opentripplanner/OpenTripPlanner
Feb 2025 – Jan 2026
7 Months active
Languages Used
Java
Technical Skills
Backend DevelopmentCode OptimizationFare CalculationJavaJava DevelopmentRefactoring
danielhep
PROFILE
Danielhep
Daniel Heppner contributed to the OpenTripPlanner repository by engineering robust fare calculation systems for complex transit scenarios. Over seven months, he delivered features such as CT Flex fare expansion, Kitsap Fast Ferry fare simplification, and Monorail pricing updates, consistently aligning code with evolving policy requirements. Daniel applied Java and backend development expertise to refactor legacy logic, centralize fare rules, and enhance test coverage, ensuring pricing accuracy and maintainability. His work included API integration, code formatting, and unit testing, addressing both new features and critical bug fixes. These efforts reduced technical debt, improved reliability, and streamlined future fare policy changes.
Overall Statistics
Feature vs Bugs
69%Features
Repository Contributions
25Total
Bugs
4
Commits
25
Features
9
Lines of code
974
Activity Months7
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51 peopleShared Repositories
51
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Work History
January 2026
3 Commits • 1 Features
Jan 1, 2026Month: 2026-01 — Focused on delivering a streamlined fare experience and improving code quality in the OpenTripPlanner repository. Key features delivered include the Kitsap Fast Ferry Fare Calculation Simplification, which consolidates fare types into a single calculation path for eastbound and westbound trips and updates the fare calculation to align with the latest requirements. The work included updating tests to reflect the new kitsap fare calculations. Major bug fix: OrcaFareService Code Cleanup, removing unused variables to improve code cleanliness and maintainability. These changes reduce pricing risk, simplify future rule changes, and improve test coverage. Overall impact: improved pricing accuracy and operational reliability, reduced technical debt, and strengthened maintainability. Technologies/Skills Demonstrated: Java-based backend refactoring, fare logic design, unit testing, and version control discipline with targeted commits.
3 Commits • 1 Features
Jan 1, 2026Month: 2026-01 — Focused on delivering a streamlined fare experience and improving code quality in the OpenTripPlanner repository. Key features delivered include the Kitsap Fast Ferry Fare Calculation Simplification, which consolidates fare types into a single calculation path for eastbound and westbound trips and updates the fare calculation to align with the latest requirements. The work included updating tests to reflect the new kitsap fare calculations. Major bug fix: OrcaFareService Code Cleanup, removing unused variables to improve code cleanliness and maintainability. These changes reduce pricing risk, simplify future rule changes, and improve test coverage. Overall impact: improved pricing accuracy and operational reliability, reduced technical debt, and strengthened maintainability. Technologies/Skills Demonstrated: Java-based backend refactoring, fare logic design, unit testing, and version control discipline with targeted commits.
January 2026
December 2025
2 Commits • 1 Features
Dec 1, 2025December 2025 — Key feature delivered: OrcaFareService fare pricing updates and readability improvements, including a formatting refactor for readability and updates to senior/electronic regular fare pricing to reflect new rates. Major bugs fixed: formatting issues in the fare service and related test failures stabilized (final test fix). Overall impact: improved pricing accuracy, reliability, and maintainability, enabling faster rollout of rate changes. Technologies/skills demonstrated: refactoring for readability, test stabilization, fare pricing domain knowledge, and disciplined version control.
December 2025
2 Commits • 1 Features
Dec 1, 2025December 2025 — Key feature delivered: OrcaFareService fare pricing updates and readability improvements, including a formatting refactor for readability and updates to senior/electronic regular fare pricing to reflect new rates. Major bugs fixed: formatting issues in the fare service and related test failures stabilized (final test fix). Overall impact: improved pricing accuracy, reliability, and maintainability, enabling faster rollout of rate changes. Technologies/skills demonstrated: refactoring for readability, test stabilization, fare pricing domain knowledge, and disciplined version control.
