hiero-ledger/hiero-mirror-node
Nov 2024 – Oct 2025
12 Months active
Languages Used
JavaJavaScriptKotlinShellGherkinGradleMarkdownYAML
Technical Skills
API DevelopmentBackend DevelopmentBuild AutomationCI/CDCode FormattingNode.js
Stoyan Dimitrov
PROFILE
Stoyan Dimitrov
Stoyan Dimitrov engineered backend features and reliability improvements for the hiero-ledger/hiero-mirror-node repository over twelve months, focusing on API development, database optimization, and system resilience. He implemented modular transaction execution, dynamic API exposure controls, and robust caching strategies using Java and Spring Boot, addressing performance bottlenecks and reducing operational risk. Stoyan enhanced contract state retrieval by batching and caching queries, introduced feature flags for secure endpoint management, and optimized SQL queries for token operations. His work included rigorous testing, concurrency fixes, and CI/CD stabilization, resulting in maintainable, scalable code that improved deployment confidence and data integrity across Hedera network environments.
Overall Statistics
Feature vs Bugs
63%Features
Repository Contributions
46Total
Bugs
10
Commits
46
Features
17
Lines of code
11,782
Activity Months12
Your Network
47 people
Work History
October 2025
2 Commits • 1 Features
Oct 1, 2025Month: 2025-10. Focused on reliability and performance improvements for system accounts in hiero-mirror-node. Key work centered on robust handling of historical contract calls and reducing database load via caching, delivering more stable data paths and faster retrieval for small system accounts.
2 Commits • 1 Features
Oct 1, 2025Month: 2025-10. Focused on reliability and performance improvements for system accounts in hiero-mirror-node. Key work centered on robust handling of historical contract calls and reducing database load via caching, delivering more stable data paths and faster retrieval for small system accounts.
October 2025
September 2025
2 Commits • 2 Features
Sep 1, 2025September 2025 monthly summary for hiero-mirror-node focused on delivering robust API capabilities and improving developer experience. Key work concentrated on token/NFT access enhancements, REST API pagination, and token name lookup to improve data discoverability and integration reliability.
September 2025
2 Commits • 2 Features
Sep 1, 2025September 2025 monthly summary for hiero-mirror-node focused on delivering robust API capabilities and improving developer experience. Key work concentrated on token/NFT access enhancements, REST API pagination, and token name lookup to improve data discoverability and integration reliability.
August 2025
4 Commits • 2 Features
Aug 1, 2025Summary for 2025-08 (hiero-ledger/hiero-mirror-node): Delivered targeted improvements to API exposure control, startup performance, and transaction safety, alongside reinforced robustness tests. Implemented a feature-flag mechanism to gate API endpoints via ingress with a fallback to the original JavaScript API for unavailable endpoints, and introduced ApplicationWarmup to proactively preload web3 resources during Kubernetes readiness probes. Fixed a critical concurrency issue in the transaction execution path by synchronizing the factory create method, and expanded importer robustness with tests validating error handling for out-of-order blocks. The combined work enhances reliability, reduces startup latency, and strengthens data integrity in production deployments.
4 Commits • 2 Features
Aug 1, 2025Summary for 2025-08 (hiero-ledger/hiero-mirror-node): Delivered targeted improvements to API exposure control, startup performance, and transaction safety, alongside reinforced robustness tests. Implemented a feature-flag mechanism to gate API endpoints via ingress with a fallback to the original JavaScript API for unavailable endpoints, and introduced ApplicationWarmup to proactively preload web3 resources during Kubernetes readiness probes. Fixed a critical concurrency issue in the transaction execution path by synchronizing the factory create method, and expanded importer robustness with tests validating error handling for out-of-order blocks. The combined work enhances reliability, reduces startup latency, and strengthens data integrity in production deployments.
August 2025
July 2025
1 Commits • 1 Features
Jul 1, 2025Month 2025-07: Delivered a robust database rollback capability for hiero-mirror-node via a drop.sql script to reset database state for safe version rollbacks. The script drops tables, views, materialized views, types, functions, procedures, and the mirror_api role; includes validation that the importer can recover data after applying the script, and was tested in a local Kubernetes cluster against Citus. This work reduces deployment risk and enables safer, faster rollbacks across environments.
July 2025
1 Commits • 1 Features
Jul 1, 2025Month 2025-07: Delivered a robust database rollback capability for hiero-mirror-node via a drop.sql script to reset database state for safe version rollbacks. The script drops tables, views, materialized views, types, functions, procedures, and the mirror_api role; includes validation that the importer can recover data after applying the script, and was tested in a local Kubernetes cluster against Citus. This work reduces deployment risk and enables safer, faster rollbacks across environments.
