
Jordan Millar engineered robust Cardano blockchain tooling across the IntersectMBO/cardano-cli and IntersectMBO/cardano-api repositories, focusing on era-aware scripting, governance, and transaction workflows. He developed unified APIs for certificate and script handling, implemented flexible Plutus and simple script ingestion, and enhanced transaction construction with new data structures and fee estimation logic. Using Haskell and CBOR serialization, Jordan refactored command-line interfaces for maintainability, parameterized commands for multi-era compatibility, and improved error handling and test coverage. His work addressed cross-era integration challenges, streamlined developer onboarding, and ensured reliable, maintainable codebases that support evolving Cardano ledger features and business requirements.

February 2026: Focused on expanding Cardano tooling capabilities and aligning API metadata. Delivered a flexible script decoding feature for cardano-cli and updated the copyright year in cardano-api, enhancing developer productivity and compliance. No major defects fixed this month; work prioritized business value and long-term maintenance.
February 2026: Focused on expanding Cardano tooling capabilities and aligning API metadata. Delivered a flexible script decoding feature for cardano-cli and updated the copyright year in cardano-api, enhancing developer productivity and compliance. No major defects fixed this month; work prioritized business value and long-term maintenance.
January 2026 monthly summary focused on delivering cohesive scripting capabilities, API enhancements, and reliability improvements across Cardano-related repositories, with a strong emphasis on business value, user-facing safety, and multi-ledger readiness.
January 2026 monthly summary focused on delivering cohesive scripting capabilities, API enhancements, and reliability improvements across Cardano-related repositories, with a strong emphasis on business value, user-facing safety, and multi-ledger readiness.
December 2025 monthly summary focusing on delivering maintainable code, reliable testnet/CI operations, and robust data serialization. Cross-repo work across IntersectMBO/cardano-node and IntersectMBO/cardano-api improved maintainability, reliability, and data integrity, with tangible business value through reduced risk and faster iteration.
December 2025 monthly summary focusing on delivering maintainable code, reliable testnet/CI operations, and robust data serialization. Cross-repo work across IntersectMBO/cardano-node and IntersectMBO/cardano-api improved maintainability, reliability, and data integrity, with tangible business value through reduced risk and faster iteration.
Monthly summary for 2025-11: Delivered production-ready enhancements across the Cardano suite with a focus on reliability, maintainability, and business value. Key outcomes include generalizing testnet monadic contexts and improving IO handling across IntersectMBO/cardano-node, robust error handling for absent testnet sprockets, governance and certificate handling overhaul in IntersectMBO/cardano-cli with updated data structures and new workflows, a refactored transaction construction workflow using makeUnsignedTx, and an upgrade of the Cardano API ecosystem (cardano-api and related packages) including UnsignedTx modularization and a new TxBodyContent. These efforts improve deployment confidence, reduce maintenance toil, and broaden integration and testing coverage.
Monthly summary for 2025-11: Delivered production-ready enhancements across the Cardano suite with a focus on reliability, maintainability, and business value. Key outcomes include generalizing testnet monadic contexts and improving IO handling across IntersectMBO/cardano-node, robust error handling for absent testnet sprockets, governance and certificate handling overhaul in IntersectMBO/cardano-cli with updated data structures and new workflows, a refactored transaction construction workflow using makeUnsignedTx, and an upgrade of the Cardano API ecosystem (cardano-api and related packages) including UnsignedTx modularization and a new TxBodyContent. These efforts improve deployment confidence, reduce maintenance toil, and broaden integration and testing coverage.
October 2025 monthly summary focusing on delivering business value through robust API capabilities, improved testnet tooling, and resilient lifecycle management across Cardano API and Node repos. Highlights include era-aware certificate handling, staking workflow enhancements, streamlined testnet provisioning, and robust asynchronous lifecycle management. These efforts reduce deployment risk, accelerate validation cycles, and enable staking features at scale.
