Stefan Batalka, Developer in London, United Kingdom
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Stefan Batalka

Verified Expert  in Engineering

Blockchain Developer

London, United Kingdom
Toptal Member Since
October 11, 2022

Stefan is a distributed ledger technology expert with a background in financial applications and deploying algorithmic trading models on centralized exchanges. Since the advent of decentralized finance, his focus has shifted to on-chain trading and maximal extractable value (MEV), particularly in the Ethereum ecosystem. Stefan is comfortable with the Ethereum virtual machine (EVM) networking stack, including core protocol details, node codebases, Solidity, and smart contract development.


Solidity, Solidity Assembly, Earned Value Management (EVM), Business Ideas...
Ranvier Group
Python, Rust, Go, JavaScript, TypeScript, Dart, Flutter, React, Next.js, Pandas...
JavaScript, TypeScript, React, Next.js, APIs, Ethereum, Ethers.js, Web3.js...




Preferred Environment

Foundry, Python, Rust, MetaMask, Algorithmic Trading, Blockchain

The most amazing...

...project I've developed is a low-latency, high-performance blockchain infrastructure which outperforms any available alternative.

Work Experience

Core Advisor

2022 - PRESENT
  • Advised founders regarding project implementation and development across the product lifecycle, from inception to deployment.
  • Reviewed and audited critical smart contract code.
  • Optimized tokenomics and marketing strategies to best align with the project aim.
  • Designed and developed a novel market-making strategy for decentralized exchanges.
Technologies: Solidity, Solidity Assembly, Earned Value Management (EVM), Business Ideas, Business Models, Finance, Architecture, ERC-20

Chief Technology Officer (CTO)

2016 - PRESENT
Ranvier Group
  • Led the development of low-latency, high-performance blockchain infrastructure.
  • Developed interfaces and performed the execution against node infrastructure.
  • Worked with the project founders to best realize conceptual blockchain ideas.
  • Wrote Solidity smart contracts, technical documentation, and whitepapers.
  • Executed strategies, capturing value from on-chain opportunities.
  • Advised teams, implementing statistical arbitrage and market making.
  • Created and deployed directional systematic trading strategies for the cryptocurrency market.
Technologies: Python, Rust, Go, JavaScript, TypeScript, Dart, Flutter, React, Next.js, Pandas, NumPy, Scikit-learn, WebSockets, Multiprocessing, Asyncio, IPFS, Blockchain, Smart Contracts, Non-fungible Tokens (NFT), ERC-20

Decentralized Application Engineering Lead

2020 - 2022
  • Designed decentralized application project architecture.
  • Authored technical whitepapers, ensuring the implementation.
  • Developed and deployed Solidity smart contracts for on-chain execution.
Technologies: JavaScript, TypeScript, React, Next.js, APIs, Ethereum, Ethers.js, Web3.js, White Papers, Design, ERC-20

Full-stack Engineering Lead

2020 - 2022
FIFO Finance
  • Guided project development from inception to launch.
  • Extended internally developed infrastructure to create an application programming interface (API) for projects to use without compromising performance.
  • Developed a decentralized, permissionless system for the on-chain trading activity that is securely routed by a third-party system.
  • Implemented scalable low-latency execution for retail users.
Technologies: APIs, Service, Software, SaaS, Ethereum, Ethereum Smart Contracts, Distributed Systems, Distributed Software, ERC-20

Technical Lead

2020 - 2021
  • Worked with the founding team to design technical solutions that effectively implemented the conceptual idea.
  • Architected a fully functional multichain application with cutting-edge, competitive cross-chain bridging.
  • Authored a technical whitepaper outlining the protocol.
  • Developed and deployed novel Solidity smart contract implementations.
Technologies: Solidity, Solidity Assembly, ERC-20

Lingo is the first compounding token that leverages blockchain technology and real estate collateral to reward its community with monthly vacation airdrops.

People picture Web3 as risky. Unlike most tokens, Lingo is cushioned by real estate assets. On top of providing real value, real estate has been one of the safest hedges against inflation and volatility.

Unlike most tokens, Lingo is easy to understand—it's a token that sends people on vacation in real life. Lingo airdrops vacations across thousands of hotels worldwide every month to Lingo holders.

FIFO Finance

FIFO stands for First In, First Out. The system ensures that the user is one of the first to act, regardless of buying, selling, or any other interaction.

Most systems on the market rely on users to provide their network nodes or rely on publicly available node infrastructure. We have created our system from scratch, with an uncompromising focus on performance and reduction in latency specifically for the task of high-frequency executions on-chain, including detecting and broadcasting transactions, as well as on-chain execution simulation.

Funds are deposited and held in a smart contract on-chain. Users decide what permissions they want that contract to have, such as purchasing a specific token and sending it to their wallet.

OSOK Finance

OSOK is a blazing-fast token sniper that ensures users reliably receive tokens, at the best possible price, immediately after launch on decentralized or centralized exchanges. A set of on-chain smart contracts with limited permissions lets the OSOK team maintain proprietary execution infrastructure and limit the use of users' funds strictly to the approved token purchase.

Rust-based Ethereum Node (RubEN)
A proprietary internally developed Rust node infrastructure for EVM blockchains. By removing much of the overhead associated with the original public node implementation, RubEN can quickly identify, simulate and broadcast transactions across EVM networks, providing fast, reliable execution for on- and cross-chain interactions and opening up for more complex algorithmic trading strategies.


React, Web3.js, Pandas, NumPy, Scikit-learn, Asyncio




Truffle, Hardhat, Flutter, Next.js


Ethereum, Blockchain


Python, Solidity, Solidity Assembly, JavaScript, Rust, TypeScript, Go, Dart


Earned Value Management (EVM), Ethereum Smart Contracts, Algorithmic Trading, Systematic Trading, Decentralized Systems, Smart Contracts, Non-fungible Tokens (NFT), ERC-20, Foundry, IPFS, libp2p, Business Ideas, Business Models, Finance, Architecture, APIs, Service, Software, SaaS, Distributed Systems, Distributed Software, Ethers.js, WebSockets, Multiprocessing, White Papers, Design

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