Staff Software Engineer - Virtual Machine, Czech Republic

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