Available for part-time & project work
Ship software that
moves fast and holds up.
I build backend systems that are fast, reliable, and easy to maintain — across telecom, finance, and EV, for teams of all sizes.
Whether you have a team already or just need a trusted pair of hands — I work part-time, full-time, or anywhere in between.
Based in Amsterdam, Netherlands
Jan Haitjema
Freelance Backend Engineer
Battle-Tested Across Industries
Shipped production systems across industries where software has to work.
Agencies
Fast-paced, multi-client environments where you learn to scope tight, deliver on time, and context-switch without dropping the ball. This is where I learned to move quickly without breaking things.
Telecom
High-throughput, high-availability systems that serve millions. Data pipelines, network integrations, and platforms where uptime is everything. Built to handle scale from day one.
Finance
Regulated, precise, and unforgiving. Reporting engines, data reconciliation, workflow automation, and API integrations where accuracy and auditability are non-negotiable. Familiar with ISO 27001, BIO, pentesting, and security compliance.
EV & Automotive
Software at the intersection of hardware and infrastructure. Charging networks, fleet management, real-time data, and the kind of systems that power the transition to electric mobility.
What I Build
The work I keep coming back to, project after project.
API Integrations
Connecting systems that weren't designed to talk to each other. REST, GraphQL, gRPC, webhooks, event-driven architectures — I've wired them all. Clean contracts, solid error handling, and documentation that actually helps.
Data Processing
Ingesting, transforming, and routing data at scale. ETL workflows, stream processing, batch jobs, and the kind of plumbing that makes everything else possible. Built for reliability, not just speed.
Reports & Workflows
Turning raw data into actionable insights. Automated reporting, business workflow engines, approval chains, and dashboards. The kind of tooling that makes teams faster and decisions clearer.
Built for the Long Run
Most of my backend work is written in Go. It produces fast, lightweight services that are easy to deploy and straightforward for your team to maintain long after the engagement ends.
Reliable systems that stay simple as they scale.
Ready to build something?
Whether you need an extra pair of hands or someone to lead the project end-to-end.
Get in Touch