4BBCorp

Who We Are

JIG-SAW operates 24/7 Operations Centers in Japan and Canada that proactively monitor systems, issue alerts, and deliver live incident response—keeping your web services and IoT environments secure and running smoothly.

JIG-SAW Inc. (Tokyo Stock Exchange: 3914)

Corporate site — https://jig-saw.com/en/
NEQTO.ai — https://neqto.ai/

About the Role

Join us to build a game-changing, AI-driven IoT platform that ingests millions of sensor events, derives real-time insights, and powers mission-critical workflows for enterprise customers. As a Senior Backend Engineer, you’ll own core services end-to-end—from secure, multi-tenant APIs (auth, RBAC, billing) and high-throughput data ingestion (MQTT → time-series pipelines) to the reliability layer (observability, rate limiting, caching, retries, idempotency). You’ll shape data models across PostgreSQL + Prisma and MongoDB, define clear API contracts and performance SLAs with Frontend/AI teams, and raise the bar through testing, code reviews, and CI/CD. If you enjoy tackling hard performance problems, designing for scale, and turning ambiguous requirements into elegant systems, you’ll feel right at home here.

Application Requirements

• Education: Bachelor’s degree or higher in Computer Science (or closely related field) is required.
• Portfolio required: Please include links to your GitHub/GitLab, product sites, demos, or case studies. Applications without a portfolio will not be considered.
• Programming assessment: Candidates must pass a third-party programming service assessment as part of the screening process.

Required Skills

• Node.js 20 or later
• TypeScript 5
• Express 5
• Authentication/Authorization (JWT, OAuth2)
• PostgreSQL + Prisma 6
• MongoDB 6 or later

Nice-to-Have

• Generative AI (OpenAI, Anthropic Claude, Google Gemini), LangChain, agents, vector databases for RAG, prompt engineering
• WebSocket
• IoT (e.g., sensor/time-series pipelines, MQTT ingestion)
• REST API design (swagger-jsdoc + swagger-ui-express)

Experience Guideline

• 5+ years of professional experience with Node.js, TypeScript, PostgreSQL, and MongoDB

Compensation & Benefits

• Competitive salary (market-based; location-dependent)
• Health, Dental, Vision insurance (U.S.)
• Paid Time Off (PTO): vacation, sick leave, company holidays
• Remote work

Job Type: Full-time

Pay: $100,000.00 - $150,000.00 per year

Benefits:

• Dental insurance
• Health insurance
• Paid time off
• Vision insurance

Education:

• Bachelor's (Required)

Experience:

• professional-level PostgreSQL: 5 years (Required)
• professional-level MongoDB: 5 years (Required)
• professional-level Node.js, TypeScript, Express: 5 years (Required)

Work Location: Remote