Senior Full-Stack Engineer: Kotlin/React, AI-Driven

OpenKrill; United States; Hybrid; USD 101,000 - 146,000; Full time

Benefits offered by this job

Stock options

Unlimited PTO

Health insurance for family

Transit reimbursement

Hybrid work model

Paris office

Remote work allowance

39-hour workweek

Job summary

Ussunday, headquartered in Paris, seeks a Senior Software Engineer to deliver full-stack features in Kotlin and React, leveraging AI agents to accelerate development. You will own complex topics from architecture to reliability and contribute to scalable services handling high loads.

The role requires hands-on experience with Kotlin backend and React frontend, production deployments, and fluent FR/EN communication. The position offers a hybrid work model based in Paris with generous benefits.

Qualifications

• Proven full-stack development with Kotlin on backend and React.js on frontend.
• Experience deploying high-load services in production.
• Hands-on experience with AI agents or AI-assisted tooling.
• Ability to reason about architecture, reliability, and trade-offs.
• Strong business sense and prioritization skills.
• Fluency in French and English (spoken and written).

Responsibilities

• Design and deliver high-quality full-stack features from Kotlin backend services to React.js frontend applications.
• Write code using AI agents and help build an agentic software factory.
• