Teemu – React, Typescript, Node.js

A next-generation construction automation management platform.

• Architected and developed a full-stack building automation SaaS using React Router v7 with SSR;
• Implemented Infrastructure as Code with Pulumi/TypeScript for managing Google Cloud Platform deployments and secure network architecture with VPC connectors and VPN software;
• Integrated AI for automated data analysis;
• Established a comprehensive validation system utilizing Zod across the entire stack (environment, forms, API, database) with 140+ test cases using Vitest and React Testing Library.

A platform for event visitors to preorder goods and services in events.

• Built an event pre-ordering platform on Shopify from the ground up, scaling to hundreds of repeat customers;
• Designed and implemented a custom storefront using Liquid templates, Tailwind CSS, and JavaScript;
• Optimized theme performance and accessibility to meet WCAG standards;
• Developed proof-of-concept account and checkout extensions using Remix;
• Created collections and products management application with Remix and Shopify Admin API for streamlined catalog operations;
• Built a vendor management application for order processing, enabling partners to handle fulfillment through a dedicated interface;
• Integrated with Shopify's GraphQL API and implemented webhook processing using Node.js;
• Automated cloud deployments via GitHub Actions and Google Cloud Run;
• Collaborated with partner vendors on API integration specifications;
• Contributed to technical recruitment by assessing candidate assignments and conducting interviews.

Finland's national register for social welfare, healthcare, and early childhood education service providers. Operated by Valvira, the central supervisory authority under the Ministry of Social Affairs and Health, the platform consolidates organization data, service information, and licensing into a unified electronic system used by thousands of service providers nationwide.

• Developed full-stack features for Finland's national service provider registration system using Clojure, ClojureScript, and Re-frame, applying functional programming paradigms throughout
• Contributed to the application's design system by creating new UI components and evaluating compatibility of components from existing government systems

City of Helsinki's online service where parents apply for early childhood education placements and enrol children in school. The Education Division's e-service handles thousands of applications annually for Helsinki's public daycare and school system.

• Developed full-stack features using React within a microservice architecture spanning multiple development teams;
• Built a multi-step dynamic application form for child daycare placement where available options adapt based on previous answers, streamlining the application process for parents;
• Integrated and extended the City of Helsinki's design system components to ensure consistency with other municipal digital services;
• Collaborated across teams in a distributed microservice environment to deliver cohesive user-facing functionality.

Finland's national start-up grant system supports new entrepreneurs during their first year of business. Administered by the Employment and Economic Development Offices (TE Offices), the service processes thousands of grant applications annually, evaluating eligibility based on business viability, entrepreneur skills, and market conditions.

• Conducted frontend-heavy full-stack development using React, C# .NET, MSSQL, and Azure;
• Modernized a complex, legacy start-up grant application form with numerous interdependent fields and conditional logic;
• Simplified the user experience for applicants navigating eligibility requirements across multiple criteria.

The official online service of Finland's Social Insurance Institution, providing information on social security benefits to millions of Finnish citizens, employers, and partner organisations. The platform serves as the primary digital gateway for understanding and accessing benefits including healthcare, unemployment, housing, and family support.

• Upgraded legacy codebase to meet current industry standards, improving maintainability and performance
• Migrated Java APIs to Node.js applications, modernizing the backend architecture

A playlist reporting application with integrations to a radio studio's playout software, exporting playlist reports in the format required by music copyright organisations.

• Designed and built playlist reporting software from the ground up, gathering requirements directly from radio hosts and DJs;
• Integrated with studio playout software API to automatically capture track metadata during broadcasts;
• Collaborated with copyright organisations (Teosto, Gramex) to implement compliant reporting formats;
• Automated deployments to Heroku for continuous delivery;
• Eliminated manual data entry of approximately 87,600 songs per year, freeing staff to focus on content creation.