktop environments. The project focuses on low-latency input transmission and pressure-sensitivity support, enabling precise artistic control in professional software like Krita and Photoshop. It involves developing both a native Android client and a desktop server component, utilizing Rust to ensure memory safety and efficient data handling between devices.


D3 Node Engine & No-Code Flow Builder

Engine: github.com/lemonxah/d3ne-rs | Implementation: github.com/lemonxah/nocode

A high-performance node-based logic engine implemented in Rust, inspired by Unreal Engine’s Blueprints. This project provides a robust backend for visual programming, allowing users to build complex logic flows without writing code. The companion NoCode application demonstrates the engine's capabilities, providing a graphical interface for creating and executing dynamic data-driven workflows.


QueryLib: Custom DSL Lexer & Parser

GitHub: github.com/lemonxah/querylib

A sophisticated Rust library featuring a custom lexer and parser designed to translate a high-level query language into specific database syntaxes. Currently supporting MongoDB, it features a powerful macro system for type-safe field queries, ensuring compile-time validation of database interactions and reducing runtime errors in complex data environments.


FunLib: Functional Programming Utilities

GitHub: github.com/lemonxah/funlib

A comprehensive Functional Programming library for Rust that extends the language's native capabilities. It provides a suite of utilities and abstractions designed to facilitate cleaner, more declarative code, focusing on immutable data patterns and higher-order functions to improve maintainability and local reasoning in large-scale Rust applications.


Cargo Semver Update (GitHub Action)

GitHub: github.com/lemonxah/cargo_semver_update

A DevOps utility integrated as a GitHub Action to automate Semantic Versioning within Rust projects. It streamlines the release workflow by automatically checking and updating `Cargo.toml` versions based on commit history and conventional changelog standards, ensuring consistent dependency management and CI/CD reliability.


Rust Ecosystem: Performance & DX Tooling

Repository: github.com/lemonxah

Active contributor to the Rust ecosystem, focusing on the development of specialized libraries that enhance developer productivity. This includes the implementation of memory-efficient data structures and high-performance utilities designed to bridge the gap between low-level system control and high-level Developer Experience (DX), ensuring that complex backend systems remain maintainable without sacrificing execution speed.


Language Engineering: Custom DSL Implementation

Focus: Lexer/Parser Development

Specialized in Language Engineering within the Rust environment, specifically the creation of Domain-Specific Languages (DSLs). This work involves architecting custom lexers and parsers that translate abstract logic into actionable database queries or engine commands. By leveraging Rust's macro system, these implementations provide compile-time safety and rigorous type-checking for dynamic, user-defined inputs.


Wealthmigrate / Wealth Point

I have built multiple microservices in Scala and Rust, most notably I have built a Multi Currency wallet system with full transactional history with the ability to write the transactions to a blockchain and interfaced with third party wallet systems like Lemonway and banking apis. The wallet system is written in Rust. I have also implemented a No Code Node coding rules engine to allow for non developers to implement rule changes without writing code. This was written in Rust using several Rust libraries I have written and published to crates.io and they are available on my github page.

Full Facing

I have built multiple systems on the microservice architecture I designed and built for Full Facing. They are high load systems with between a hundred thousand and eight hundred thousand requests per second. I have also built a ticketing system that can allocate tickets without allocating any duplicate tickets with a performance of just over eight hundred and fifty thousand tickets allocated per second. These high load systems are currently in place in big retail outlets in the country. I have built all of this using RabbitMQ, MongoDB, Scala, Akka, Play Framework, Spray and Scalaz

Ernst & Young

Various tools to help EY employees worldwide improve on their data analytics from spreadsheet formatting applications to file cleaning and applications specifically designed to do data analytics on financial systems. The latest tool that I designed and developed as my own initiative rivals a tool called TablePro (Link) that downloads data from a SAP system. My tool not only downloads the data but also performs cleaning of the data and analyses of the data downloaded, this tool supports Ernst & Young in this new field of data analytics and has put Ernst & Young at the lead of all auditing firms at SAP data analytics. This tool is also used worldwide. Companies the tool is being used and has been used:

  • - South Africa

    • Anglo Platinum
    • Transnet
    • Engen (CTN)
    • Palaborwa Mining Corporation

  • - England

    • The teams that went to England to do data analyses on these clients used my tool in conjunction with SQL2005
    • TFL (Transport for London)
    • BBC (British Broadcasting Company)
    • Barclays
    • Invista

Netstar

Unfortunately due to Non Disclosure I can not expand on all the projects I was involved with. Mapping Control I have written a mapping control for most of Netstar’s websites used to locate and recover units. Guardian Website backend I wrote the backend of the website used for Netstar’s latest unit the Guardian.

Testimonials

  • I can think of several adjectives to describe Ryno, who I have had the pleasure of knowing and working with for the past four years in my role as the Product Owner: meticulous, logical, innovative, precise, versatile, enthusiastic, candid, skillful, collaborative, inspiring to name but a few. Apart from being an absolute wiz at mathematics, Ryno has an incredible knack for spotting potential system issues during planning and design even before they arise or development kicks off. He can translate complex technical and business requirements into world-class, functional architecture or technology solutions. He has been the driving force behind almost all of our architectural and technological decisions at our company and a phenomenal mentor to junior and senior software developers sharing his vast knowledge, keen interest in emerging technologies, and passion for software development. He believes in doing things right the first time. Ryno's vast experience and skills truly make him an invaluable asset to any company.

    Mercia Jankowitz

  • Ryno is, hands down, the most gifted technologist I've had the privilege and pleasure to work with. He has an incredible knack for mathematics, logic and reason and a memory to go with it! He is conscientious, with an eye for detail and an acumen for spotting "what ifs". Ryno is a true polyglot developer, always choosing the best tool/language for the given situation. His hobby projects lead him to keep pushing boundaries with technology outside of work, which translates to fresh ideas brought into the business. From an architectural perspective, he has lead the business in choosing tech stacks, technologies and languages, from simple consoles to complex event-driven integrations and everything in between. He is a fantastic mentor to junior (and senior) team members and is always willing to lend a hand and share knowledge. I would hire and/or work with Ryno again in a heartbeat!

    Werner Calitz

  • I've known Ryno Kotzé for more than 5 years now since the start of 2016. I've worked with him for more than 4 of those 5 years: More than 1 Year at Full Facing and for the past 3 years at Wealth Migrate. Ryno has played an instrumental role in the technical knowledge and experience I've gained over the past 5 years I've worked in the enterprise software industry. His vast amounts of experience and technical prowess have enabled him to be a credible curator of information about technologies and industry know-how. This experience and technical prowess are responsible for the efficient rate of learning I've experienced over the past 5 years by revealing the critical path to follow which avoids time-wasting pitfalls and gets you to your goal with the least amount of time. I see Ryno as a mentor, friend, and leader and I'm sure that he will be an asset to any Software Development team.

    Guandré Voigt