CV

Filip Bielejec

Engineer-Scientist – bridging software engineering, applied cryptography and computational research

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About Me

Software engineer with over 10 years of professional experience. My background combines rigorous academic research (Google Scholar) with practical software development, giving me the ability to move seamlessly between abstract problem-solving and concrete system implementation.

I enjoy rapid prototyping, and in the recent years I have specialized in privacy-preserving zero-knowledge cryptography and blockchain infrastructure. I have hands-on experience across multiple blockchain ecosystems – Substrate, Ethereum, and EVM-compatible chains – building cross-chain platform systems, high-throughput async services, and open-source blockchain node contributions. I have a deep understanding of DeFi concepts such as automated market makers (AMMs), tokenomics, and MEV-prevention strategies.

Top Achievements

  • Developed Spread, an open-source platform for visualizing viral spread across time and geography, cited in research and actively used worldwide (example visualization). Engineering effort included JSON-based data format, animation engine, API, authentication system and storage layer – optimized for minimal costs and fast delivery (GitHub).

  • Designed and implemented the relayer component of the MOST Substrate–EVM Bridge, handling deterministic vs. probabilistic finality, deep reorgs, and building a “circuit breaker” failsafe for guardians (GitHub, commit).

  • Built a streamlined AMM-based decentralized exchange on Aleph Zero’s deterministic L1, showcased in the on-chain game The Button (code, blog post).

  • Co-developed Shielder, a Tornado Cash–like mixer with partial de-anonymization, enabling privacy with governance accountability. Implemented in-SNARK ElGamal encryption, Poseidon hash, and optimized Halo2 EC operations (GitHub, Poseidon, commit).

  • Active contributor to zero-knowledge cryptography research, experimenting with Arkworks, Halo2, Circom, and publishing open notes (ZK notes, study group).

  • Community engagement: co-organizer of the Leuven Functional Programming Meetup, technical blogger (blog.nodrama.io), and instructor for ink! smart contract development at the Polkadot Blockchain Academy.

Skills

   
Languages Rust (4 years), Clojure & ClojureScript (5 years), Python (2 years), Solidity (5 years), Java (2 years), R (3 years)
Blockchain Substrate, Ethereum/EVM, Aleph Zero, cross-chain bridges, smart contracts (ink!, Solidity)
DevOps AWS (CloudFront, EC2, Lambda, S3, CloudWatch), Docker, Kubernetes, GitHub Actions
Databases PostgreSQL, Firebase, Redis, Cassandra, ElasticSearch
Messaging Kafka, RabbitMQ, SQS
APIs REST, gRPC, GraphQL
Frameworks & Libraries REVM, Foundry, Halo2, Arkworks, Tokio, Substrate, ethers, Nvidia CUDA
Other CAS: Sage, Maxima. Typesetting: LaTeX. Literate programming: org-mode. Statistics & ML: R

Experience

Alongside Finance / Universal – Senior Engineer (2025 - present)

  • Developing AI-powered agentic compliance solutions for blockchain-based financial systems, leveraging LLMs, RAG pipelines, and autonomous agents
  • Building DeFi and fintech products at Universal, a platform for cross-chain digital asset management

Cardinal Cryptography – Senior Blockchain Engineer (2021 - 2025)

  • Designed and built the relayer for the MOST bridge, handling cross-chain communication between Substrate and Ethereum
  • Built The Button, an on-chain game demonstrating Aleph Zero’s fast finality
  • Co-implemented Halo2 circuits for the Shielder privacy protocol, enabling zk-SNARK-based confidential transactions
  • Contributed to the Rust implementation of Aleph Zero blockchain node based on the Substrate framework

Clash – Cofounder Engineer (2020 - 2021)

  • Designed and developed backend infrastructure for a mobile video-sharing social app
  • Researched architecture solutions and developed early prototypes
  • Built devops infrastructure, continuous delivery as well as client and backend services monitoring & alerting
  • Designed and implemented an AWS-based serverless S3 data lake and ingestion pipeline
  • Built a recommendation model using Rust, Spark, and TensorFlow
  • Co-developed much of the client code for the mobile application, leveraging ClojureScript compiled to ReactNative (blog post)

District0x – Senior Clojure Engineer (2017 - 2020)

LambdaWerk – Functional Software Engineer (2017)

  • Built healthcare data processing microservices with RabbitMQ messaging and REST APIs

Trimble T&L – Java Developer (2016 - 2017)

  • Developed logistics apps analyzing real-time truck telemetry data (CAN bus, GPS)
  • Migrated authentication and user management to Keycloak

KU Leuven, Rega Institute for Medical Research – Researcher (2011 - 2016)

  • Co-developed the BEAGLE high-performance computing library: massively parallel GPU-accelerated (NVIDIA CUDA) likelihood computations over large-scale genomic datasets
  • Built multi-dimensional statistical models for inferring heterogeneous evolutionary processes – published in Systematic Biology
  • Created SpreaD3, a spatiotemporal data visualization platform; still widely cited and used worldwide

Open Source Contributions

Year Project Description
2026 backoff Contributed to popular Rust exponential backoff crate (PR)
2025 datadog-tracing Upgraded Rust OpenTelemetry + Datadog integration to OpenTelemetry v0.31.x (PR)
2024 - 2025 MoonMath Manual Contributed fixes to open educational resource for understanding zk-SNARKs
2023 - 2024 Polkadot Blockchain Academy Authored ink! smart contract lecture materials and hands-on exercises (content, exercises)
2023 Poseidon377 Made Poseidon hash function WASM compatible for zero-knowledge systems (PR)
2022 cargo-contract Refactoring PR to official ink! WASM smart contract tooling (PR)
2021 load-test High-throughput Rust tool for API load testing
2020 rust-opencv OpenCV bindings and examples in Rust (14 stars)
2020 rust-tensorflow Running TensorFlow models from Rust for the recommendation engine talk
2019 cljs-firebase-client ClojureScript client library for Firebase (22 stars, blog post)
2017 - 2020 district0x IPFS client (GitHub), OrbitDB client (GitHub), Ethlance, MemeFactory, and core libraries
2018 - 2019 lein-solc Leiningen plugin for compiling Solidity smart contracts, with macro-preprocessor
2011 - 2016 BEAST / Beagle Widely-used Bayesian evolutionary analysis framework; co-developed the high-performance computing library

Education

  • 2025 – Zero Knowledge Proofs – Workshop on Zero Knowledge protocols, mainly Groth16
  • 2011 - 2015 – KU Leuven, Rega Institute for Medical Research – Doctoral Training in Bioinformatics
  • 2009 - 2010 – Ghent University – Master of Statistical Data Analysis Programme
  • 2005 - 2010 – Technical University of Lodz – Master in Mathematical Methods In Computer Science

Selected Publications & Talks

  • 2022 – SPREAD 4: online visualisation of pathogen phylogeographic reconstructions – Virus Evolution 8 (2)
  • 2021 – Making recommendations with Rust and Tensorflow – Virtual Lunch & Learn
  • 2019 – How to constrain your function inputs without the overhead of types? – Functional Programming Meetup, Leuven
  • 2013 – piBUSS: a parallel BEAST/BEAGLE utility for sequence simulation – BMC Bioinformatics 2014, 15:133
  • 2013 – Inferring large-scale heterogeneous evolutionary processes through time – Systematic Biology, Volume 63, Issue 4
  • 2012 – Massive parallelization of likelihood computations through graphics processing units – Bioinformatics Meeting, Leuven