June 2025
1 Commits • 1 Features
Jun 1, 2025June 2025 performance-focused sprint for hiero-mirror-node. Delivered a feature that significantly accelerates contract state retrieval by batching and caching contract slots, reducing unnecessary pre-loading and prioritizing recently queried slots. Implemented in the hiero-ledger/hiero-mirror-node codebase with a dedicated change to minimize storage query overhead and improve responsiveness for contract state lookups.
1 Commits • 1 Features
Jun 1, 2025June 2025 performance-focused sprint for hiero-mirror-node. Delivered a feature that significantly accelerates contract state retrieval by batching and caching contract slots, reducing unnecessary pre-loading and prioritizing recently queried slots. Implemented in the hiero-ledger/hiero-mirror-node codebase with a dedicated change to minimize storage query overhead and improve responsiveness for contract state lookups.
June 2025
May 2025
2 Commits • 1 Features
May 1, 2025May 2025 (2025-05) performance and reliability focus for hiero-ledger/hiero-mirror-node. Delivered a caching and test-stability upgrade set that reduces DB load, improves latency under burst traffic, and strengthens test reliability across EVM version changes. These efforts collectively enhanced throughput, reduced operational risk, and accelerated feedback cycles for production workloads.
May 2025
2 Commits • 1 Features
May 1, 2025May 2025 (2025-05) performance and reliability focus for hiero-ledger/hiero-mirror-node. Delivered a caching and test-stability upgrade set that reduces DB load, improves latency under burst traffic, and strengthens test reliability across EVM version changes. These efforts collectively enhanced throughput, reduced operational risk, and accelerated feedback cycles for production workloads.
April 2025
6 Commits • 2 Features
Apr 1, 2025April 2025 — hiero-ledger/hiero-mirror-node: Delivered targeted test coverage for token fee management, implemented a critical performance optimization for token lookups, and hardened the REST/API and test suite against edge cases to improve reliability and operator confidence on Hedera network deployments. The work strengthens business value by accelerating token operations, reducing latency on large datasets, and reducing error-prone scenarios in production and test environments.
6 Commits • 2 Features
Apr 1, 2025April 2025 — hiero-ledger/hiero-mirror-node: Delivered targeted test coverage for token fee management, implemented a critical performance optimization for token lookups, and hardened the REST/API and test suite against edge cases to improve reliability and operator confidence on Hedera network deployments. The work strengthens business value by accelerating token operations, reducing latency on large datasets, and reducing error-prone scenarios in production and test environments.
April 2025
March 2025
6 Commits • 1 Features
Mar 1, 2025Monthly summary for 2025-03: hiero-ledger/hiero-mirror-node delivered Modularized Transaction Execution Service rollout with traffic routing. This involved gradual rollout with configurable traffic percentage, header-based traffic control, and cross-component status synchronization. Telemetry added: metrics and logging for transaction traffic splits. Privacy improvement: avoid printing full account data when payer is invalid. Tests expanded for modularized features in token fee scenarios. This release was supported by six commits: 56ed054c661ae032f7370332a7f51eb70e9b9fa6, 8f9aa6b05a0c866236bd467c72220ecbd933c926, 2abed4fad477b58b115c5a2d1909af47e3028764, 1449467fe8566d055f6a2911de8ba9d13437ca16, a0347bfabd1bb43e56aa6f7b6a5f715f314e3fcd, 2681291b3b3e7592bdd279fa553dca691c21dd31
March 2025
6 Commits • 1 Features
Mar 1, 2025Monthly summary for 2025-03: hiero-ledger/hiero-mirror-node delivered Modularized Transaction Execution Service rollout with traffic routing. This involved gradual rollout with configurable traffic percentage, header-based traffic control, and cross-component status synchronization. Telemetry added: metrics and logging for transaction traffic splits. Privacy improvement: avoid printing full account data when payer is invalid. Tests expanded for modularized features in token fee scenarios. This release was supported by six commits: 56ed054c661ae032f7370332a7f51eb70e9b9fa6, 8f9aa6b05a0c866236bd467c72220ecbd933c926, 2abed4fad477b58b115c5a2d1909af47e3028764, 1449467fe8566d055f6a2911de8ba9d13437ca16, a0347bfabd1bb43e56aa6f7b6a5f715f314e3fcd, 2681291b3b3e7592bdd279fa553dca691c21dd31
February 2025
4 Commits • 2 Features
Feb 1, 2025February 2025: For hiero-mirror-node, delivered two core items focused on reliability and compatibility. (1) Contract Call Tests Robustness and Account Handling Improvements—expanded testing coverage for contract call operations (burn, wipe, pause, freeze) across token types; ensured payer accounts and hollow account scenarios are correctly tested; fixed test failures in key test classes. Commits: e67266df2d666ebe856995467da8737514627679, 7b3c84ca0dd66f3ab8d879d5566415dd32c6401a, c7e376d0b5d8d6ecd6ea4603f2358339e93e3d2e. (2) Hedera App Library Version Upgrade and Compatibility—upgraded Hedera app library from 0.58.4 to 0.59.0 and adjusted related components to resolve compilation issues and ensure smooth integration. Commit: 8b4c7c0dc1f293bdc35eb54e5650abbeab68e00c.
