Ivan Voras, PhD, Developer in Zagreb, Croatia

Ivan Voras, PhD

Open Source Developer

Location
Zagreb, Croatia
Toptal Member Since
August 26, 2014

Ivan is primarily a back-end developer with 18+ years of experience architecting and implementing server-side solutions, including distributed platforms, such as blockchains, chat servers, and game back-ends. He has handled DBA operations, developed modules for PostgreSQL, and has experience developing firmware for IoT devices. He helped establish the Toptal blockchain specialization, served as a tech screener, and lectured for Toptal Academy.

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Portfolio

Equinox Vision d.o.o.,
Go, Unity, DevOps, Management, PostgreSQL, HTTP API, Crypto, Scraping...
Ideja na kvadrat (Self-employed)
PostgreSQL, Python, Go, C, Database Design, Django, Blockchain, Cryptography...
Freelance
Java, PHP, Python, C++, C, Database Design, System Administration...

Experience

Open Source - 20 yearsPostgreSQL - 18 yearsPython - 15 yearsCTO - 11 yearsSystem Architecture - 10 yearsDatabase Design - 10 yearsBlockchain - 8 yearsGo - 6 years

Location

Zagreb, Croatia

Availability

Part-time

Preferred Environment

Visual Studio Code (VS Code), Go, Git, GCC, Vim Text Editor, Linux, Python, SQLite, Back-end Development, WhatsApp

The most amazing...

...thing I've developed is a blockchain from scratch (github.com/ivoras/daisy).

Work Experience

2019 - PRESENT

CTO and Founder

Equinox Vision d.o.o.,
  • Architected and developed a highly scalable back-end architecture to handle hundreds of thousands of users for the global AR platform the company is developing.
  • Assembled a team of developers, designers, and marketers to launch the company as a startup.
  • Managed the startup's founding team for the early stage of the company.
Technologies: Go, Unity, DevOps, Management, PostgreSQL, HTTP API, Crypto, Scraping, System Architecture, Software Architecture, CTO, API Design, Architecture, Databases, Kubernetes, Back-end Development, Back-end Architecture, API Integration, Technical Leadership, Full-stack, Team Leadership, SaaS, APIs, Augmented Reality (AR), AR Interfaces, REST APIs, Financials, Back-end, Scripting, Docker, Docker Compose, Web Security, REST, Scalable Architecture, Due Diligence, Distributed Systems, Puppet, Non-fungible Tokens (NFT), Solution Architecture, GPT, Email, OpenAI GPT-3 API, Generative Pre-trained Transformers (GPT), Machine Learning, ChatGPT API, ERC-20
2015 - PRESENT

Consultant | Developer

Ideja na kvadrat (Self-employed)
  • Developed the back end for a Bitcoin explorer tool with PostgreSQL, Redis, and Python.
  • Handled DBA and DevOps for large companies and startups.
  • Worked with a self-employment company as a consultant and freelance in web app architecture, big data processing architecture, and high-performance network services.
Technologies: PostgreSQL, Python, Go, C, Database Design, Django, Blockchain, Cryptography, Web Services, HTTP API, Bitcoin, Cryptocurrency, Ansible, Linux, Security Policies & Procedures, Linux Servers, Amazon S3 (AWS S3), Crypto, ARM, Makefile, CMake, Amazon Web Services (AWS), PCB Design, Scraping, Data, System Architecture, IT Consulting, Cloud, Software Architecture, CTO, MySQL, Technical Writing, API Design, Embedded C, PCB, Microcontrollers, Architecture, Databases, Kubernetes, Flask, Back-end Development, Back-end Architecture, API Integration, Web Development, Technical Leadership, MQTT, Cassandra, Full-stack, Solidity, API Development, Team Leadership, SaaS, APIs, Open Source, REST APIs, API Documentation, Back-end, Scripting, Data Pipelines, Apache Kafka, Swagger, Docker, Docker Compose, REST, Blockchain & Cryptocurrency, Ethereum, Decentralized Finance (DeFi), Ethereum Smart Contracts, Software Design, Scalable Architecture, Web Scraping, Data Engineering, Distributed Systems, Container Orchestration, Non-fungible Tokens (NFT), Solution Architecture, GPT, Email, G Suite, SMTP, IMAP, Raspberry Pi, Internet of Things (IoT), Embedded Linux, LAMP, Database Performance, ChatGPT API, ERC-20
2000 - PRESENT

