Job Description
Azul provides the world’s most trusted Java platform, founded on open source and delivered by the world’s largest independent Java engineering team, and is the only company 100% focused on Java. Millions of Java developers, hundreds of millions of devices and the world’s most highly regarded businesses trust Azul to power their applications with exceptional capabilities, performance, security, value, and success.
As a Staff Software Engineer, you will be a technical leader who designs, implements, and optimizes core VM subsystems—runtime, JIT/AOT compilation, memory management, scheduling, and OS/hardware interfaces. You will set architecture direction, mentor engineers, and collaborate cross‑functionally to ship production‑grade features that move key performance and latency metrics.
Key Responsibilities
- Lead the design and architecture of core VM components (runtime services, JIT/AOT compiler pipelines, GC, thread scheduling, synchronization primitives).
- Own end‑to‑end delivery of complex features from ideation and design reviews to implementation and benchmarking.
- Profile and optimize latency‑critical paths across runtime, compiler, OS, and hardware boundaries (NUMA, caches, micro‑architecture, syscall/IO paths).
- Establish technical standards and code quality practices; drive design documents, RFCs, and engineering reviews.
- Collaborate with performance engineering to define and hit SLOs for tail latency, throughput, footprint, and startup/warm‑up.
- Advance observability in the VM (metrics, tracing, perf counters) to diagnose GC pauses, compilation stalls, safepoints, and contention.
- Mentor and coach engineers; cultivate a culture of rigorous design, empirical validation, and respectful collaboration.
- Contribute to roadmap planning, risk management, and release criteria; communicate trade‑offs to stakeholders.
Required Qualifications
- 10+ years of systems‑level software development with deep expertise in C and C++ (performance, memory safety, concurrency).
- Strong knowledge of virtual machine internals: runtime services, class/method metadata, bytecode/IR pipelines, safepoints, deoptimization, inline caches.
- Familiarity with compilers (JIT and/or AOT): IR design, code generation, register allocation, inlining, tiering, and optimization passes.
- Solid understanding of operating systems (Linux preferred): processes/threads, scheduling, memory management (NUMA, huge pages), filesystems, networking.
- Working knowledge of computer architecture and hardware performance: caches, TLB, branch prediction, SIMD, PMU/perf tooling.
- Proven ability to design clean, scalable architectures and write high‑quality design docs; expertise in API/ABI boundaries and componentization.
- Comfort with performance analysis tools: perf, eBPF, VTune, flame graphs, micro‑benchmarks; methodical approach to measurement and regression control.
- Excellent problem‑solving and debugging skills for complex, concurrent systems.
- Clear communication, cross‑team collaboration, and ability to lead technical initiatives.
Preferred Qualifications
- Experience with managed runtimes (e.g., JVM, CLR, LuaJIT, WebAssembly engines) or building custom VMs.
- Knowledge of modern GC strategies (region/mark‑copy, concurrent, pauseless techniques) and memory allocators.
- Background in low‑latency systems for trading, telco, gaming, or real‑time analytics.
- Experience with tiered compilation, profile‑guided optimization (PGO), AOT caches, and startup/warm‑up optimization.
- Exposure to kernel development, drivers, or firmware; familiarity with RT kernels or scheduler tuning.
- Contributions to open‑source compiler/runtime projects or published performance work.
Ways of Working
- Positive, can‑do attitude with ownership mindset and bias for action.
- Team‑first collaborator who values transparency, constructive feedback, and knowledge sharing.
- Pragmatic engineering: balance theoretical rigor with practical deliverables and measurable impact.
- High bar for quality and security; advocate for testing, benchmarking, and reproducibility.
We Offer
- Equity Program - be part of the company success.
- Annual bonus based on company performance.
- Referral Program - bring your colleague we would all love to work with.
- IT Equipment - MacBook Pro or any other HW according to your preferences.
- Work-life balance - 5 weeks of holidays, 5 sick days, flexible working hours, 100% work from home also possible.
- Offices in Prague City Centre - if you prefer.
- Most importantly you will work with top experts worldwide who contribute to the Java ecosystem
