Full Stack Engineer

Salt is currently hiring a skilled Fullstack Engineer with a strong focus on Backend technologies.

The role is a 6 month contract paying 100 euros an hour for a freelancer with KVK/ZZP.

Core Software Engineer – Platform Experience

We’re looking for a Core Software Engineer to help modernize and scale a global platform powering partner integrations. This is a hands-on role focused on transforming legacy systems into cloud-native, high-performing services.

What You’ll Do

• Lead modernization of core services, migrating legacy database layers to JOOQ
• Drive framework migration from Dropwizard to Spring Boot 3.x
• Replace direct database access with scalable API-based integrations
• Decommission legacy Perl and Java endpoints and streamline architecture
• Manage traffic migration, monitor performance, and safely retire old systems
• Ensure high reliability with strong test coverage, feature flags, and observability (SLIs/SLOs)

What We’re Looking For

• 3+ years of backend experience with Java (Spring Boot preferred)
• Strong knowledge of MySQL/PostgreSQL and data access patterns
• Experience modernizing legacy systems or migrating monoliths
• Familiarity with JOOQ or similar tools
• Bonus: experience working with or migrating Perl-based systems
• Solid system design skills (APIs, caching, batch processing)
• Strong communication and collaboration skills