Open Source Developer

Freelance
  • Authored dozens of open source projects, including applications and libraries.
  • Created a faster, faster, high-performance memory cache server with more features than Memcached.
  • Built a module for PostgreSQL (written in C) to extend the full-text-search facility with support for the Croatian language.
  • Developed a module for PostgreSQL (written in C) to support on-the-fly.
  • Created a client-side public key encryption module in JavaScript and PHP for secure user authentication without SSL.
  • Developed a fixed-point header library in C for environments without floating-point support (e.g., embedded).
  • Created an encrypted notepad app for desktop and Android editing, directly saving encrypted files.
  • Updated a blog regularly at http://ivoras.net/blog/tree/.
Technologies: Java, PHP, Python, C++, C, Database Design, System Administration, Embedded Software, Bitcoin, Cryptocurrency, Linux, Crypto, Android, System Architecture, IT Consulting, Software Architecture, MySQL, Technical Writing, API Design, Django, Architecture, Databases, GDB, Valgrind, Back-end Development, Back-end Architecture, API Integration, SaaS, APIs, Open Source, REST APIs, API Documentation, Back-end, Scripting, HTML, Apache Kafka, Swagger, Docker, Docker Compose, REST, Microservices, Blockchain & Cryptocurrency, Smart Contracts, Software Design, Distributed Systems, Container Orchestration, Solution Architecture, GPT, Email, SMTP, IMAP, Raspberry Pi, Embedded Linux, LAMP, ERC-20
2016 - 2021

Senior Lead PHP Developer

Foothold Technology, Inc.
  • Troubleshot performance issues and daily database issues for a large web app.
  • Worked with and consulted the DevOps team in closing hard-to-catch issues relating to the Linux kernel and PostgreSQL internals.
  • Participated in planning and designing sysadmin/ops activities and requirements.
  • Managed a data processing pipeline using Airflow and Snowflake.
Technologies: PHP, SQL, Zend Framework, Angular, PostgreSQL, AngularJS, Ajax, Snowflake, Embedded Software, System Architecture, IT Consulting, Amazon Web Services (AWS), Software Architecture, Architecture, Databases, Back-end Development, Back-end Architecture, Web Development, Technical Leadership, Full-stack, Data Pipelines, Web Security, REST, JavaScript, CSS, HTML5, Data Science, Scalable Architecture, Data Engineering, Solution Architecture, LAMP, Performance Tuning, Database Performance
2015 - 2018

C Developer

EvoBits Information Technology SRL
  • Developed the back end for a blockchain explorer product using Python and PostgreSQL.
  • Created a system that periodically imports blockchain data into PostgreSQL for analytics purposes.
  • Developed forks of the Bitcoin codebase to work as altcoins.
Technologies: C, Bitcoin, Extreme Programming, Unit Testing, CentOS, Bash, Python, Bitcoind, IT Consulting, Back-end Development, Back-end Architecture, REST, Blockchain & Cryptocurrency, Smart Contracts, Software Design, Distributed Systems, C++, Puppet, Performance Tuning, Database Performance
2014 - 2016

CTO and Founder

Akira Industries
  • Developed multiple iterations of a PCB board for an IoT product.
  • Assembled and tested pre-production PCB boards and made them ready for production.
  • Managed PCB manufacture and assembly of pre-production PCB samples with a Chinese manufacturer (JLCPCB).
Technologies: Electronics, Digital Electronics, PCB Design, CTO, Embedded C, PCB, Microcontrollers, Architecture, Back-end Development, Back-end Architecture, Renewable Energy, Technical Leadership, Team Leadership, REST, Software Design, Container Orchestration, Puppet, Raspberry Pi, Internet of Things (IoT), IoT Protocols, Performance Tuning, Database Performance
2007 - 2015

