Software Engineer - TypeScript, Node.js & AWS

Salt is currently hiring a Software Engineer for a client of ours in Amsterdam. Role is freelance(kvk/zzp needed) for 12 months, paying around 95-100 euros an hour. We’re looking for a Software Engineer to design, build, deploy, and operate reliable, scalable software services. You’ll take end-to-end ownership of solutions, contribute to architecture and technical decisions, and work closely with product and engineering teams. Key Responsibilities Design and build scalable, secure, and maintainable applications and APIs.Own solutions end-to-end — from design and development through testing, deployment, monitoring, and production support.Build reliable distributed systems using TypeScript/Node.js, AWS Lambda, S3, DynamoDB, queues, workers, and orchestration.Design for resilience with timeouts, retries, idempotency, circuit breakers, dead-letter handling, and graceful degradation.Apply strong testing practices, including unit, integration, and contract testing.Monitor and improve production systems using logs, metrics, traces, SLIs, SLOs, and meaningful alerts.Investigate production issues, lead root-cause analysis, and implement long-term reliability improvements.Contribute to architecture, technical design, and continuous improvement initiatives.Collaborate effectively with product, engineering, and partner teams to clarify requirements and solve complex problems.Must-Have Skills Strong experience with TypeScript/Node.js and API development.Hands-on experience with AWS and serverless/distributed systems.Strong understanding of queues, workers, orchestration, scaling, retries, and idempotency.Experience with S3, DynamoDB, security, observability, testing, CI/CD, and production operations.Ability to independently deliver software from design through production.Strong programming fundamentals and experience writing clean, reusable, maintainable code.Experience with coding agents and modern AI-assisted development.Strong problem-solving, communication, and collaboration skills.