Software architect · full-stack developer · AI specialist
Jürgen Hannus
I build software that ships — and architecture that lasts.
15+ years across Java & Spring enterprise systems, Estonian e‑government, and international SaaS. Today I bring AI — LLMs, RAG, MCP and agentic workflows — into production, and ship my own products.
Selected work
Products I've built and shipped
Independent products — each live in production and built end-to-end: data pipeline, modelling, design and deploy.
Stack & expertise
What I work with
A pragmatic, full-stack toolkit — deep on the JVM and cloud, increasingly centred on getting AI to production.
AI / Machine learning
Languages
Backend
Cloud & infrastructure
Frontend
Data & messaging
CI / CD
Testing
Observability
Integration
Career
A track record across e‑gov, fintech and SaaS
From national e‑government platforms on X‑Road to international AI SaaS — as developer, lead and architect.
Trinidad Wiseman
2025 — presentArchitect / Lead Software Developer
Technical architect and lead full-stack developer on the modernized Estonian national export portal (EXPO) — unified digital services, export guidance and AI-powered translation of user-generated content. Improving CI/CD and internal tooling, mentoring backend developers, enforcing standards.
Java 25Spring Boot 4Angular 20Microservices / MFEX-RoadKubernetesRabbitMQOpenAILead Software Architect
Led architecture of an AI-powered legal practice-management SaaS with built-in CRM for law firms worldwide — security (OWASP remediation, SAST), AWS infrastructure and observability, AI-driven features, PostgreSQL performance, release management and team hiring & mentoring.
Java 21Spring Boot 3ReactTypeScriptAWS (ECS, RDS, S3)PostgreSQL RLSDatadogOpenAIFinestmedia
2023 — 2024Architect / Lead Software Developer
Architected Estonian state information-system services — the RIHA global management system, the consent service and a personal-data tracker — on X-Road. Led developers, drove code quality and clean-code practices, and presented on AI across the company.
Spring Boot 3Java 17Angular 15PostgreSQLX-RoadSOAPDockerCamelot Technologies
2022 — 2023Architect / Developer
Designed and delivered a Spring backend gateway between a Vue.js frontend and Java services, with user registration, authentication and authorization (JWT + 2FA).
Spring Boot 3Java 17PostgreSQLWebSocketPrometheusGrafanaLead Software Developer
Architected Futugrid — a fully automated real-time system managing household plug-in devices to improve grid efficiency and savings — and led the Health & Well-being information system (TeIS) for work-safety management.
Java 17Spring Boot 3KafkaAWS IoTKubernetesVue.jsCamundaGrafanaIcefire
2013 — 2019Software Developer
Built tax, customs and compliance systems for the Estonian Tax and Customs Board, PlanetID mobile authentication, and self-service applications for Elisa and Luminor Bank.
JavaSpring MVC / BootOraclePostgreSQLCamunda BPMNSOAP / RESTKnowit (flowit)
2011 — 2012Software Developer
CRM development for Tre (Sweden) and automated-testing tooling for SK ID Solutions (TempelPlus).
JavaPL/SQLSOAPTibcoSEB Bank
2010 — 2011Software Developer
Cost-budgeting and monitoring web application (EIS).
PL/SQLOracle APEXJavaScript
About
Software architect. Full-stack developer. Shipping AI.
I'm Jürgen Hannus — a software architect, senior full‑stack developer and AI specialist based in Tallinn, Estonia. Over 15+ years I've designed and built Java and Spring enterprise systems for national e‑government (on X‑Road), banks and international SaaS companies.
I work end-to-end: shaping architecture and CI/CD, leading and mentoring teams, hardening security (OWASP, SAST), tuning PostgreSQL, and pushing AI — LLMs, RAG, MCP and agentic workflows — from prototype into production. I also present regularly on AI and software engineering.
I also ship my own products — small, fast, data‑driven web apps, built and run entirely by me.
In brief
- Based in
- Tallinn, Estonia
- Education
- TTÜ IT College — IT Systems Development
- Languages
- Estonian (native) · English (professional) · German (working)
- Speaks on
- AI & software engineering
FAQ
Frequently asked questions
Quick answers about what I do, my stack, and working together.
What does Jürgen Hannus do?
Jürgen Hannus is a software architect, senior full‑stack developer and AI specialist based in Tallinn, Estonia. He has 15+ years of experience building Java and Spring systems for Estonian e‑government, banks and international SaaS — and now takes AI into production.
What is his technology stack?
Java and Spring Boot on the backend; TypeScript with Angular, React, Vue and Next.js on the front end; AWS, Docker and Kubernetes in the cloud; PostgreSQL, Kafka and RabbitMQ for data; and LLMs, RAG, MCP and the OpenAI API for AI.
Does he build AI integrations?
Yes. As an AI specialist he takes AI from prototype to production — LLM features, RAG pipelines, MCP servers and agentic workflows — and integrates them into existing Java and full‑stack systems. He also speaks regularly on AI and software engineering.
Is Jürgen Hannus available for hire?
He's open to software architecture, full‑stack development and AI‑integration work, for Estonian and international clients. The fastest way to reach him is email at jyrgen@hannus.ee.
Let's build something.
I'm open to software architecture, full‑stack development and AI‑integration work — and always happy to talk shop. The fastest way to reach me is email.
jyrgen@hannus.ee