Top Software Engineer Jobs in Japan

Leads the design, development, and operation of high-performance Linux platforms supporting low-latency electronic trading. Responsibilities include kernel and hardware performance tuning, infrastructure automation, containerization, CI/CD, infrastructure as code, networking optimization, AI-assisted engineering governance, vendor collaboration, and technical leadership. The role mentors engineering teams, drives platform reliability and scalability, and governs engineering decisions across electronic trading infrastructure.

Leads technical discussions and requirements clarification with Japanese customers, bridges requirements to offshore development teams, and contributes across software design, development, testing, and delivery. Applies AI and generative AI to improve SDLC activities, while supporting system migration and legacy modernization initiatives. The role requires business-level Japanese and Vietnamese proficiency, substantial software development experience, and onsite work in Kyushu, Japan.

The Software Engineer will design, develop, and maintain robust APIs, oversee backend API performance, and collaborate with cross-functional teams to align architecture with product strategy.

The Forward Deployed Software Engineer designs and implements data-driven solutions for clients, collaborating with diverse teams to tackle complex problems and drive impactful results.

Build, operate, and enhance low-latency Python applications supporting Rates trading desks with real-time risk, PnL, and decision-support capabilities. Responsibilities include production support, troubleshooting, system design, performance optimization, monitoring, incident response, and delivery of resilient services. The role partners closely with traders, leads technical initiatives, mentors engineers, and promotes secure, responsible use of AI-assisted development tools.

The Software Engineer role involves designing, developing, and maintaining backend services, optimizing APIs, and collaborating with cross-functional teams for enterprise solutions.

The Senior Full-Stack Software Engineer will design and develop full-stack cloud services for enterprise clients, ensuring code quality and potentially mentoring a small team.

Lead backend design and development for a mobile-first strategy-building fintech: build scalable Python/FastAPI services, real-time APIs/WebSockets, integrate market data providers, optimize performance across large datasets and simulations, contribute front-end React/TypeScript work, maintain containerized deployments and CI/CD pipelines, and document and collaborate in an async-first team.

Participate in developing and maintaining core products, implementing business-module interface documentation, troubleshooting QA-reported issues, and supporting customer-service teams with problem resolution and system improvements. The role requires Java and Spring microservices knowledge, database and middleware experience, strong communication skills, and collaboration in a global blockchain environment.

Participate in developing and maintaining core products, compiling business-module interface documentation, troubleshooting issues identified by QA, and assisting customer support with problem resolution and system improvements. The role requires Java and Spring microservices knowledge, database and middleware familiarity, strong communication, teamwork, and logical problem-solving skills.

Supports the full software quality lifecycle, including requirements analysis, test design, manual and automated testing, defect management, and reporting. Develops automated tests using Selenium or Playwright and integrates them with CI/CD pipelines and cloud platforms. Serves as an English-Japanese communication bridge across onshore and offshore teams, participates in Agile ceremonies, and applies AI, agentic workflows, prompt engineering, Copilot, and RAG to improve test coverage, defect analysis, and delivery efficiency.

Design, build, and maintain backend services and reliability tooling to improve availability and resiliency. Implement CI/CD, infrastructure-as-code, observability (SLIs/SLOs/telemetry), incident management, and automation to reduce toil and drive measurable reliability improvements.

Designs and develops blockchain security products, core frameworks, APIs, infrastructure, and automation for large-scale distributed systems. Responsibilities include architecture standards, performance tuning, incident troubleshooting, system refactoring, continuous delivery, capacity management, and reusable libraries. The role also engages users, coordinates with cross-functional teams, and addresses security risks involving blockchain, smart contracts, wallets, and on-chain attacks.

Develop and optimize backend microservices for a high-scale global payments network using Go, PostgreSQL, and Kafka. Design distributed systems for secure, reliable, low-latency financial transactions; collaborate on architecture, testing, monitoring, fraud detection, compliance, and risk mitigation. Build internal tools, support frontend efforts, and work cross-functionally to deliver scalable financial products in a fast-paced environment.

Customer-embedded principal engineer who designs, builds, and ships production-grade solutions, translates business needs into technical approaches, influences senior stakeholders, and transitions work to FDE teams to deliver measurable outcomes.

Participate in developing and maintaining core products, compiling business-module interface documentation, troubleshooting issues identified by QA, and helping Customer Support resolve and categorize customer problems. The role is part of a 3–6 month early-career accelerator internship focused on blockchain and digital assets. Candidates should have strong Java, Spring microservices, database, middleware, communication, teamwork, and problem-solving skills.

Participate in developing and maintaining core products, documenting business interfaces, troubleshooting issues identified by QA, and supporting customer-service teams with problem resolution and system improvements. The role requires Java development, Spring microservices, database and middleware knowledge, strong communication, teamwork, and learning ability. Experience with Web3 projects is preferred.

Lead technical design and delivery of API-driven, cloud-native integration solutions. Translate business requirements into scalable architectures, perform code reviews, mentor engineers, support production issues, and apply AI-assisted engineering practices to improve productivity and solution quality.

Lead architecture, modernization, and delivery of enterprise Direct Marketing digital platforms. Drive end-to-end full stack engineering, remain hands-on in coding and troubleshooting, and lead AI/Generative AI initiatives from PoC to production. Partner with stakeholders to convert business needs into scalable, secure solutions supporting customers, agencies, partners, call centers, and internal users.

Develop and validate mission-critical spacecraft flight software in C/C++, Python, and Java. Responsibilities include software design, coding, unit and integration testing, simulation-based verification, issue resolution, documentation, and subsystem integration. Improve CI/CD pipelines, containerized development environments, testing automation, and spacecraft simulation models. Collaborate with subsystem teams to clarify requirements and advance verification tasks. Knowledge of spacecraft control systems, AOCS, GNC, or FDIR is advantageous.

The Software Engineer will design and maintain backend APIs, oversee the API landscape, and collaborate with cross-functional teams on B2B solutions for Speechify's platform.

The Software Engineer will design and maintain backend APIs for Speechify’s services, collaborate on B2B solutions, and optimize performance.

Build and execute automated tests for enterprise web applications and APIs. Extend automation frameworks, develop configurable testing tools, simulate high transaction volumes, execute performance tests, document and verify defects, and collaborate with product engineers on testability. The role also involves analyzing technical solutions, researching testing technologies, supporting users, and preparing formal test plans, datasets, and configurations.

Build and scale high-performance backend systems for SmartNews’s advertising platform. Responsibilities include architectural design, ad ranking and delivery, premium ads, targeting, custom audiences, measurement, and resilient online and offline services. Collaborate with machine learning, data platform, ads foundation, and AI infrastructure teams. The role requires developing high-traffic web services, optimizing low-latency systems, contributing to microservice architectures, and partnering with product stakeholders throughout the project lifecycle.

Develop and localize autonomous-driving software for Japan by bringing up and validating AI software stacks on customer hardware. Port Linux, QNX, and Adaptive AUTOSAR systems; integrate drivers, middleware, boot configurations, diagnostics, logging, and secure boot. Collaborate with verification, release, OEM, and Tier 1 teams to resolve hardware integration issues. Automate flashing, setup, health checks, and target-hardware testing while integrating platforms into CI/CD, HIL, and test infrastructure.