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EXPLORE
4.0
4.0
86%
$20 USD / Hour
・
Poland (8:13 AM)
・
Joined on September 30, 2025
$20 USD / Hour
・
Full-stack and smart contract engineer with eight plus years building production web platforms and blockchain systems. Focus on Ethereum, L2 rollups, and React plus Node stacks for data heavy apps. Strong track record shipping secure contracts, reliable APIs, and clean frontends. Comfortable owning delivery across specs, tests, CI, and cloud. Freelancing since July 2025.
Verifications
On time
97%
On budget
97%
Accept rate
89%
Repeat hire rate
13%
Medicine Storefront
Laravel Admin for Inventory
Medicine Storefront
Medicine Storefront
Laravel Admin for Inventory
Medicine Storefront
Thank you, Kateryna. She has really good UI Emotion.
Vitalii D.
@vitaliid3
•
, Ukraine
•
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Kateryna is great blockchain smart contract engineer. She completed blockchain project for creating ERC-721/BEP-721 compliant NFT contracts that work seamlessly across Ethereum and Binance Smart Chain networks. She have also successfully implemented the SOL scanner upgrade to match the functionality of ETH, BSC, BASE, and POLYGON scanners. I highly recommend him for her passion and capabilities in blockchain. I will work with her again.
Former Client (inactive)
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She has amazing technology and experience in Blockchain. Perfect work in a shortest deadline. High recommended.
Oleksandr H.
@oleksandrg1
•
Chernivtsi, Ukraine
•
Share
Horrible experience. Did everything different as how I required it, and zero communications. I asked for hand coded php and css, no frame works. Still she started with frameworks, when I asked her to remove that, it turned out she could not work without that (she cannot hand code). She should have told me, instead of letting me hang for 3 weeks, due to which I almost lost my client. I finally gave up and hired another freelancer on here to start all over again.
Linda V.
@LindaVrh
•
Dijon, France
•
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Kateryna delivered exceptional quality and professionalism in developing the microservice for us. She finished ahead of schedule, producing clean, well-structured, and standards-compliant code that perfectly met our thecnical requirements. Exceeding expectations. She worked independently, with strong technical judgment, clear documentation, and excellent communication. Highly recommended. — a top-tier professional, reliable, and truly talented.
Felipe Antonio S.
@FelipeSaldias
•
Vitacuta, Chile
•
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Experience
Smart Contract Engineer
Mar, 2020 - Jun, 2025
•
5 years, 2 months
StarkWare Industries
Mar, 2020 - Jun, 2025
•
5 years, 2 months
Built Cairo and Solidity contracts for StarkNet. Optimized gas and call patterns, delivered SDK examples, and partner onboarding support. Stack used Cairo, Solidity, React, Node.
Tel Aviv, Israel
Mar, 2020 - Jun, 2025
•
5 years, 2 months
Full Stack Developer
Nov, 2019 - Feb, 2020
•
3 months
Trace Labs OriginTrail
Nov, 2019 - Feb, 2020
•
3 months
Contributed to Ethereum contracts and DKG data exchange. Built integrations for supply chain data ingestion with PostgreSQL. Stack used Node, PostgreSQL, Ethereum, OriginTrail protocol.
Ljubljana, Slovenia
Nov, 2019 - Feb, 2020
•
3 months
Backend and Blockchain Developer
Jan, 2019 - Oct, 2019
•
9 months
MIT Media Lab MedRec
Jan, 2019 - Oct, 2019
•
9 months
Implemented consent and access control smart contracts, built Node APIs for provider integration, and data security modules aligned with healthcare rules. Stack used React, Node, MongoDB, Solidity.
Cambridge, United States
Jan, 2019 - Oct, 2019
•
9 months
Education
Uniwersytet Zielonogórski
2015 - 2019
•
4 years
BSc Computer Science
Poland
2015 - 2019
•
4 years
Freelancer
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