Senior Software Developer - Kultakiertue Oy - Helsinki, Finland

<p>Are you looking for a responsible role in a fast-growing Helsinki-based scale-up with strong multinational business and proven growth? Do you have solid experience in software development — and do you take security as seriously?<br><br>How does a key role in a rapidly growing Finnish success story sound? At Kultakiertue, we are the market leader and pioneer in the purchasing and evaluation of precious metals. We already operate throughout the Nordics, Europe and the USA — and we keep expanding into new markets. More than 100 professionals work within our unique service concept, and our growth is only accelerating. Now is the perfect time to join the this journey.<br><br>We're looking for a <strong>hands-on Senior Developer</strong> to build and scale our internal software ecosystem together with our in-house engineering team — <strong>throughout the Nordics, Europe and North America</strong> — using modern frameworks and tools like SvelteKit, Vercel, Supabase and PostgreSQL.<br><br>Our platform runs the whole business end to end: online booking for customers, a field application for our purchasing agents, and admin tooling for payments, controlling and compliance. Because we handle customer data, banking and regulatory reporting to authorities in multiple countries, security and data protection are not an afterthought for us — they are a core feature of the product. You'll help keep it that way as we expand into new markets.<br><br>## Key responsibilities<br><br>- Develop new features and integrations across our booking, field-agent and admin applications<br>- Roll out our services in new countries, including country-specific compliance and reporting requirements<br>- Own security in day-to-day development: access control, secure handling of personal and financial data, and safe integration patterns<br>- Contribute to secure architecture and technology decisions — threat modeling, testing, code review, dependency and secrets hygiene<br>- Build and maintain integrations with payment providers, accounting systems and authority reporting interfaces<br>- Monitor and optimize workflows, data quality and system reliability<br>- Support broader IT and software needs across the company<br><br>## What you bring<br><br>- Proven track record building complex, mobile-first web apps (Svelte/SvelteKit or similar)<br>- Strong experience in backend and/or frontend development (Node.js, TypeScript, React, Vue or similar)<br>- Solid database and integration skills (PostgreSQL, REST APIs, row-level security a plus)<br>- A security-first mindset: you think about authentication, authorization, PII handling and the OWASP Top 10 as part of normal development — not as a separate phase<br>- Experience working with sensitive data (personal data, payments, or regulated/compliance-heavy domains) is a strong plus<br>- Familiarity with GDPR and practical data-protection engineering is appreciated<br>- Experience in fast-paced startup environments<br>- Fluent English (Finnish or other Nordic languages are a plus)<br><br>## What we offer<br><br>- A truly agile, tight team environment where your ideas matter<br>- Responsibility and freedom to influence architecture, technologies, security practices and ways of working<br>- Unlimited tokens and resources for modern tools and technologies<br>- Real ownership of security in a domain where it genuinely matters — precious metals, payments and regulatory reporting<br>- A supportive, skilled, and growing team<br>- Hybrid role requiring presence at our Käpylä office for few days a week<br>- Competitive salary and company bonus scheme<br>- Career growth opportunities in a rapidly scaling company<br><br>## More information<br><br>The salary for this position ranges from <strong>€6,000 to €7,500 per month</strong>, depending on the selected candidate's skills and experience.<br><br>## Interested?<br><br>Please submit your <strong>CV and application, including your salary expectations</strong>. We review applications on an ongoing basis, so we encourage you to apply as soon as possible.<br><br>Let's talk more soon! </p>