Ivan Voras

Zagreb, Croatia

Member since June 18, 2014

Ivan is primarily a back-end developer with 10+ years of experience in architecting and implementing server-side solutions, including non-web-related distributed platforms such as Bitcoin, chat servers, and general client-server solutions. He has handled DBA operations, developed modules for PostgreSQL, operating system kernel modules (FreeBSD), and new algorithms. He is interested in general client-server problems and distributed apps.

Ivan is now available for hire

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Portfolio

Ideja na kvadrat (Self-employed)
C, Go, Python, PostgreSQL
FreeBSD
C
Freelance
C, C++, Python, PHP, Java

Experience

Database Design, 10 years
PostgreSQL, 10 years
FreeBSD, 8 years
C, 8 years
DBA, 8 years
Python, 7 years
System Architecture, 5 years

Availability

Part-time

Preferred Environment

Linux, Vim, GCC, Eclipse, Git, Go

The most amazing...

...thing I've developed is a Bitcoin fork.

Employment

Developer
Ideja na kvadrat (Self-employed)
2015 - PRESENT
- Developed back-end for a Bitcoin tool.
- Handled DBA and DevOps for both large companies and startups.
Technologies: C, Go, Python, PostgreSQL
Kernel Developer
FreeBSD
2007 - PRESENT
- Wrote kernel-side code.
- Designed and implemented a device-level journaling module.
- Designed and implemented a virtual storage module.
- Gave talks at annual FreeBSD conferences.
- Participated in the vibrant international community of users and developers.
Technologies: C
Open Source Developer
Freelance
2000 - PRESENT
- Authored dozens of open source projects, including applications and libraries.
- Created a high performance memory cache server that was faster and had more features than Memcached (http://sourceforge.net/projects/mdcached/).
- Built a module for PostgreSQL (written in C) to extend the full-text-search facility with support for the Croatian language (https://bitbucket.org/ivoras/pgdict_hrsufx).
- Developed a module for PostgreSQL (written in C) to support on-the-fly encryption of common data types (https://bitbucket.org/ivoras/pgenctypes/).
- Created a client-side public key encryption module in JavaScript and PHP for secure user authentication without SSL (https://bitbucket.org/ivoras/rsalogin/).
- Developed a fixed-point header library in C for environments without floating point support (e.g. embedded) (http://sourceforge.net/projects/fixedptc/).
- Created an encrypted notepad app for desktop and Android for editing and directly saving encrypted files (http://sourceforge.net/projects/enotes/).
- Updated a blog regularly at http://ivoras.net/blog/tree/.
Technologies: C, C++, Python, PHP, Java
Internet Services Architect
University of Zagreb
2001 - 2015
- Designed and implemented the core of a web content management system back when they were a new concept (2001-2002).
- Worked 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 efficient multithreaded client-server architecture.
Technologies: PHP, PostgreSQL

Experience

Encrypted Notepad (Development)
http://sourceforge.net/projects/enotes/
A desktop application and an Android application for editing and saving encrypted text files.
Bullet Cache (Development)
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.
Needle Search Server (Development)
https://bitbucket.org/ivoras/needle
A very fast and streamlined full text search server using Google's LevelDB for storage. It acts as a pure REST server over FastCGI and is implemented completely in C++.
My Electronics Blog (Other amazing things)
http://ivoras-electronics.tumblr.com/
Since late 2015, I've been doing 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.
Guide to Multi-processing Network Server Models (Publication)
https://www.toptal.com/software/guide-to-multi-processing-network-server-models
In this article, Toptal engineer Ivan Voras provides a useful overview and comparison of multi-processing network server models, with the goal being to take some of the mystery out of writing high performance networking code. The article is intended for "system programmers", i.e., back-end developers who will work with the low-level details of their applications, implementing network server code.
Software Development Anywhere: My Distributed Remote Workplace (Publication)
https://www.toptal.com/remote/software-development-anywhere-my-distributed-remote-workplace
Working as a remote software development freelancer has many benefits, but setting up an effective distributed working environment can be a real challenge. In this article, Toptal Engineer Ivan Voras describes how he leverages SSH and a number of related technologies, along with the Raspberry Pi and ownCloud, to be able to work effectively from anywhere.
Installing Django on IIS: A Step-by-Step Tutorial (Publication)
https://www.toptal.com/django/installing-django-on-iis-a-step-by-step-tutorial
Although the most wide-spread and supported way of running Django is on a Linux system (e.g., with uwsgi and nginx), it actually doesn't take much work to get it to run on IIS. In this article, Toptal Engineer Ivan Voras walks you through a step-by-step tutorial, clearly explaining how to install Django on IIS.