Kernel Developer

FreeBSD
  • Wrote kernel-side code dealing with storage systems (GEOM).
  • Designed and implemented a device-level journaling module.
  • Designed and implemented a virtual storage module.
  • Gave talks at annual FreeBSD conferences about my work with storage systems (GEOM).
  • Participated in the vibrant international community of users and developers.
Technologies: C, SQLite, FreeBSD, System Architecture, Software Architecture, API Design, GDB, Valgrind, API Development, REST APIs, API Documentation, Back-end, Scalable Architecture, C++, Raspberry Pi, Embedded Linux, Performance Tuning, Database Performance
2001 - 2015

Internet Services Architect

University of Zagreb
  • Designed and implemented the core of a web content management system back when they were a new concept (2001-2002).
  • Designed the faculty web and student information systems as a technology and product architect.
  • Designed a very modular web application framework.
  • Designed and optimized the design of the database to include recent PostgreSQL features.
  • Designed and implemented the server-side environment based on FreeBSD for high performance and uptime.
  • Spearheaded the implementation of new technologies into existing products and processes.
  • Completed a PhD in an efficient multithreaded client-server architecture.
Technologies: PostgreSQL, PHP, Database Design, System Administration, Security Policies & Procedures, Architecture, Back-end Development, Back-end Architecture, Technical Leadership, API Development, Team Leadership, Open Source, Web Security, REST, JavaScript, CSS, HTML5, Software Design, Scalable Architecture, Email, SMTP, IMAP, Performance Tuning, Database Performance

Experience

Written a Book About Running an Early Stage Startup in Eastern Europe

https://amzn.to/44hixwc
Explore the startup landscape of East European countries and review the differences in the concepts of limited liability companies and company equity in approaching the market. This quick reference guide is structured around the primary author, Ivan Voras, with additional chapters written by guest collaborators. The chapters are concise and focus on overcoming the various obstacles startups may face. You'll benefit from regionally relevant advice on finding problems worth solving as a startup, how to hire people, how to raise investment rounds, and how to find and communicate with investors.

Daisy Blockchain

https://github.com/ivoras/daisy
A private blockchain where blocks are SQLite databases, in Go.

ESP8266 3LED

https://easyeda.com/84e3e8ee/ESP8266_3LED_1_3-9442fb3e6844443299208137daf8dcda
An IoT board around ESP-12S module (with ESP8266) powered by a 9V-18V DC jack, with three signaling WS2812 LEDs, two buttons, an OLED display, a beeper, and a temperature and humidity sensor. The board is meant to act as a hub and connect to other devices with more sensors.

Bullet Cache

A memory cache server faster than Memcached (in its timeframe) and with more features, such as cache record tagging and tagged expiry. It also has more flexible operations on multiple cached items.

My Electronics Blog

http://ivoras-electronics.tumblr.com/
Since late 2015, I've been doing an increasing amount of work with Arduinos and similar-style electronics. I've created a blog to share what I've learned and to learn from the comments!

I'm currently interested in low-power design and solar power.
Image of Installing Django on IIS: A Step-by-Step Tutorial publication
Publication

Installing Django on IIS: A Step-by-Step Tutorial

https://www.toptal.com/django/installing-django-on-iis-a-step-by-step-tutorial
Image of Guide to Multi-processing Network Server Models publication
Publication

Guide to Multi-processing Network Server Models

https://www.toptal.com/software/guide-to-multi-processing-network-server-models
Image of Software Development Anywhere: My Distributed Remote Workplace publication
Publication

Software Development Anywhere: My Distributed Remote Workplace

https://www.toptal.com/remote/software-development-anywhere-my-distributed-remote-workplace
Image of Working with ESP32 Audio Sampling publication
Publication

Working with ESP32 Audio Sampling

https://www.toptal.com/embedded/esp32-audio-sampling

Skills

Languages

Go, SQL, Python, C, Snowflake, Stored Procedure, Regex, PL/pgSQL, Embedded C, Solidity, PHP, Java, Bash, HTML, JavaScript, CSS, HTML5, C++

Frameworks

Django, Knockout (Knockout.js), Flask, Bootstrap, Swagger, Unity3D, Unity

Libraries/APIs

API Development, REST APIs, LibC, Sockets, HTTP API, POSIX, Arduino RTC, Python Imaging Library, LocalStorage, AES, Puppet.js, Social APIs, Pygame, FFmpeg, SDL, Google API, pcap, ZeroMQ

