Verified Expert in Engineering
Software Engineer and Web Developer
Janko is a software engineer and architect specializing in blockchain and focusing on decentralized finance and self-sovereign identity (SSI). He has years of experience with Bitcoin, Ethereum, Quorum, Fabric, Tendermint, Cosmos blockchains, and Hyperledger Indy and Aries SSI solutions. Janko has recently applied modern distributed systems, cryptography, and blockchain theory to solving SSI-related problems.
Git, Erlang, Rust, Go, Python, Linux, Blockchain
The most amazing...
...project I've worked on was a secure, enterprise-level crypto wallet with tagging features for searching and filtering encrypted records.
Blockchain and SSI Engineer
- Created self-sovereign identity (SSI) wallet that stores students' verifiable credentials.
- Wrote back-end system for issuing verifiable credentials to institution's users.
- Designed and researched self-sovereign identity libraries to use.
ASU Pocket - University Technology Office
- Built a web service that integrated Hyperledger Aries and the university's system, allowing it to issue verifiable credentials to its students.
- Guided the SSI implementation process of the entire project.
- Built several proof-of-concept applications that showcase the usage of verifiable credentials in education.
- Worked on developing features for the new DAG platform.
- Improved the wallet capabilities of the DAG platform.
- Created the trigger mechanism to allow smarter DAG nodes.
- Worked on picking the correct blockchain technology for the client's needs.
- Implemented a prototype on the Tendermint blockchain platform.
- Wrote integration services in Golang, which serve as a blockchain's outer layer.
- Worked on designing the prototype for a platform on top of blockchain in the pharmaceutical industry.
- Developed prototype smart contracts on Ethereum, using Solidity.
- Wrote an engine in Python which integrated with Ethereum.
- Architectured the platform.
- Implemented the solution using Hyperledger and Python.
- Coordinated with end-user application team.
Senior Blockchain Developer
6fusion (via Toptal)
- Wrote software in Go which interacts with a blockchain platform.
- Worked with the Quorum platform.
- Used Docker and kubernetes for deployment.
Solidity/Blockchain Expert with Go Experience
Fractal Blockchain (via Toptal)
- Contributed to software written in Go which interacts with Ethereum nodes (with geth nodes specifically).
- Reviewed and improved smart contracts written in Solidity.
- Reviewed and improved software interacting with the Bitcoin network.
- Developed a secure crypto-wallet intended to be used for Hyperledger Indy.
- Supported the Indy-SDK project.
- Created proprietary software solving SSI-related problems on top of Hyperledger Indy.
- Bulit a system of pluggable crypto-wallet storage back-ends which allows for enterprise-scale wallets.
- Developed the Number Discovery Platform using Python and Gevent.
- Extended the PhoneID product written in Python and Bottle.
- Created a URL-shortening service using Python and Flask.
- Built a Number Deactivation product using Python.
- Wrote an internal HR application using JSP.
- Refactored an internal voting system written in a custom in-house framework.
- Supported and extended an internal forum written in JSP.
- Wrote a web crawler and scraper using Python and Beautiful Soup.
- Developed a custom content manager application back-end using Django.
- Created web microservices using Python.
Hyperledger Indy Crypto Wallethttps://github.com/hyperledger/indy-sdk
Some of the features that distinguish this wallet:
1. mechanism for searching through encrypted entities using tags
2. multiple encryption keys using Elliptic Curve Cryptography
3. pluggable storage system supporting enterprise-scale crypto wallets
Identity Solution for Red Cross Refugees on Top of Hyperledger Indy
Multichain Tracker (Blockchain Data Tracker and Aggregator)
It integrated with most common blockchains (Bitcoin, Ethereum, etc.) through their APIs, and fed data through web sockets to a front-end dashboard.
Reward System on Top of Ethereum Blockchain
Pharmachain (Provenance and Supply Chain Blockchain)
Website and Web App Used in BEST
Refactored and extended the internal application.
Number Discovery Platformhttps://www.telesign.com/products/sms-api/
Phone ID Servicehttps://www.telesign.com/products/phone-id/
Blockchain Platforms, Ethereum, Blockchain, Hyperledger, Kubernetes, Docker, Hyperledger Fabric, Linux, Hedera Hashgraph
Distributed Ledger Technology (DLT), Distributed Ledgers, Decentralized Applications, Distributed Systems, Self-sovereign Identity (SSI), Directed Acrylic Graphs (DAG), Applied Cryptography, Ethereum Smart Contracts, Smart Contracts, Quorum, IPFS, Bitcoin, Peer-to-peer Networking, Hyperledger Aries, Cryptocurrency, Non-fungible Tokens (NFT), Hashgraph Technology, EOSIO, EOS, Cryptography
Tendermint, Pyramid, Jakarta Server Pages (JSP), Flask, Django
Hyperledger Indy, Git, Stellar SDK
Concurrent Programming, Agile, Functional Programming
Relational Databases, Cassandra, BigchainDB
Beautiful Soup, Gevent, Bottle.py, Node.js, Web3.js
Bachelor's Degree in Software Engineering
University in Belgrade - Belgrade, Serbia
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