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