4 Commits • 2 Features
Feb 1, 2025February 2025: For hiero-mirror-node, delivered two core items focused on reliability and compatibility. (1) Contract Call Tests Robustness and Account Handling Improvements—expanded testing coverage for contract call operations (burn, wipe, pause, freeze) across token types; ensured payer accounts and hollow account scenarios are correctly tested; fixed test failures in key test classes. Commits: e67266df2d666ebe856995467da8737514627679, 7b3c84ca0dd66f3ab8d879d5566415dd32c6401a, c7e376d0b5d8d6ecd6ea4603f2358339e93e3d2e. (2) Hedera App Library Version Upgrade and Compatibility—upgraded Hedera app library from 0.58.4 to 0.59.0 and adjusted related components to resolve compilation issues and ensure smooth integration. Commit: 8b4c7c0dc1f293bdc35eb54e5650abbeab68e00c.
February 2025
January 2025
8 Commits • 1 Features
Jan 1, 2025January 2025 monthly summary for hiero-ledger/hiero-mirror-node. Key developments include cryptographic key generation validation, code quality improvements, and test stabilization for precompile-related tests. These deliver business value by reducing key-generation errors, stabilizing CI, and improving deployment confidence.
January 2025
8 Commits • 1 Features
Jan 1, 2025January 2025 monthly summary for hiero-ledger/hiero-mirror-node. Key developments include cryptographic key generation validation, code quality improvements, and test stabilization for precompile-related tests. These deliver business value by reducing key-generation errors, stabilizing CI, and improving deployment confidence.
December 2024
8 Commits • 2 Features
Dec 1, 2024December 2024: Implemented a configuration-driven Admin Key exposure control for the Network Nodes API via a feature flag, enabling secure exposure toggling without API changes. Completed comprehensive code quality, CI/build stabilization across hiero-mirror-node, including Spotless formatting enforcement, SonarQube housekeeping, test cleanup, and build config tweaks. These efforts reduce release risk, improve maintainability, and accelerate future iterations. Technologies demonstrated include feature flags, configuration-driven API behavior, Spotless, SonarQube, CI/CD pipelines, and code refactoring.
8 Commits • 2 Features
Dec 1, 2024December 2024: Implemented a configuration-driven Admin Key exposure control for the Network Nodes API via a feature flag, enabling secure exposure toggling without API changes. Completed comprehensive code quality, CI/build stabilization across hiero-mirror-node, including Spotless formatting enforcement, SonarQube housekeeping, test cleanup, and build config tweaks. These efforts reduce release risk, improve maintainability, and accelerate future iterations. Technologies demonstrated include feature flags, configuration-driven API behavior, Spotless, SonarQube, CI/CD pipelines, and code refactoring.
December 2024
November 2024
2 Commits • 1 Features
Nov 1, 2024November 2024 highlights: Delivered a backend enhancement to hiero-mirror-node for network node visibility by exposing admin_key in the /network/nodes endpoint and adding a Node model with updates to NetworkNodeViewModel. This improves operational oversight and auditability of network nodes. Also completed a project-wide code formatting cleanup to boost readability and maintainability without altering behavior. These changes enhance API accuracy for network management and reduce future maintenance costs.
November 2024
2 Commits • 1 Features
Nov 1, 2024November 2024 highlights: Delivered a backend enhancement to hiero-mirror-node for network node visibility by exposing admin_key in the /network/nodes endpoint and adding a Node model with updates to NetworkNodeViewModel. This improves operational oversight and auditability of network nodes. Also completed a project-wide code formatting cleanup to boost readability and maintainability without altering behavior. These changes enhance API accuracy for network management and reduce future maintenance costs.
Activity
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Quality Metrics
Correctness87.8%
Maintainability84.4%
Architecture80.2%
Performance74.8%
AI Usage20.4%
Skills & Technologies
Programming Languages
GherkinGradleJavaJavaScriptKotlinMarkdownSQLShellSolidityYAML
Technical Skills
API DevelopmentAPI IntegrationAPI TestingBackend DevelopmentBug FixingBuild AutomationBuild ConfigurationCI/CDCachingCaffeine CacheCode AnalysisCode FormattingCode QualityCode Quality ToolsCode Refactoring
Repositories Contributed To
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