October 2025 monthly summary focusing on delivering business value through robust API capabilities, improved testnet tooling, and resilient lifecycle management across Cardano API and Node repos. Highlights include era-aware certificate handling, staking workflow enhancements, streamlined testnet provisioning, and robust asynchronous lifecycle management. These efforts reduce deployment risk, accelerate validation cycles, and enable staking features at scale.
September 2025 monthly summary focusing on key accomplishments, with emphasis on business value and cross-era capabilities across Cardano API and CLI.
September 2025 monthly summary focusing on key accomplishments, with emphasis on business value and cross-era capabilities across Cardano API and CLI.
In August 2025, delivered significant enhancements across IntersectMBO/cardano-api and IntersectMBO/cardano-cli, focusing on compatibility, reliability, and test coverage. Key outcomes include bug fix in ledger CDDL key witness CBOR deserialization, exposure of critical ledger functionality, backward-compatibility improvements for genesis flag handling, and robust validation tests for Alonzo-era cost models. These changes reduce integration risk with Ledger specs and support multi-era genesis workflows, while expanding developer surface area through re-exported ledger APIs and improved environment handling.
In August 2025, delivered significant enhancements across IntersectMBO/cardano-api and IntersectMBO/cardano-cli, focusing on compatibility, reliability, and test coverage. Key outcomes include bug fix in ledger CDDL key witness CBOR deserialization, exposure of critical ledger functionality, backward-compatibility improvements for genesis flag handling, and robust validation tests for Alonzo-era cost models. These changes reduce integration risk with Ledger specs and support multi-era genesis workflows, while expanding developer surface area through re-exported ledger APIs and improved environment handling.
July 2025 performance summary: Delivered major feature releases and stability improvements across Cardano tooling, with a strong emphasis on era-aware CLI behavior, improved release processes, and code health. Key outcomes include a new Cardano API release (10.17.2.0) with WASM/JS wrappers and a new estimateBalancedTxBody API; extensive era-based parameterization and CIO-based IO handling across the cardano-cli command suite; enhanced Node hotfix release documentation; and ongoing code quality improvements and version tracking.
July 2025 performance summary: Delivered major feature releases and stability improvements across Cardano tooling, with a strong emphasis on era-aware CLI behavior, improved release processes, and code health. Key outcomes include a new Cardano API release (10.17.2.0) with WASM/JS wrappers and a new estimateBalancedTxBody API; extensive era-based parameterization and CIO-based IO handling across the cardano-cli command suite; enhanced Node hotfix release documentation; and ongoing code quality improvements and version tracking.
June 2025 performance summary across three repositories (tweag/hoarding-cardano-node, IntersectMBO/cardano-cli, IntersectMBO/cardano-api). Delivered network dependency updates, era-aware scripting and certificate handling, and strategic refactors to improve maintainability, test stability, and cross-era interoperability. Implemented ScriptRequirements support to unify script ingestion, modernized certificate script witness IO with a compatibility layer, and extended era-specific constraints with a general Certificate type to broaden transaction processing capabilities. Completed extensive test fixes and cleanup, enabling more reliable CI and faster iteration on new Cardano eras. Demonstrated strong technical breadth across Haskell/Plutus tooling, Cardano era abstractions, and ecosystem integration. Business value includes reduced risk from network upgrades, improved tooling reliability, and faster onboarding of era-specific features.
June 2025 performance summary across three repositories (tweag/hoarding-cardano-node, IntersectMBO/cardano-cli, IntersectMBO/cardano-api). Delivered network dependency updates, era-aware scripting and certificate handling, and strategic refactors to improve maintainability, test stability, and cross-era interoperability. Implemented ScriptRequirements support to unify script ingestion, modernized certificate script witness IO with a compatibility layer, and extended era-specific constraints with a general Certificate type to broaden transaction processing capabilities. Completed extensive test fixes and cleanup, enabling more reliable CI and faster iteration on new Cardano eras. Demonstrated strong technical breadth across Haskell/Plutus tooling, Cardano era abstractions, and ecosystem integration. Business value includes reduced risk from network upgrades, improved tooling reliability, and faster onboarding of era-specific features.
