Compiler Performance Engineer

Azul; Bengaluru; On-site; INR 3,000,000 - 6,000,000; Full time

Job summary

Azul's Falcon is the optimizing just-in-time (JIT) compiler in Azul Platform Prime. It translates hot Java bytecode into highly optimized machine code and is built on LLVM.

We are looking for a Compiler Performance Engineer to identify slow code in generated output, fix it in the optimizer and code generator, and drive measurable performance improvements on real workloads across large enterprises. Join a distributed team of compiler experts and impact customer performance at scale.

Qualifications

• 2+ years of professional experience in compilers, JIT compilers or low-level performance engineering.
• Strong C++ design and coding skills.
• Solid understanding of SSA, data-flow analysis and loop transformations.
• Ability to read assembly and reason about performance differences.

Responsibilities

• Analyze performance of Java workloads and trace slow code paths to the optimizer.
• Implement and improve optimizations in Falcon's middle-end and back end.
• Improve code generation for x86_64 and AArch64.
• Write tests and benchmarks to prove improvements and prevent regressions.
• Collaborate with LLVM upstream where it makes sense.

Skills

Compiler experience

C++

Compiler optimization theory

Reading assembly

Education

MSc or PhD in Computer Science with a compiler focus

Tools

LLVM

Profilers

x86_64 / AArch64 knowledge

JVM internals

Job description

Falcon is the optimizing just in time (JIT) compiler in Azul Platform Prime. It compiles hot Java bytecode into highly optimized machine code and delivers Java performance that standard JVMs do not reach. Falcon is built on LLVM.

We are looking for a Compiler Performance Engineer to make Falcon generate even faster code. This is not a compiler front end role and not a compiler built from scratch: the compiler exists, runs in production at large enterprises, and your job is to find where the generated code is slower than it should be and fix it in the optimizer and code generator.

You will join a distributed team of compiler experts and work on real workloads with direct, measurable impact on customer performance.

What You Will Do (aka Responsibilities)

• Analyze performance of Java benchmarks and customer workloads, find gaps in generated code and trace them to their root cause in the compiler
• Implement and improve optimizations in Falcon's middle end and back end: inlining, loop optimizations, vectorization, redundancy elimination, speculative optimizations and their interaction with the runtime
• Improve code generation for x86_64 and AArch64
• Write tests and benchmarks that prove the improvement and protect it from regressions
• Contribute changes upstream to LLVM where it makes sense

What You'll Bring (Experience, Skills)

• 2+ years of professional experience in compilers, JIT compilers or low level performance engineering
• Strong C++ design and coding skills
• Solid understanding of compiler optimization theory: SSA, data flow analysis, loop transformations
• Ability to read assembly and reason about why one instruction sequence is faster than another

Very Nice to Have

• Experience with LLVM IR and LLVM optimization passes, or with another optimizing compiler such as HotSpot C2, Graal, GCC or V8
• Experience with profilers such as perf, VTune or async profiler
• Knowledge of x86_64 and/or AArch64 microarchitecture
• Experience with Java, Scala or Kotlin, or with JVM internals
• MSc or PhD in Computer Science with a compiler or performance focus

We may use artificial intelligence (AI) tools to support parts of the hiring process, such as reviewing applications, analyzing resumes, or assessing responses and identifying potential inconsistencies or verification signals in application materials based on available information. These tools assist our recruitment team but do not replace human judgment. Final hiring decisions are ultimately made by humans. If you would like more information about how your data is processed, please contact us.