By day, a software engineer at EUIPO. Through my consulting venture JNS Software House, I led the system that routes 200,000+ outbound social-security payments a month through Greece's DIAS network, plus the IDIKA → e-EFKA data migration. 10+ years of public-sector and enterprise track record.
About
I'm Ioannis. I've spent the last decade designing and delivering software where downtime is not optional — public-sector payment infrastructure, EU intellectual-property systems, social-security data migrations, commercial ERP integrations.
By day I'm a software engineer at EUIPO (via Altia–Unisys), working on large-scale enterprise Java systems.
Alongside that, through JNS Software House — a 4-person team I co-founded and lead technically — we delivered the system that routes 200,000+ outbound IDIKA payments a month through Greece's DIAS network (live since November 2025), and are delivering the IDIKA → e-EFKA migration. Before JNS I co-founded CodeDux and shipped ERP Connector, a commercial WooCommerce plugin sold under subscription to SME clients.
I take on a small number of consulting engagements per year. If your team needs a senior engineer who can own architecture, ship to production, and stick around for support — let's talk.
Selected engagements · 2017—present
Designed and delivered the system that routes IDIKA's monthly settlement cycles through the DIAS interbank network. Live in production since November 2025, running end-to-end every month. Currently also delivering the IDIKA → e-EFKA data migration pipeline.
Owned end-to-end: architecture, PHP backend, custom MySQL schema, ReactJS admin UI, deployment, and 365-day customer support. Cut typical ERP integration time from 1–2 months to 2–3 days. Sold under monthly and annual subscriptions across Greece.
erpconnector.grWorking across the EUIPO ecosystem — not only the Greek implementation, but the shared European platform and country systems such as Austria. Building and integrating new components, modernising legacy Java applications, resolving production issues across microservices, and aligning with EUIPO and OBI stakeholders. Stack spans Java EE, Spring Boot, Hibernate, Mule ESB, ElasticSearch, MongoDB, Oracle, WildFly, Tomcat.
Most engagements under NDA · happy to discuss specifics privately
Reference
“Ioannis did outstanding work when we delivered together at the Greek Ministry of Development.”
Services
A focused set of engagements where I can deliver disproportionate value. Each engagement is scoped, time-boxed, and outcomes-first.
Designing scalable backends, microservices, and integration layers in Spring Boot, Java EE, .NET Core, and PHP. Modernising legacy stacks without breaking what already ships.
Mission-critical systems for ministries and EU institutions. Built for compliance, observability, and long-term maintainability.
Full-stack delivery for SaaS, e-commerce, and ERP integration products. From architecture to customer support, end to end.
Fractional CTO and architecture review for teams that need senior judgment without a full-time hire.
Stack
Deep in Java/Spring and the .NET ecosystem, full-stack across modern JavaScript. Comfortable picking the right tool — not always the trendiest one.
Recognised · Active · 2024—present
Standards held, and the standards I help write.
Beyond client work, I author exam question banks and sit on examination committees that shape how software professionals are evaluated and certified in Greece.
Scientific Examination Committee · Question Bank Author
Scientific examination committee member for iCert’s certification programmes. Author original question banks and review existing exam content across multiple domains — including cybersecurity, programming fundamentals, and algorithms — ensuring question quality, accuracy, and alignment with each programme’s certification standards.
Certified Mentor
Formal mentoring credential issued by the University of West Attica. Recognised authority on guiding engineers, structuring code-review practice, and supporting career development for software professionals.
Engagement
Three formats, depending on what you need. All start with a free 30-minute conversation — pick whichever fits and we'll go from there.
3–12 months
You have a defined scope and need a senior engineer to own architecture and ship it.
Best for
2–6 weeks
You need a second pair of senior eyes on architecture, security, or scaling decisions before you commit.
Best for
Ongoing
Your team needs senior judgement and direction without the cost of a full-time CTO.
Best for
Need a full team for a larger build? I take those on through my studio, JNS Software House.
Each card opens a pre-filled email · or write directly to info@jcharitos.gr
Get in touch
The fastest way to start is a 30-minute call. Tell me a little about what you're working on and where you're stuck, and I'll come back within two business days with whether and how I can help.