Work on Windmill's **Rust backend** - the execution engine, workers, language runtimes, API layer, and infrastructure that powers thousands of production deployments.
* **Execution engine**: scheduling, job queues, worker orchestration, flow execution with branching, parallelism, retries, and error handling.
* **Language runtimes**: maintain and extend sandboxed runtimes for Python, TypeScript, Go, Bash, SQL, and more.
* **Performance & reliability**: profiling, optimization, resource management. Our users run mission-critical workloads - correctness and uptime matter.
* **Infrastructure**: PostgreSQL schema design, caching, networking, deployment tooling.
## **Who we're looking for**
**This is a senior role.** We're looking for someone who has operated distributed systems at scale and can teach us from day one - showing us PostgreSQL patterns, distributed systems techniques, and architectural improvements we haven't considered yet.
* Proven experience building and operating **distributed systems at scale** - not theoretical, you've done it in production
* Deep **PostgreSQL** expertise - query optimization, schema design, concurrency control, partitioning, replication. You know what breaks at scale and how to fix it.
* Strong systems programming skills - **Rust** experience strongly preferred, otherwise C/C++ with willingness to switch
* You bring opinions and techniques from previous infrastructure work that will make Windmill better immediately
* You enjoy hard infrastructure problems and care about correctness
### **Example projects in your first 3 months**
* Redesign the job queue to handle bursty workloads with thousands of concurrent jobs without degrading scheduling latency
* Implement a new worker orchestration strategy that improves resource utilization across heterogeneous deployments (2 to 600 workers)
* Optimize critical PostgreSQL queries and schema for customers with millions of completed jobs - partitioning, indexing, vacuum tuning
* Add a new language runtime (e.g., Java, C#) with proper sandboxing, dependency management, and execution feedback
* Build observability tooling - distributed tracing across the flow execution engine to diagnose slow or failing steps in production
## **Offer details**
**Location**: Paris hybrid (\~3 days/week) or remote within France
**Contract**: Full-time / CDI
**Salary**: €60K–€90K gross + top of market for level + 20% bonus on collective milestones
Visa sponsorship is offered for this role.
