Full Stack Engineer

About the Company Helion Research is a market research agency specialised in Mystery Shopping & Customer Experience Research, active in over 90 countries for multinational retailers, manufacturers and service providers. We are bringing more of our technology development in-house — and looking for a full-stack developer to help build it. About the Role You will join a small internal development team and work closely with our technical lead, management and business users. Because the team is small, you get real responsibility early: your own components, direct contact with the people who use what you build, and a say in technical decisions. You won't be expected to figure everything out alone. Responsibilities Build features across our TypeScript stack: React frontends (Vite, TailwindCSS, TanStack Query) and typed backends (Hono, tRPC, Drizzle on PostgreSQL)Connect those applications to Helion systems, databases and external APIsBuild AI features into the product, such as LLM-supported grading and validation of research dataHelp make AI-generated output reliable enough for production useTake prototypes to production: testing (Vitest, Playwright), documentation, code qualityTry different technical approaches and measure what works Qualifications 1 – 4 yrs experience — ideally Required Skills Good software-development fundamentalsExperience with full-stack, backend or web application developmentSolid TypeScript — used across the entire stackReactDatabases and SQL (we run on PostgreSQL)Building or integrating APIsGit / GitHubAble to read existing code and build reliable new functionality on top of itGenuine interest in building with LLMs — work, side projects, studies or open sourceBasic understanding of LLM applications: inference cost/time, and how RAG fits togetherComfortable working primarily from our Antwerp office Preferred Skills Bun, Vite, TailwindCSS, Hono, tRPC, Drizzle, Zod, TanStack QueryCloudflare Workers or other serverless platformsTesting with Vitest, Playwright or similarDockerAuthentication, permissions & application securityPDF or image processing Pay range and compensation package Salary based on experience + extra-legal benefits Office in city centre of Antwerp 2 days work from home Full-time, permanent position, Antwerp, Belgium Equal Opportunity Statement We are committed to diversity and inclusivity in our hiring practices. Apply: send CV + motivation to jobs@helionresearch.com