10/09/2026 updated
100 % available
Full Stack Engineer | TypeScript, React, Node.js, AI Agent Systems
Helsinki, Finland
Only remote
Bachelor in Business Information TechnologyAbout me
I’m a Full Stack Developer based in Helsinki with hands‑on experience building and operating production systems end‑to‑end. I work across backend, frontend, and infrastructure using Next.js, TypeScript, React, and C#/.NET, with a strong focus on reliability, performance, and maintainability.
DevOpsNode.jsNext.jsTypeScriptMulti-Agent SystemsBackendFull Stack DevelopmentReact NativeFront End Software Development
Frontend Development
Expertise in React 19, TypeScript, Next.js App Router, TanStack Start/Router, React Native, Tailwind, shadcn/ui, and operational dashboard UI for building modern, performant web applications.
Backend & API Development
Strong foundation in Node.js, Python, REST and API-centric architecture, third-party API integration, asynchronous programming, server functions and SSR, as well as C# and .NET fundamentals.
AI & Agent Systems
Hands-on experience with multi-agent orchestration and routing, agent tooling, RAG retrieval, structured output validation using Zod, evaluation and critique loops, tiered model routing for cost, and multi-provider integration including Mistral, Llama, Groq, and OpenAI.
Data & Databases
Proficiency in PostgreSQL, SQL, relational data modelling, pgvector, multi-tenant data separation, document ingestion, and ETL pipelines.
Infrastructure & DevOps
Practical experience with Docker, CI/CD using GitHub Actions, Vercel, Azure basics, Linux command line, and Git/GitHub and GitLab-style workflows.
Reliability & Observability
Knowledge of timeout, retry and provider fallback strategies, failure-mode design, integration hardening, and production incident diagnosis under time pressure.
Quality & Security
Application of Vitest unit and route testing, CodeQL static analysis, CI gating on typecheck, lint, test and build, prompt-injection hardening, and database-level access control.
Ownership & Product
Sole technical ownership of live systems, direct client and stakeholder interaction, turning ambiguous goals into specifications, and technical documentation.
Expertise in React 19, TypeScript, Next.js App Router, TanStack Start/Router, React Native, Tailwind, shadcn/ui, and operational dashboard UI for building modern, performant web applications.
Backend & API Development
Strong foundation in Node.js, Python, REST and API-centric architecture, third-party API integration, asynchronous programming, server functions and SSR, as well as C# and .NET fundamentals.
AI & Agent Systems
Hands-on experience with multi-agent orchestration and routing, agent tooling, RAG retrieval, structured output validation using Zod, evaluation and critique loops, tiered model routing for cost, and multi-provider integration including Mistral, Llama, Groq, and OpenAI.
Data & Databases
Proficiency in PostgreSQL, SQL, relational data modelling, pgvector, multi-tenant data separation, document ingestion, and ETL pipelines.
Infrastructure & DevOps
Practical experience with Docker, CI/CD using GitHub Actions, Vercel, Azure basics, Linux command line, and Git/GitHub and GitLab-style workflows.
Reliability & Observability
Knowledge of timeout, retry and provider fallback strategies, failure-mode design, integration hardening, and production incident diagnosis under time pressure.
Quality & Security
Application of Vitest unit and route testing, CodeQL static analysis, CI gating on typecheck, lint, test and build, prompt-injection hardening, and database-level access control.
Ownership & Product
Sole technical ownership of live systems, direct client and stakeholder interaction, turning ambiguous goals into specifications, and technical documentation.
Experience
Professional experience5 - 10 years
Freelancer since2026
Languages
GermanBasic knowledgeFinnishBasic knowledgeEnglishFluent
Project history
Architected a 7-agent orchestration pipeline using TypeScript, multi-agent orchestration, RAG, Zod specs, Mistral, Llama, and pgvector. Enforced typed Zod schemas at every stage boundary, routed work across tiered models for cost control, built a two-part verification layer, and hardened against adversarial input with prompt-injection protection.
Designed a reusable multi-tenant agent framework with strict per-tenant data separation using Next.js, PostgreSQL, Groq, GitHub Actions, Vitest, and CodeQL. Built a full CI/CD pipeline with parallel jobs, integrated CodeQL static security analysis, wrote Vitest suites, and automated deployment to Vercel.
Built and deployed a bilingual (FI/EN) customer-facing website using Next.js 14, React, TypeScript, SCSS, and i18next. Migrated the codebase from Create React App to the Next.js App Router with full bilingual support via react-i18next across seven pages. Configured HTTP security headers and deployed on Vercel with a custom domain.