Skills

Languages
Python, C, SQL, PHP, PL/pgSQL, Regex, Pascal, Java, Object Pascal, JavaScript, C++, Go, Stored Procedure
Frameworks
Django, Bootstrap 3, Bootstrap, Knockout.js, Flask, Boost C++, Android SDK
Tools
PuTTY, Ansible, Mercurial, SQL Prompt, Apache, Trac, Django-admin-tools, VirtualBox, Bitbucket, Subversion, GitHub, KVM/Qemu, Vim Text Editor, Nginx, Postfix, Markdown, cURL Command Line Tool, Virtualenv, Eclipse, Git, Trello, GCC, VPN, Notepad++, MediaWiki, Eclipse IDE, Asana, HSQLDB
Paradigms
Database Design, Object-oriented Programming (OOP), Socket programming, REST, DevOps, Concurrent Programming, Back-end Architecture, Refactoring, Functional Programming, Clean Code, Data-driven Programming, Real-time systems, Object-oriented Design (OOD), Cloud Development, High-performance Computing
Platforms
LAMP, Unix, FreeBSD, CentOS 6, CentOS, Raspberry Pi, BSD, Linux, Ubuntu, Ubuntu Linux, Linux RHEL/CentOS, Debian Linux, Kubuntu Linux, Win32, Amazon Web Services (AWS), Xen, Android, Django CMS, Arduino, WinNT, Java SE, Embedded, Raspbian
Storage
FlatFile, DBA, PostgreSQL, Memcached, Cache, SQLite, Database Performance, smbd, Redis, DB, LevelDB, MySQL, Database Modeling, NoSQL, Database Replication, Cloud, Cassandra, Internal Databases, MySQL daemon, MongoDB, Berkeley DB, JSON, SQL Performance, SQL Stored Procedures, CouchDB, Apache Derby, Firebird, LVM
Misc
Memory Mapped Files, System Administration, Bitcoind, SSL, Back-end Development, System Architecture, HTTP, Open Source, SSH, TCP, UDP, Web Services, Networks, Ethernet, Cryptography, SMTP, SFTP, FTP, GNU, Linux redhat, Unix/Linux Virtualization, TCP/IP, Distributed File Systems, Data Structures, Documentation Writing, HTTP Server, Regular Expressions, Hash, iSCSI, Writing, Site Speed Optimization, Encryption, Bitcoin, RSync, Multithreading, Network Programming, Security Policies & Procedures, AES, Peer-to-Peer networking, CRUD, OAuth, RSA, Protocol Buffers, SSO, Social Network Integration, Memory profiling, Keychain, Algorithms, LocalStorage, RPC, Genetic algorithms, Lean Development, Public-key cryptography, Version Control, IMAP, NFS, Apache Cassandra, Kernel programming, System Design, Architecture, Prototyping, AJAX, Embedded Systems, Electrical Engineering, Unix Shell Scripting, Firmware, Electronics, Hardware, ESP8266, ARM Embedded, Martini, Bluetooth, Software Architecture
Libraries/APIs
JSON REST API, Sockets, LibC, Lazarus, HTTP API, POSIX, Java Security, Puppet.js, jQuery, ZeroMQ, pcap, Google API, PyGTK, SDL, FFmpeg, Pygame, Social APIs, ODBC, Python Imaging Library, Masonry, WebSockets