May 2025 monthly summary focusing on delivering era-aware command infrastructure, CIO-based IO refactors, and release/workflow improvements across Cardano CLI tooling. Highlights include era-parameterization, modernized command execution paths, governance and treasury command improvements, and targeted build/maintenance cleanup that reduce technical debt and accelerate future upgrades.
May 2025 monthly summary focusing on delivering era-aware command infrastructure, CIO-based IO refactors, and release/workflow improvements across Cardano CLI tooling. Highlights include era-parameterization, modernized command execution paths, governance and treasury command improvements, and targeted build/maintenance cleanup that reduce technical debt and accelerate future upgrades.
April 2025 delivered API, CLI, and tooling enhancements across Cardano-related repositories, with a focus on correctness of transaction witnesses, API ergonomics, and release traceability. Key features include redeemer pointer map integrity fixes, improved ToAnyWitness handling for simple scripts, API maintenance with era/type-level enhancements, CIP-129 CLI support, and version metadata tracking across packages.
April 2025 delivered API, CLI, and tooling enhancements across Cardano-related repositories, with a focus on correctness of transaction witnesses, API ergonomics, and release traceability. Key features include redeemer pointer map integrity fixes, improved ToAnyWitness handling for simple scripts, API maintenance with era/type-level enhancements, CIP-129 CLI support, and version metadata tracking across packages.
March 2025 performance summary: Delivered core Plutus script witness infrastructure and API enhancements, extended stake pool key support, and era-aware inputSet typing in tweag/cardano-api-forked; added CIP-129 governance serialization in IntersectMBO/cardano-api. These efforts improved script data handling during transaction construction and fee calculation, ensured consistent key management across extended stake pools, and strengthened cross-era type safety. Overall, the work enhances reliability, maintainability, and cross-repo governance data integrity, delivering tangible business value in blockchain transaction workflows and governance tooling.
March 2025 performance summary: Delivered core Plutus script witness infrastructure and API enhancements, extended stake pool key support, and era-aware inputSet typing in tweag/cardano-api-forked; added CIP-129 governance serialization in IntersectMBO/cardano-api. These efforts improved script data handling during transaction construction and fee calculation, ensured consistent key management across extended stake pools, and strengthened cross-era type safety. Overall, the work enhances reliability, maintainability, and cross-repo governance data integrity, delivering tangible business value in blockchain transaction workflows and governance tooling.
February 2025 monthly summary focusing on delivering robust, cross-era scripting capabilities in Cardano tooling, with a strong emphasis on business value and reliability. Key features delivered include: (1) Proposal Script Handling in Cardano CLI, introducing new modules and types (Cardano.CLI.EraBased.Script.Proposal.Types and Cardano.CLI.EraBased.Script.Proposal.Read) and robust parsing for proposal, simple, Plutus, and reference script witnesses, replacing ScriptWitnessFiles usage; (2) Withdrawal Script Handling, adding module support to read withdrawal script witnesses and propagate withdrawal script requirements through CLI and transaction building; (3) CLI Error Handling, Refactor, and Cleanup, migrating to the RIO monad, introducing new exception types, and improving command execution, help/encoding outputs, and error surfaces; (4) Internal Refactor of BuildTxWith, moving it to Cardano.Api.Internal.Tx.BuildTxWith to resolve cyclic dependencies and improve modularity; (5) Plutus/Script handling overhaul in the forked repo, introducing in-era types for scripts and witnesses (AnyWitness era, SimpleScript era, PlutusScriptInEra lang era, PlutusScriptWitness lang era) and earlier error surfacing; (6) Stake key deserialization into verification key envelopes and governance-type equality support across eras. Overall impact is improved reliability, faster development cycles for script-based transactions, safer cross-era interactions, and clearer error feedback for developers and operators.
