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Azul is the company focused 100% on Java, building the Java platform for the modern cloud enterprise. Falcon is the optimizing just-in-time (JIT) compiler in Azul Platform Prime, built on LLVM, that compiles hot Java bytecode into highly optimized machine code. The compiler is mature and runs in production at large enterprises.
You will be the senior technical voice on a distributed team of compiler experts, setting the technical direction for Falcon performance. You will decide where the next significant performance gains come from, lead the design of optimizations that deliver them, and ensure the compiler architecture supports the product roadmap. You will partner closely with runtime, garbage collection, and product teams.
Key responsibilities:
- Own performance of Falcon for a set of workloads or optimization area end-to-end: analysis, design, implementation, and validation
- Design and implement new optimizations and improve existing ones in the middle end and back end, including inlining heuristics, loop optimizations, vectorization, escape analysis, speculation and deoptimization, and GC barrier and runtime call optimization
- Drive code generation quality on x86_64 and AArch64, including bringing Falcon to new hardware platforms
- Investigate complex performance issues reported by customers and translate findings into compiler improvements
- Review code, mentor engineers on the team, and raise the bar for performance methodology
The role offers flexible working hours, choice of Prague, Limassol, or Belgrade city center offices with hybrid/full-remote options, premium IT equipment, 5 weeks of holidays plus 5 sick days, and competitive compensation.
Requirements:
- 5+ years of professional experience developing optimizing compilers or JIT compilers
- Strong C++ design and coding skills in large codebases
- Proven track record of delivering compiler optimizations with measurable performance impact
- Deep knowledge of compiler optimization theory and its practical tradeoffs: compile time, code size, correctness
- Strong performance analysis skills: profilers, hardware counters, reading and reasoning about generated assembly
Nice to have:
- Significant experience with LLVM optimization passes or code generation; LLVM commit access is a plus
- Experience with JIT compilers for managed languages: HotSpot C2, Graal, V8, .NET RyuJIT or similar
- Deep knowledge of x86_64 and/or AArch64 microarchitecture
- Experience with JVM internals: garbage collection, deoptimization, profiling
- PhD in Computer Science or significant research experience in compilers
