Senior Blockchain Engineer · Poland · Global B2B

Custody infrastructure for systems that hold real money.

I design and build the backend paths that hold and move digital assets: key management, signing, transaction lifecycle, reconciliation and multi-chain integrations for startups and regulated financial institutions.

Seven-plus years across blockchain, fintech and enterprise backends. Bitcoin, EVM, Solana and permissioned networks.

View services Discuss a project

Selected work

Bank tokenization platform: Architected seven-plus Java and Spring Boot services covering token operations, payments, scheduling and reconciliation with a bank core system. Delivered live migrations on a running platform with zero post-merge production regressions.
Solana token infrastructure: Built Token-2022 flows, Meteora liquidity, Jupiter swaps, Squads Multisig V4 governance and GCP KMS-backed signing as one end-to-end operating path.
Enterprise DLT networks: Delivered permissioned financial networks with Hyperledger Besu, GoQuorum, Canton/Daml, FireFly and Kaleido across Terraform-managed environments.
WORK token launch: Led development of the WORK token at Paidwork, reducing transaction costs by 99% for a 17-million-user platform through L2 rollups. The contract was publicly audited. CoinMarketCap · audit
Euro stablecoin supply monitor: A public page that reads the on-chain totalSupply of six euro e-money tokens on Ethereum every day and shows it next to each issuer's own reserve statement, quoted verbatim with source. It shows facts and quotes and gives no verdicts. Open the monitor

What I work on

Custody and wallets: KMS/HSM signing, multisig and MPC coordination, policy engines, deposit detection, transaction state machines, reorg handling and ledger reconciliation.
Multi-chain systems: Bitcoin and UTXO semantics, EVM and account abstraction, Solana programs and token accounts, without forcing one chain's model onto another.
Fintech backend: Java/Spring Boot and TypeScript/NestJS microservices, event-driven systems, PostgreSQL ledgers and high-integrity transactional workflows.
AI-assisted delivery: Agent workflows, MCP servers and review automation with deterministic guardrails, explicit evidence and human accountability for the final result.

Writing

Field notes from systems where a missed edge case can move money, corrupt a ledger or produce evidence nobody can reproduce.

Instant Settlement Is a Funding DecisionOct 2026
The Registrar Should Not Know the PriceOct 2026
Reproducible Supply Evidence for Euro E-Money TokensSep 2026
AI Coding Agents in Production: What Actually ChangesAug 2026
SIGHASH Is a Security Parameter, Not a Construction DetailAug 2026
Balance at 14:00 UTC Does Not ExistAug 2026

Working stack

BlockchainSolana, Rust, Anchor, Solidity, Besu, GoQuorum, Canton/Daml

BackendJava, Spring Boot, TypeScript, NestJS, Node, Python

DataPostgreSQL, RabbitMQ, Redis, Liquibase, IPFS

DeliveryAWS, GCP, Kubernetes, Terraform, Docker, ArgoCD, Helm

Background

Software house co-founder: Co-founded and ran a 15-developer software house across architecture, delivery, budgeting and client relationships.
Education: B.Eng. in Computer Science, Artificial Intelligence specialization, GPA 5.0. Certified Ethereum Expert and Certified Ethereum Developer.

Need a custody system, lending market or vault reviewed?

See engagements, write to [email protected] or reach me on LinkedIn.