Joel Lappalainen
Systems Specialist at AktiaDuetto Ab
Helsinki, Finland
Summary
🤩
Rockstar🎓
Top SchoolJoel Lappalainen is a Systems Specialist based in Helsinki with nine years of hands-on experience building and operating Linux-driven infrastructure, integrations, and identity management solutions. He blends strong backend development skills—evidenced by contributions to the OpenTripPlanner project enhancing graph building and GraphQL APIs—with practical expertise in configuration management (Ansible), container and server administration, and service management. Joel has supported and designed IAM/EIM solutions, delivered 2nd-level support and documentation architecture, and consulted on SSO and federation technologies like SAML2, ADFS, and OAuth. His background spans enterprise integration work with Java, XSLT and IIB as well as automation tooling and observability in production. Comfortable both coding and running services, he emphasizes clear documentation and pragmatic designs that improve operability. Despite broad competence, he stays curious and values continual learning—an attribute reflected in steady progression from hands-on IT roles to specialist systems work.
9 years of coding experience
2 years of employment as a software developer
Further Qualification in Maintenance, Further Qualification in Maintenance at Kunnossapitotehdas OyInformation Technology, Information Technology at Ajou UniversityBachelor of Business Administration (B.B.A.) in IT, Information Technology, Bachelor of Business Administration (B.B.A.) in IT, Information Technology at Haaga-Helia University of Applied Sciences
Japanese, Finnish, Swedish, English
Github Skills (11)
opentripplanner10
javas10
api10
apidoc10
java10
wpgraphql9
wordpress-graphql9
graphql9
data-structures8
data-structure8
software-design8
Programming languages (10)
Github contributions (5)
opentripplanner/OpenTripPlanner
Sep 2018 - Jan 2023
An open source multi-modal trip planner
Role in this project:
Back-end Developer
Back-end DeveloperContributions:1404 reviews, 438 commits, 258 PRs in 4 years 4 months
Contributions summary:Joel primarily contributed to the backend codebase by implementing new parameters for the graph builder, including functionality for handling elevation units, and supporting transit-related features. These changes involved modifications to Java classes, particularly concerning graph building parameters, data structures, and modules. The user also made several updates to the GraphQL API, including the addition of route type and entity-related queries, which enhances the API's capabilities.
multi-sourcemulti-modaltrip-plannermodalplanner
HSLdevcom/hsl-timetable-container
Jan 2019 - Jan 2025
Contributions:13 PRs, 13 pushes, 13 branches in 6 years 1 month
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