Senior Compiler Performance Engineer (Java/LLVM)

Location: Prague, Belgrade, Serbia, Cyprus, Limassol, Toronto, Canada, or the United States. Hybrid and full-remote work options are available depending on location.

Company

hirify.global develops Java platform technologies for modern cloud enterprises and contributes to the Java and OpenJDK ecosystem.

What you will do

• Own Falcon performance for selected workloads or optimization areas from analysis through implementation and validation.
• Design and implement optimizations in the compiler middle end and back end, including inlining, loop optimization, vectorization, escape analysis, speculation, deoptimization, GC barriers, and runtime calls.
• Improve code generation quality for x86_64 and AArch64 and help bring Falcon to new hardware platforms.
• Investigate complex customer performance issues and convert findings into compiler improvements.
• Review code, mentor engineers, and improve performance methodology across the team.

Requirements

• 5+ years of professional experience developing optimizing compilers or JIT compilers.
• Strong C++ design and coding skills in large codebases.
• Proven experience delivering compiler optimizations with measurable performance impact.
• Deep knowledge of compiler optimization theory and tradeoffs involving compile time, code size, and correctness.
• Strong performance analysis skills, including profilers, hardware counters, and generated assembly.

Nice to have

• Experience with LLVM optimization passes or code generation; LLVM commit access is a plus.
• Experience with managed-language JIT compilers such as HotSpot C2, Graal, V8, or .NET RyuJIT.
• Deep knowledge of x86_64 or AArch64 microarchitecture.
• Experience with JVM internals, including garbage collection, deoptimization, and profiling.
• PhD in Computer Science or significant compiler research experience.

Culture & Benefits

• Work with compiler experts contributing to the Java ecosystem.
• Flexible working hours.
• Premium IT equipment, including a MacBook Pro or hardware of choice.
• Five weeks of holidays and five sick days.
• Referral program and opportunities to work from Prague, Limassol, or Belgrade offices.