Nikola Klipa, Developer in Belgrade, Serbia
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Nikola Klipa

Verified Expert  in Engineering

Cryptocurrency Developer

Belgrade, Serbia
Toptal Member Since
April 11, 2018

Four years ago, Nikola started his blockchain obsession by reading a lot about blockchain and bitcoin, then Ethereum showed up which further peaked his interest and two years later, he started developing smart contracts on Ethereum. He is extremely good at optimizing code and has a strong knowledge base in data structures and algorithms. Nikola has worked in teams of all sizes and also as the only developer on projects.


Python, Ethereum, Solidity
PHP, Scala, Lua, Objective-C
Devana Labs
Symfony, PHP, Objective-C, Python




Preferred Environment

ITerm, GitHub, Remix IDE, Sublime Text, MacOS

The most amazing...

...thing I've worked on is Melon Mail—a fully decentralized email system based on Ethereum; used by MelonPort (one of the biggest companies in crypto world).

Work Experience

Blockchain Developer

2017 - PRESENT
  • Worked on MelonMain as Solidity developer—helping on some major security tasks.
  • Developed in Solidity on the Extend app; with an added responsibility for making all the decisions on the application architecture.
  • Built the community gateway for Ethfinex as a Solidity developer; it required that I familiarize myself with their contracts and to find a way to implement a voting system.
  • Led the Solidity development in making a Selenean framework for games on Blockchain.
  • Researched with a team on state channels, Plasma, and Plasma Cash (all scalable solutions for Ethereum).
  • Developed ERC20 (fungible) and ERC721 (non-fungible) tokens.
  • Gave a talk about Ethereum at one of the biggest conferences about cryptocurrencies in Serbia.
  • Worked as one of three tutors in the biggest Blockchain hackathon in Serbia and also developed the smart contract from where the users got their prizes from.
  • Held a three-day workshop about Solidity in our offices for people from Bosnia, Serbia, and Croatia.
Technologies: Python, Ethereum, Solidity

Software Engineer

2016 - 2017
  • Created a library for VPN on iOS, first of that kind, only a month after that possibility was given on iOS.
  • Worked on the back-end in Lua and Scala; was included in the architectural designs as the youngest developer.
  • Wrote an algorithm for calculating the best recommendations on mobile packages.
  • Made the VPN available to track all data on your iOS device.
  • Developed iOS applications for various companies: Telenor and Indosat.
  • Worked with different types of databases like Redis, MongoDB, Cassandra, and more.
  • Created a framework that generated code for iOS apps based on descriptions.
Technologies: PHP, Scala, Lua, Objective-C

Software Engineer

2015 - 2016
Devana Labs
  • Led a team of junior developers on a few projects.
  • Worked as the main architect of a web application for making and updating your CV.
  • Created a plugin for searching houses with more filters and notifications.
  • Developed messenger bots on Facebook using
Technologies: Symfony, PHP, Objective-C, Python

Extend is a Chrome browser extension that aims to bring the power of Ethereum blockchain to various social websites such as Reddit. It uses OAuth and Oraclize to get information.

Community Gateway

It's an application where you can submit proposals and vote for all others proposals based on the number of tokens you have in the moment of proposal approval.

Melon Mail

A fully decentralized email system, where all emails are encrypted and saved on InterPlanetary File System (IPFS).


An iOS application that lets you sync your music with people near you via Bluetooth. A full peer-to-peer application that lets you play music from one phone on another, just connect it with Bluetooth.

Event Planner

We made an event planner and won the first award at a Ticketmaster hackathon. There we used a few different APIs to find you everything about a specific event and give you a list of stuff you need to do with one click to make it happen.

Telenor Bot

We made a messenger bot for a hackathon held by the Telenor company. We made a bot using that was able to answer your questions, find the nearest store, and to recommend some phone-based answers.


We made a web application that took same news from different portals, made a short version of them, and gave you links to the full news on different portals.


We made an easy-to-use web app that helped refugees reconnect with lost relatives. Using this app, they are able to get the routes that refugees used most to cross the border, helped them pin them, and then leave a way to communicate this information for anyone that wants to connect with them.

ACM International Collegiate Programming Contest (ICPC)

Presented at my college as a member of a three-person team in the biggest international algorithm competition.

Serbian Algorithm Nationals

I won third place, twice and earned a second-place ranking, once in the Serbian nationals in algorithms during high school. I then continued with those types of competitions in BubbleCup (an international competition by Microsoft Development Center in Serbia) in college, as one of the few competitors that were able to go make it through qualifications.

Main architect and Solidity developer on project Selenean which is a platform that connects artists, games studios and gamers.
2013 - 2018

Bachelor's Degree in Computer Science

Union University Belgrade | School of Computing - Belgrade, Serbia


Facebook API, Google API


Sublime Text, Remix IDE, GitHub, ITerm


Ethereum, Blockchain, MacOS, iOS


Solidity, Lua, Scala, PHP, Python, Python 3, Objective-C






Cryptocurrency, Oraclize, OAuth

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