Tools

Ansible, PuTTY, Vim Text Editor, Git, Apache, GitHub, Django-admin-tools, Trac, Subversion (SVN), Bitbucket, KVM/Qemu, NGINX, Mercurial, SQL Prompt, VirtualBox, Makefile, CMake, Valgrind, MQTT, Docker Compose, Puppet, Apache Airflow, Postfix, Notepad++, MediaWiki, HSQLDB, cURL Command Line Tool, Trello, GCC, VPN, GDB, G Suite

Paradigms

Concurrent Programming, Back-end Architecture, Database Design, REST, Hosting, Object-oriented Programming (OOP), DevOps, Socket Programming, Microservices, Real-time Systems, High-performance Computing, Refactoring, Clean Code, Data-driven Programming, Object-oriented Design (OOD), Management, Unit Testing, Data Science

Platforms

Blockchain, Ubuntu, Linux, LAMP, Raspberry Pi, BSD, Red Hat Linux, Debian Linux, CentOS 6, CentOS, Kubuntu Linux, Linux RHEL/CentOS, Unix, FreeBSD, Docker, Ethereum, Embedded Linux, Xen, Django CMS, Android, Raspbian, Kernel Programming, Keychain, Arduino, Amazon Web Services (AWS), Kubernetes, Apache Kafka, Visual Studio Code (VS Code)

Storage

PostgreSQL, Database Performance, SQLite, Memcached, Cache, FlatFile, Database Administration (DBA), Databases, SQL Stored Procedures, Database Modeling, NoSQL, LevelDB, DB, Redis, smbd, MySQL, Amazon S3 (AWS S3), Data Pipelines, Cassandra, SQL Performance, MySQL Daemon, Internal Databases, Database Replication, JSON, Apache Derby, Firebird, LVM, CouchDB, Berkeley DB, MongoDB

Other

Performance Tuning, Software Architecture, Cryptocurrency, Cryptocurrency Development, Architecture, Version Control, IMAP, SMTP, TCP/IP, SSL, Bitcoind, Back-end Development, System Architecture, HTTP, Open Source, Bitcoin, System Administration, SSH, Memory Mapped Files, IT Consulting, Software Engineering, Linux Servers, Data, CTO, Technical Writing, API Design, API Integration, Web Development, Technical Leadership, SaaS, APIs, API Documentation, Back-end, Scripting, Software Design, Scalable Architecture, Solution Architecture, Email, Game Back-end, Documentation, White Papers, Security Policies & Procedures, ESP8266, Hardware, Electronics, Firmware, Network Programming, WebSockets, Bluetooth, Distributed File Systems, Cryptography, Ethernet, Networks, Web Services, UDP, Encryption, TCP, Embedded Systems, Site Speed Optimization, Public-key Cryptography, SFTP, FTP, GNU, Unix/Linux Virtualization, RSync, Multithreading, Writing & Editing, iSCSI, Hash, Regular Expressions, HTTP Server, Data Structures, Prototyping, Embedded Software, Crypto, Cryptocurrency APIs, Blockchain & Cryptocurrency, Scraping, Cloud, Team Leadership, Augmented Reality (AR), AR Interfaces, Web Security, WhatsApp, Smart Contracts, Decentralized Finance (DeFi), Ethereum Smart Contracts, Web Scraping, Data Engineering, Distributed Systems, Container Orchestration, Non-fungible Tokens (NFT), Computer Science, GPT, Internet of Things (IoT), IoT Protocols, OpenAI GPT-3 API, ChatGPT API, ERC-20, Data Warehousing, Data Warehouse Design, Consulting, Digital Electronics, Algorithms, ARM Embedded, Apache Cassandra, Electrical Engineering, System Design, NFS, Unix Shell Scripting, Genetic Algorithms, RPC, Memory Profiling, Social Media Integration, Single Sign-on (SSO), Protocol Buffers, RSA, OAuth, Peer-to-peer Networking, Lean Development, Embedded Hardware, Software Consulting, Technical Consulting, ARM, PCB Design, PCB, Microcontrollers, Renewable Energy, Full-stack, Financials, Due Diligence, Generative Pre-trained Transformers (GPT), Machine Learning

Education

2006 - 2011

PhD Degree in Computer Engineering

University of Zagreb - Croatia