November 2025
2 Commits • 1 Features
Nov 1, 2025November 2025 monthly summary for opentripplanner/OpenTripPlanner: Delivered two high-impact changes that strengthen policy enforcement and technical reliability. Implemented Monorail Fare Policy Update: Free Rides for Youth by removing monorail fare calculations, simplifying the fare structure and ensuring youth eligibility is correctly enforced. This was backed by commit 26ab96a42e68df579bbf9c5059a528a455369b1d. Also refactored the fare calculation framework by moving non-specified fares into the fare model and fixing a cash-transfer calculation bug, reducing maintenance burden and improving correctness for agencies without GTFS-provided fares. Commit 087dd1fc5490860aaaad51f8b3e396c90a209dfa. Overall impact: clearer pricing for riders, more reliable fare computations, and a more maintainable codebase. Technologies: Java backend, fare model architecture, GTFS integration, Git-based version control, collaboration with policy/product teams.
2 Commits • 1 Features
Nov 1, 2025November 2025 monthly summary for opentripplanner/OpenTripPlanner: Delivered two high-impact changes that strengthen policy enforcement and technical reliability. Implemented Monorail Fare Policy Update: Free Rides for Youth by removing monorail fare calculations, simplifying the fare structure and ensuring youth eligibility is correctly enforced. This was backed by commit 26ab96a42e68df579bbf9c5059a528a455369b1d. Also refactored the fare calculation framework by moving non-specified fares into the fare model and fixing a cash-transfer calculation bug, reducing maintenance burden and improving correctness for agencies without GTFS-provided fares. Commit 087dd1fc5490860aaaad51f8b3e396c90a209dfa. Overall impact: clearer pricing for riders, more reliable fare computations, and a more maintainable codebase. Technologies: Java backend, fare model architecture, GTFS integration, Git-based version control, collaboration with policy/product teams.
November 2025
October 2025
3 Commits • 1 Features
Oct 1, 2025Monthly summary for 2025-10 focusing on delivering Monorail fare pricing enhancements and improving test coverage for Monorail fare calculations. Key outcomes include accurate pricing logic, UUID-based fare products, improved transfer/youth fare handling for Monorail, and robust test coverage to prevent regressions. The work enhances multi-agency pricing readiness and end-user pricing reliability, with measurable business value and maintainability gains.
October 2025
3 Commits • 1 Features
Oct 1, 2025Monthly summary for 2025-10 focusing on delivering Monorail fare pricing enhancements and improving test coverage for Monorail fare calculations. Key outcomes include accurate pricing logic, UUID-based fare products, improved transfer/youth fare handling for Monorail, and robust test coverage to prevent regressions. The work enhances multi-agency pricing readiness and end-user pricing reliability, with measurable business value and maintainability gains.
September 2025
6 Commits • 2 Features
Sep 1, 20252025-09 Monthly summary for OpenTripPlanner (opentripplanner/OpenTripPlanner). Focused on delivering durable fare infrastructure, stabilizing the fare model, and strengthening maintainability to support policy changes and cross-agency pricing. Key features delivered: - Water Taxi Fare: Permanent Fare Structure implemented; removed Sept 1 conditional to ensure correct and consistent fares for Vashon and West Seattle. Commit: 3a94be0dd8a10725aecf16b80f9424fccc70fe57. - OrcaFareService Overhaul: Leg-Specific Fares and Transfer Logic. Refactored to generate leg-specific fare offers, improved inter-agency and same-agency transfer handling, removed dead code, streamlined filtering of valid fare products and transfer calculations; updated tests accordingly. Commits include: rewrite Orca fare model to generate fare products; format code; clean up some logic; remove unused function; fix test error. Major bugs fixed: - Stabilized fare-related test failures after OrcaFareService refactor; removed dead code paths that caused flaky behavior; ensured transfer logic aligns with updated fare products across agencies. Overall impact and accomplishments: - Improved pricing accuracy and consistency across agencies, reducing revenue leakage and enhancing user trust. - Enhanced maintainability and test coverage, enabling faster iterations on fare policies. - Clear separation of concerns between fare generation, transfer handling, and validation logic, setting a solid baseline for future policy changes. Technologies/skills demonstrated: - Large-scale refactoring and domain modeling (leg-specific fares, transfer logic). - Test-driven development and test suite stabilization (test updates and error fixes). - Code quality improvements: formatting, dead code removal, and function cleanup. - Cross-service collaboration readiness across multi-agency fare systems.
