Dominik Krížo, Developer in Likavka, Žilina Region, Slovakia
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Dominik Krížo

Verified Expert  in Engineering

Software Developer

Likavka, Žilina Region, Slovakia
Toptal Member Since
August 9, 2021

Dominik is a highly skilled and experienced developer who has been programming since 13. With a strong foundation in object-oriented programming, he pursued further education in the field, finishing his bachelor's degree in informatics and eventually landed a role as an Android developer, working with Java and Kotlin. However, Dominik's passion for innovation and decentralization led him to explore the emerging field of blockchain development, where he has become an expert in Rust and WASM.


727 Ventures
Rust, Agile, Management, Audits, TypeScript, WASM, Blockchain, Smart Contracts...
Rust, Blockchain, Parity Polkadot, TypeScript, Unit Testing, Agile, Management...
Rust, Blockchain, Agile, WASM, Solidity, TypeScript, GitHub, Linux...




Preferred Environment

Visual Studio Code (VS Code), MacOS

The most amazing...

...thing I created and came up with was Sol2Ink, a transpiler from Solidity to ink!—eDSL on Rust for WASM smart contracts.

Work Experience

Head of Engineering

2022 - PRESENT
727 Ventures
  • Oversaw grant deliveries of our infrastructure products and managed developers working on our products.
  • Developed an application that transpiles Solidity code into ink! code.
  • Spoke at the sub0 developer conference about our infrastructure products.
  • Led auditing team during auditing of an ink! smart contract application of an NFT marketplace based on the Aleph Zero blockchain.
  • Provided support to users learning more about ink! smart contracts ecosystem.
  • Conducted an audit of a decentralized exchange based on the Aleph Zero blockchain and ink! smart contract language.
Technologies: Rust, Agile, Management, Audits, TypeScript, WASM, Blockchain, Smart Contracts, Linux, Docker, Parity Polkadot, MacOS, ERC-721, ERC-20, Architecture, Cryptocurrency, Ethereum Smart Contracts, Debugging, Programming, Slack, GitHub, Large-scale Projects, CI/CD Pipelines, Decentralized Finance (DeFi), Ethereum, Back-end, Node.js, Crypto, Unit Testing, Visual Studio Code (VS Code), Algorithms, Solidity

Collaboration Lead

2022 - 2022
  • Led a collaboration between my company and partner company, including project and partnership management.
  • Worked on transforming a lending platform from Solidity to ink!.
  • Led developers in the development, testing, and delivery of two applications.
Technologies: Rust, Blockchain, Parity Polkadot, TypeScript, Unit Testing, Agile, Management, Ethereum, Smart Contracts, Node.js, Linux, Docker, WASM, ERC-721, ERC-20, Cryptocurrency, Ethereum Smart Contracts, Debugging, Programming, Slack, GitHub, Large-scale Projects, CI/CD Pipelines, Decentralized Finance (DeFi), Back-end, Crypto, Visual Studio Code (VS Code), Algorithms, Solidity

Senior Blockchain Engineer

2021 - 2022
  • Worked on transforming a big decentralized exchange from Solidity language to ink! WASM smart contract language on Rust.
  • Made a huge contribution to OpenBrush, the standard library for ink! WASM smart contracts on Rust.
  • Came up with and created Sol2Ink, a transpiler based on Rust, which transpiles Solidity code to ink! code.
Technologies: Rust, Blockchain, Agile, WASM, Solidity, TypeScript, GitHub, Linux, Smart Contracts, Ethereum, Ethereum Smart Contracts, Docker, Parity Polkadot, ERC-721, ERC-20, Cryptocurrency, Debugging, Programming, Slack, Large-scale Projects, CI/CD Pipelines, Decentralized Finance (DeFi), Back-end, Node.js, Crypto, Unit Testing, Visual Studio Code (VS Code), Algorithms

Android Developer

2020 - 2021
DOXXbet & K-BET, sro
  • Participated in transforming legacy codebase from Java to Kotlin.
  • Took part in transforming an old UI to a new UI that's more user-friendly.
  • Wrote code for transferring user data from app to server and vice versa via REST API.
Technologies: Java 8, Kotlin, REST, Android, Git, Java, REST APIs, User Interface (UI), Android Studio, OOP Designs, Bug Fixes, Mobile App Development, Coroutines, Android SDK, Redmine, Front-end, Back-end, JSON, Dagger, Gradle, Lambda Functions, Mobile Development, APIs, Programming, Object-oriented Programming (OOP), Full-stack, Debugging, Mobile, Gaming, Refactoring, Mobile Apps


2019 - 2020
PROSOFT spol s.r.o.
  • Developed an application used by the Slovak national railway company to manage employees' attendance and issue and verify travel tickets.
  • Wrote unit tests for features and fixed bugs found by the unit tests.
  • Played a key role in delivering the MVP of the application on time to the customer for testing without any critical issues. This required working many extra hours.
  • Wrote back end for the application server to synchronize user local data with the server in Jakarta EE, utilizing Java server module.
Technologies: Android, Git, Scrum, Jenkins, Java 8, GitLab, Jira, SQL, Java, Unit Testing, Bug Fixes, Algorithms, Android Studio, OOP Designs, User Interface (UI), Windows, Agile, Mobile App Development, Android SDK, Java Application Servers, Java EE, Back-end, CI/CD Pipelines, Large-scale Projects, Dagger, Gradle, SQLite, Lambda Functions, Mobile Development, APIs, RxJava, Model View ViewModel (MVVM), Sybase, Databases, Programming, Object-oriented Programming (OOP), Full-stack, Debugging, Relational Databases, Mobile, Client/Server Networking, Minimum Viable Product (MVP), Refactoring, Mobile Apps


