Jussi Koljonen
Software Architect at OpenPeppol
Espoo, Finland
Summary
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SeniorJussi Koljonen is a software architect based in Espoo, Finland with 12 years of experience designing and maintaining high-throughput e‑invoicing and document processing platforms. He architects systems that process hundreds of millions of transactions annually, specializing in interoperability across global e‑invoice standards such as EN16931, Peppol, EHF, XRechnung and many UBL/UN/CEFACT variants. Deep technical expertise in XML ecosystems (XSD, XSLT, Schematron), PKI/security (XMLDSIG, XMLENC, RSA), and production Ruby/JRuby development underpins his work to keep services reliable, compliant and performant at scale. An active contributor to standards governance, he serves on OpenPeppol’s Post Award Community change board, helping shape post‑award interoperability and compliance. Colleagues rely on him for future‑proofing architectures and pragmatic conversion/validation pipelines that evolve with regulation and transaction volume. His background ranges from embedded/mobile test automation to large enterprise integrations, giving him an uncommon blend of low‑level tooling experience and large system design.
12 years of coding experience
15 years of employment as a software developer
Finnish, English
Github Skills (45)
xslt10
xml10
json-parser9
json9
libxml29
validation-rules9
html-parser9
xml-schema9
xsd9
schematron9
sax9
edifact9
ubl9
libxslt9
nokogiri9
Programming languages (5)
Github contributions (5)
juskoljo/toki
Oct 2013 - Oct 2013
Contributions:34 commits, 1 issue in 2 days
juskoljo/vefa-ehf-postaward
Jan 2018 - Feb 2018
Contributions:2 pushes in 9 days
awardvalidation-rulesrulesvalidation
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