6 Commits • 2 Features
Sep 1, 20252025-09 Monthly summary for OpenTripPlanner (opentripplanner/OpenTripPlanner). Focused on delivering durable fare infrastructure, stabilizing the fare model, and strengthening maintainability to support policy changes and cross-agency pricing. Key features delivered: - Water Taxi Fare: Permanent Fare Structure implemented; removed Sept 1 conditional to ensure correct and consistent fares for Vashon and West Seattle. Commit: 3a94be0dd8a10725aecf16b80f9424fccc70fe57. - OrcaFareService Overhaul: Leg-Specific Fares and Transfer Logic. Refactored to generate leg-specific fare offers, improved inter-agency and same-agency transfer handling, removed dead code, streamlined filtering of valid fare products and transfer calculations; updated tests accordingly. Commits include: rewrite Orca fare model to generate fare products; format code; clean up some logic; remove unused function; fix test error. Major bugs fixed: - Stabilized fare-related test failures after OrcaFareService refactor; removed dead code paths that caused flaky behavior; ensured transfer logic aligns with updated fare products across agencies. Overall impact and accomplishments: - Improved pricing accuracy and consistency across agencies, reducing revenue leakage and enhancing user trust. - Enhanced maintainability and test coverage, enabling faster iterations on fare policies. - Clear separation of concerns between fare generation, transfer handling, and validation logic, setting a solid baseline for future policy changes. Technologies/skills demonstrated: - Large-scale refactoring and domain modeling (leg-specific fares, transfer logic). - Test-driven development and test suite stabilization (test updates and error fixes). - Code quality improvements: formatting, dead code removal, and function cleanup. - Cross-service collaboration readiness across multi-agency fare systems.
September 2025
August 2025
5 Commits • 1 Features
Aug 1, 2025In August 2025, delivered key enhancements and fixes for OpenTripPlanner. Implemented Fare Calculation Updates for Sep-Oct 2025 across Kitsap Fast Ferry and Water Taxi, removing outdated date logic and aligning tests with intended scenarios. Performed Code Formatting Cleanup for OrcaFareService to improve readability with no functional changes. Fixed test issues and stabilized the fare calculation workflow, reducing risk of regressions in the upcoming period. These efforts improved fare accuracy, test reliability, and code maintainability, enabling smoother rollout of fare changes and faster onboarding for future changes.
August 2025
5 Commits • 1 Features
Aug 1, 2025In August 2025, delivered key enhancements and fixes for OpenTripPlanner. Implemented Fare Calculation Updates for Sep-Oct 2025 across Kitsap Fast Ferry and Water Taxi, removing outdated date logic and aligning tests with intended scenarios. Performed Code Formatting Cleanup for OrcaFareService to improve readability with no functional changes. Fixed test issues and stabilized the fare calculation workflow, reducing risk of regressions in the upcoming period. These efforts improved fare accuracy, test reliability, and code maintainability, enabling smoother rollout of fare changes and faster onboarding for future changes.
February 2025
4 Commits • 2 Features
Feb 1, 2025February 2025 monthly summary for opentripplanner/OpenTripPlanner: Implemented CT Flex Fare Expansion and CT Fare Logic Refactor with date handling enhancements. These changes deliver business value by enabling accurate CT Flex fare application across routes, agencies, and effective dates, and by aligning fare checks with the March 1, 2025 boundary. Centralized CT local reduced fare logic into reusable methods and standardized date handling with LocalDate, reducing maintenance risk and future-proofing the codebase for upcoming fare changes.
4 Commits • 2 Features
Feb 1, 2025February 2025 monthly summary for opentripplanner/OpenTripPlanner: Implemented CT Flex Fare Expansion and CT Fare Logic Refactor with date handling enhancements. These changes deliver business value by enabling accurate CT Flex fare application across routes, agencies, and effective dates, and by aligning fare checks with the March 1, 2025 boundary. Centralized CT local reduced fare logic into reusable methods and standardized date handling with LocalDate, reducing maintenance risk and future-proofing the codebase for upcoming fare changes.
February 2025
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Quality Metrics
Correctness91.2%
Maintainability89.6%
Architecture86.0%
Performance84.0%
AI Usage20.8%
Skills & Technologies
Programming Languages
Java
Technical Skills
API IntegrationAPI developmentBackend DevelopmentCode FormattingCode OptimizationCode RefactoringFare CalculationFare Calculation LogicFare System ImplementationJavaJava DevelopmentRefactoringTestingTransit SystemsUnit Testing
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