2018 - 2019
PROSOFT spol s.r.o.
  • Developed an Android app, written in C++ using Qt, that engine drivers in railway companies use to track their work, including what they did on their shift, note if something went wrong in their train, and keep track of train inventory.
  • Worked on the front end of the Android application, using QML.
  • Connected the front end with database data by writing SQL queries based on technical analysis done by the analyst.
Technologies: C++, Qt, QML, Android, SQL, Back-end, Front-end, Git, Scrum, Jira, CI/CD Pipelines, Mobile Development, Databases, Programming, Object-oriented Programming (OOP), Full-stack, CMake, Debugging, Relational Databases, Mobile, Mobile Apps

Sol2Ink – Solidity Code Transpiler to ink!
Sol2Ink is an application that transpiles Solidity smart contract application code to ink! and Rust code. This application aims to help developers and teams migrate from Solidity to ink! and WASM and make the learning curve of developers transitioning from Solidity to ink! easier. I came up with this idea and fully developed it, making it live.

OpenBrush - ink! Smart Contract Library
This is a smart contract library for ink! smart contracts. ink! is an eDSL on Rust for WASM smart contracts running on substrate blockchains. OpenBrush provides standards for ink! smart contracts and macros for easier development of ink! smart contracts. I hugely contributed to standards implementation, unit tests, integration tests, and maintenance regarding new ink! versions.

Android Betting App
An Android application for a Slovak betting company. I focused on refactoring legacy code from Java to Kotlin, reworking the application's UI, giving the application a new spirit and a nicer user experience, and connecting the application with the back-end database via a REST API.

Android App for Slovak National Railway Company

Ported an old application that was running on Windows CE and written in C++ to a new Android application in Java. The application is used by employees to report their attendance and information about trains, by conductors to issue and inspect travel tickets, and to manage ticket sales at train stations. The app runs on a local database that can be synchronized with the server database. I developed this application in an Agile team following a Scrum-like approach with stand-ups and two-week sprints. The CI/CD pipeline was managed with Jenkins.

Utilizing Advanced Data Structures
I completed two projects, written in Java, during a graduate course on algorithms and data structures. The goal of the projects was to provide evidence of real estate and lands; filter, add, edit, and delete these objects; and remain time and memory-efficient while doing so. I used my own components library with Graphics2D for simple UIs because they weren't the focus of the projects. When evaluated, each project received 13 of the 13 points available.

The first project focused on RAM efficiency, applying a K-Dimensional tree to determine how many keys each node had. Nodes were then compared by the key based on the level of the actual node being compared. The second project focused on storing large amounts of data, for example, in databases, so it aimed at disk efficiency using extensible hashing. Data was stored in the structure with keys, which were translated to hash and stored in the corresponding blocks in memory. If the blocks were full, they were stored in a congesting file.

School Project for Swapping Courses Between Students

A React-based web application, which allows students of the University of Žilina to swap courses with each other without the usage of some third-party social service like Facebook, WhatsApp, and others. The application works with the university's database, so the timetables are downloaded right from the university database, and swaps are also written to the database. The back end of this application is written in C#.NET, and the front end utilizes Node.js and React. My main contribution was testing, bug fixing, and enhancements to the application's back-end features.
2016 - 2020

Bachelor's Degree in Informatics

University of Žilina - Žilina, Slovakia


Node.js, REST APIs, Web3.js, Google Maps API, RxJava, jQuery, React


Android Studio, Git, GitLab, Jira, IntelliJ IDEA, Gradle, GitHub, Slack, Jenkins, Mathematica, Redmine, Unity 5, Java Application Servers, CMake


Android SDK, Parity Polkadot, Qt, Dagger, Unity, Unity3D, Next.js


C++, Java 8, Kotlin, Solidity, Java, UML, Rust, WASM, TypeScript, SQL, JavaScript, QML, C#, HTML, Python, C#.NET, PHP, CSS, Assembly


Agile, Scrum, Unit Testing, Mobile Development, Object-oriented Programming (OOP), Refactoring, Management, Model View ViewModel (MVVM), REST


Windows, Android, Blockchain, Ethereum, Mobile, MacOS, Firebase, Visual Studio Code (VS Code), Java EE, Linux, Docker, Web


JSON, MySQL, SQLite, Oracle SQL, NoSQL, Sybase, Databases, Relational Databases


OOP Designs, Algorithms, Data Structures, Bug Fixes, Crypto, Mobile App Development, Back-end, Decentralized Finance (DeFi), CI/CD Pipelines, Large-scale Projects, Lambda Functions, Programming, Full-stack, Debugging, Smart Contracts, Ethereum Smart Contracts, Cryptocurrency, Architecture, Minimum Viable Product (MVP), Gaming, ERC-20, ERC-721, Mobile Apps, Audits, User Interface (UI), Web Development, APIs, Game Development, User Authentication, Client/Server Networking, Non-fungible Tokens (NFT), Coroutines, Front-end, Artificial Intelligence (AI), Machine Learning, Multithreading

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