February 2025 monthly summary focusing on delivering robust, cross-era scripting capabilities in Cardano tooling, with a strong emphasis on business value and reliability. Key features delivered include: (1) Proposal Script Handling in Cardano CLI, introducing new modules and types (Cardano.CLI.EraBased.Script.Proposal.Types and Cardano.CLI.EraBased.Script.Proposal.Read) and robust parsing for proposal, simple, Plutus, and reference script witnesses, replacing ScriptWitnessFiles usage; (2) Withdrawal Script Handling, adding module support to read withdrawal script witnesses and propagate withdrawal script requirements through CLI and transaction building; (3) CLI Error Handling, Refactor, and Cleanup, migrating to the RIO monad, introducing new exception types, and improving command execution, help/encoding outputs, and error surfaces; (4) Internal Refactor of BuildTxWith, moving it to Cardano.Api.Internal.Tx.BuildTxWith to resolve cyclic dependencies and improve modularity; (5) Plutus/Script handling overhaul in the forked repo, introducing in-era types for scripts and witnesses (AnyWitness era, SimpleScript era, PlutusScriptInEra lang era, PlutusScriptWitness lang era) and earlier error surfacing; (6) Stake key deserialization into verification key envelopes and governance-type equality support across eras. Overall impact is improved reliability, faster development cycles for script-based transactions, safer cross-era interactions, and clearer error feedback for developers and operators.
January 2025: Delivered substantial improvements to Plutus script handling and script-driven workflows across Cardano CLI, resulting in safer decoding, expanded script support for certificates and governance, and centralized parsing/reading logic. These changes reduce transaction risk, improve automation, and accelerate feature delivery while strengthening type-safety and test coverage.
January 2025: Delivered substantial improvements to Plutus script handling and script-driven workflows across Cardano CLI, resulting in safer decoding, expanded script support for certificates and governance, and centralized parsing/reading logic. These changes reduce transaction risk, improve automation, and accelerate feature delivery while strengthening type-safety and test coverage.
December 2024 focused on enhancing the cardano-cli query utxo flow with binary CBOR output and expanded test coverage. Delivered a binary CBOR output option for the utxo query and updated golden tests to validate the new option across network versions. This improves automation, cross-version compatibility, and overall reliability of UTXO queries.
December 2024 focused on enhancing the cardano-cli query utxo flow with binary CBOR output and expanded test coverage. Delivered a binary CBOR output option for the utxo query and updated golden tests to validate the new option across network versions. This improves automation, cross-version compatibility, and overall reliability of UTXO queries.
November 2024 performance summary focusing on delivering robust features and reliable tooling across three Cardano-related repos. Key outcomes include optimized datum lookup, enhanced Plutus scripting error reporting and era-conversion clarity, Windows-friendly golden tests, and a major minting script refactor to support era-based workflows. These changes improve robustness, safety, and developer productivity while strengthening end-to-end transaction pipelines.
November 2024 performance summary focusing on delivering robust features and reliable tooling across three Cardano-related repos. Key outcomes include optimized datum lookup, enhanced Plutus scripting error reporting and era-conversion clarity, Windows-friendly golden tests, and a major minting script refactor to support era-based workflows. These changes improve robustness, safety, and developer productivity while strengthening end-to-end transaction pipelines.
October 2024 performance window focused on strengthening test coverage for Plutus datum handling and stabilizing the Cardano CLI workflow to improve reliability and developer efficiency. Delivered targeted features in two repositories with clear business impact: enhanced validation of datum presence in Plutus V3 tests and stabilized CLI query operations with updated tooling and documentation. The work emphasizes measurable improvements in test coverage, reproducibility, and onboarding efficiency for engineers. Key outcomes include tighter test assertions around datum handling, and a more reliable and observable CLI surface for querying blockchain state, underpinned by updated golden files and docs.
October 2024 performance window focused on strengthening test coverage for Plutus datum handling and stabilizing the Cardano CLI workflow to improve reliability and developer efficiency. Delivered targeted features in two repositories with clear business impact: enhanced validation of datum presence in Plutus V3 tests and stabilized CLI query operations with updated tooling and documentation. The work emphasizes measurable improvements in test coverage, reproducibility, and onboarding efficiency for engineers. Key outcomes include tighter test assertions around datum handling, and a more reliable and observable CLI surface for querying blockchain state, underpinned by updated golden files and docs.
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