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Andrzej Broński

Senior Software Engineer

Developer with 4+ years of professional Rust experience – fascinated by crypto and building fast, reliable systems.
Make it work • Make it right • Make it fast
Kraków, Poland (UTC+2)

Proof of excellence

Experience

Malda.xyz
Lead ZK Engineer
Dec 2025
May 2026
Budapest, Hungary · Remote
Shut down · Apr 2026 (no PMF)
  • Took ownership of a ZK-based cross-chain sequencer project, driving it to mainnet readiness.
Key results:
  • Introduced full zkVM guest reproducibility by nixifying Risc0 – malda/risc0pkgs.
  • Dockerized RPC infrastructure for Ethereum, Linea, Base, and Optimism – malda/atlas.
  • Implemented Linea block verifier for their new consensus model – malda/linea-header-verifier.
  • Established full CI pipeline for the Malda coprocessor codebase: format checks, linting, tests, and reproducible builds.
Gevulot / ZkCloud
Senior Software Engineer
Aug 2024
Nov 2025
Helsinki, Finland · Remote
Dropped ZK proving · pivoted to Zenith (Canton)
  • Benchmarking and integrating external ZK provers; writing custom orchestration.
  • Working on Ethereum real-time proving.
Key results:
  • In the first month, won “Aztec Decentralization Contest”, in both categories (US $20,000).
  • Eliminated a bottleneck in Ethereum proving: reduced input preparation from ~4 minutes to 2 seconds, and open sourced solution.
  • Achieved Ethereum real-time proving with a cluster of 48× RTX 4090 and ZisK zkVM, live-tested at Devconnect Argentina (Nov 2025).
Casper Network
R&D Engineer
Jan 2023
Jul 2024
Zug, Switzerland · Remote
No traction · token down >95% since 2023
  • Building a dedicated L2 for processing payments, using zero-knowledge technology.
  • Assessing grant deliverables.
  • Representing the company at public events.
Key results:
  • Designed L2 system ‘Kairos’ and implemented its core parts: ASN.1-based schema, cryptography, L1 synchronization.
  • Created blockchain library for handling events: Casper Event Toolkit.
  • Reviewed 30+ grant projects and recommended cancellation for many due to grant farming.
  • Performed public speeches: ~ ‘Web3 vs Web2 development’ – Lubelskie Dni Informatyki, university at Lublin. ~ ‘How to quickly start building on Casper?’ – Cryptosphere conference in Wrocław. ~ ‘Dynamic NFTs’ – Web3 Berlin conference.
Next on p. 2 ⟶ JumpWire, Founding Engineer
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Profile Photo
Andrzej Broński

Senior Software Engineer

Developer with 4+ years of professional Rust experience – fascinated by crypto and building fast, reliable systems.
Make it work • Make it right • Make it fast
Kraków, Poland (UTC+2)

Experience (continued)

JumpWire (YC W22)
Founding Engineer
Jun 2022
Nov 2022
Boston, MA, US · Remote
Acquired by WorkOS · Jan 2024
  • Building MVP – platform for dynamic data access control.
Key results:
  • Implemented REST proxy, configurable via OpenAPI specification file.
  • Fixed binary protocol bug, where type was incorrectly converted.
  • Implemented rediscovery of DB schema, handling potential conflicts.
Microsoft Ireland
Software Engineer II
Aug 2021
Nov 2021
Dublin, Ireland · Hybrid
  • Enhancing security of Azure Cloud infrastructure.
  • Creating new security monitors, using C# and KQL.
Key results:
  • Analyzed and documented 50+ security rules; gathered knowledge from 3 different teams.
  • Fixed silent-failure defects in ~20 monitors.
  • Introduced health-check dashboard; discovered several repeatedly failing monitors.
ESET Polska
Specialized Software Engineer
Nov 2019
Jul 2021
Kraków, Poland · On-site
  • Developing a new platform for fuzz-testing antivirus modules.
Key results:
  • Developed cross-platform worker node in C++.
  • Created REST fuzzing service for Endpoint product – on the first run it found +10 unique crashes.
  • Adjusted PDF module to cross-compile with ASan – discovered 2 memory bugs.
Securitum
Penetration Tester
Sep 2017
Sep 2018
Kraków, Poland · On-site
  • White-hat hacking web and mobile applications.
  • Static code analysis.
  • Writing security reports in accordance with OWASP ASVS framework.
Key results:
  • Won “bug of the month” prize, for exploiting Java deserialization bug – full RCE, even before client prepared test account.
  • Found critical vulnerability in a major Polish bank.
  • Wrote Java Deobfuscator for ZKM 5 – used to extract app secret key.
Freelancing
Web Developer
2014 – 2017 · Dec 2021
May 2022
Nowy Sącz / Kraków, Poland · Remote
  • Creating full-stack web projects, either for individual clients or for contracting company.

Education

AGH University of Science and Technology
Kraków, Poland
Jan 2019 – Dec 2020
Master’s degree in Computer Science
Autoscaling of computations in container clouds.
AGH University of Science and Technology
Kraków, Poland
Oct 2015 – Jan 2019
Bachelor’s degree in Computer Science
Modern web applications penetration testing.
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