Language Engineer – Compiler & Programming Languages | Fast-Growing AI & Cloud Data Transformation Company

We are currently partnering with a fast-growing AI & Data consulting company in Japan that is actively expanding its AI & Data division and is now looking for a Language Engineer specializing in Programming Languages Compiler Technologies and Program Analysis.

Please note that prior financial industry experience is NOT required.

Annual Salary: 10M 22M JPY

JAPANESE BUSINESS LEVEL REQUIRED

The company works directly with major financial institutions and enterprise clients in Japan supporting large-scale digital transformation AI implementation data modernization and legacy system transformation initiatives.

This position is part of the development team behind a proprietary AI-powered legacy modernization product designed to help financial institutions analyze understand and modernize large-scale legacy systems.

Financial institutions often operate complex core systems built over multiple generations using programming languages such as COBOL PL/I Java C/C SQL and Shell. The company is now developing a language-independent analysis and transformation platform capable of handling these complex multilingual codebases at scale.

As a Language Engineer you will play a core technical role in designing and implementing the programming language infrastructure behind this platform including parsers Abstract Syntax Trees (AST) Control Flow Graphs (CFG) Intermediate Representations (IR) static analysis systems and cross-language code transformation technologies.

You will also contribute to the technical foundation that enables Large Language Models (LLMs) and other AI technologies to understand analyze and transform complex enterprise source code.

The environment is highly technical and collaborative working closely with Software Engineers Product Managers AI specialists and consultants.

This is an excellent opportunity for engineers who want to work on deep technical challenges at the intersection of Programming Languages Compiler Technologies Program Analysis Legacy Modernization and Generative AI.

Rather than focusing on a single programming language this role offers the opportunity to build the core technology for a language-independent modernization platform capable of analyzing and transforming large-scale mission-critical enterprise systems.

Key Responsibilities

Design and implement multilingual source-code analysis infrastructure

Design and develop parsers for multiple programming languages

Design Abstract Syntax Trees (AST) Control Flow Graphs (CFG) and Intermediate

Representations (IR)

Develop language-independent program analysis frameworks

Design and implement static analysis and structural code analysis capabilities

Build call graph dependency analysis and code relationship analysis systems

Develop abstractions and visualization mechanisms for large-scale legacy codebases

Design validation mechanisms to ensure consistency before and after code transformation

Develop cross-language code transformation engines

Implement automated refactoring and source-code transformation capabilities

Design language infrastructure enabling AI/LLM-based code understanding and generation

Contribute to architecture design for AI-integrated legacy modernization platforms

Collaborate with engineers Product Managers and consultants on product development and technical strategy

Examples of Technical Challenges

Analyzing large-scale financial systems containing COBOL PL/I Java C/C SQL Shell and other languages

Building multilingual parsing infrastructure from the ground up

Designing language-independent AST / IR architectures

Implementing scalable static analysis and dependency analysis systems

Developing automated legacy code transformation and refactoring technologies

Building compiler and program-analysis technologies as part of a commercial product

Integrating LLMs with structured source-code analysis systems

Developing scalable modernization infrastructure for mission-critical enterprise systems

Requirements

Required:

Professional experience in programming language processing such as Parser development AST manipulation static analysis or code transformation

Experience designing or implementing systems using Abstract Syntax Trees (AST) and/or Intermediate Representations (IR)

Strong understanding of the syntax and type systems of multiple programming languages

Experience analyzing refactoring or transforming large-scale codebases

Ability to clearly communicate technical design concepts and discuss architecture and implementation approaches with other engineers

Benefits

Compensation & Work Style:

Annual salary: 10M 22M JPY

Location: Nihonbashi Chuo-ku Tokyo

Hybrid work style available (office remote work combination)

Full flex-time system with no core hours

Standard working hours: 8 hours/day

Average overtime: approximately 2030 hours/month

Salary review available

Performance-based bonus generally paid twice per year (June and December)

Holidays & Time Off:

Full two-day weekend system

123 annual holidays

Paid leave granted after the probation period

Refresh leave

New Year holidays

Parental leave

Condolence leave

Benefits:

Defined contribution pension plan

Learning and self-development support

Internal/external networking support budget

Sports & wellness allowance

Annual health check support

Full influenza vaccination support including dependents

Full transportation reimbursement

Relocation support for eligible employees

Childcare/babysitter support

Business trip and training allowances