Sergey Tolmachev (Tolsi) is a software architect and CTO with 12+ years building distributed systems, blockchain infrastructure, and early-stage products. Programming has been his greatest passion since childhood — the craft he loves more than anything else in life. In 2012 he built btcpay.ru — Russia's first Bitcoin-to-ruble exchange. At Waves Platform he was responsible for launching a public blockchain whose token reached a $5.61B peak market cap. Most recently at Blum — a Telegram-native exchange with 90M+ users — he was Lead of Analytics, building a realtime user-action analytics system at scale. He is open to CTO and tech lead engagements.
Work history —
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Blum — Lead of Analytics (2024–2025)
Telegram-native hybrid exchange backed by Binance Labs; 90M+ users. Built a realtime analytics system tracking user actions at large data volumes; drove data-driven product decisions across the platform.
Telegram-native hybrid exchange backed by Binance Labs; 90M+ users. Built a realtime analytics system tracking user actions at large data volumes; drove data-driven product decisions across the platform.
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Terra Support — Founder (2020–present)
SaaS platform for psychologists and coaches to run metaphorical associative card sessions remotely. Built end-to-end: auth, therapist dashboard, client tracking, custom deck builder, subscriptions. terra.support
SaaS platform for psychologists and coaches to run metaphorical associative card sessions remotely. Built end-to-end: auth, therapist dashboard, client tracking, custom deck builder, subscriptions. terra.support
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Waves Platform — R&D Lead (2017–2020)
Responsible for launching a public blockchain whose token reached a $3.25B peak market cap. Led R&D of core infrastructure: cross-chain atomic swaps, VRF-based verifiable randomness, Docker smart contracts (Python + face recognition on-chain), Ledger Nano hardware wallet app (C).
Responsible for launching a public blockchain whose token reached a $3.25B peak market cap. Led R&D of core infrastructure: cross-chain atomic swaps, VRF-based verifiable randomness, Docker smart contracts (Python + face recognition on-chain), Ledger Nano hardware wallet app (C).
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Waves Platform — Core Blockchain Node Developer (2016–2017)
Core node development on wavesplatform/Waves (open-source Scala). Implemented the leasing and lease-cancellation transaction type.
Core node development on wavesplatform/Waves (open-source Scala). Implemented the leasing and lease-cancellation transaction type.
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btcpay.ru — Founder (2012)
Russia's first Bitcoin-to-ruble exchange service, launched in 2012 — the same year BitPay reached its first 1,000 merchants globally. Built the full stack: protocol integration, fiat payment rails, anti-fraud, ops.
Russia's first Bitcoin-to-ruble exchange service, launched in 2012 — the same year BitPay reached its first 1,000 merchants globally. Built the full stack: protocol integration, fiat payment rails, anti-fraud, ops.
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Release.space — Co-founder (2023–2024)
Art space and cafe in Tbilisi. @release.tbilisi
Art space and cafe in Tbilisi. @release.tbilisi
Open source —
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atomic-swap-service — cross-chain atomic swaps between Waves and Bitcoin (Scala)
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waves-vrf-lottery — provably fair randomness via Waves block VRF signatures; used for a live public car giveaway (Lada Niva, 2019)
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face-recognition-contract — face recognition neural net deployed as a Docker smart contract on Vostok blockchain (Python + dlib)
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waves-arduino-candy-toy — ESP8266 vending machine accepting Waves blockchain payments (C++)
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aik — game AI library for Kotlin: A*, Dijkstra, 2D geometry engine
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op1dumps — reverse engineering the Teenage Engineering OP-1 synthesizer (Python, 15★)
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github.com/tolsi — 80 public repos · 198 followers · Arctic Code Vault Contributor
Public talks —
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Blum Chats #16 — "We Analyzed Everything — Here's What Our Users REALLY Do!" (2025, EN)
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Waves 3.0 Meetup — live cryptographically verified Niva car giveaway using VRF + blockchain randomness (2019, RU)
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BlockchainHack Moscow — masterclass to 25 competing teams + jury member (2018, RU)
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Pro Bitcoin Podcast ep. 48 (2017, RU)
Tech stack —
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Rust — threshold ECDSA, AI agent infrastructure
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Kotlin — game AI, pathfinding, 2D geometry
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Assembly (x86) — reverse engineering, OTUS coursework
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Also: Java, Ruby, SQL, JavaScript, Delphi, Lisp, PHP
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Blockchain: consensus (PoW/PoS/leasing), ECDSA, VRF, atomic swaps, smart contracts
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Distributed systems: event streaming (CDC/Kafka), distributed databases
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AI/ML: face recognition on-chain, AI agent infrastructure
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Architecture: software design, R&D, prototyping, deployment, DevOps
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Analytics: realtime data pipelines, large-scale user event tracking, product analytics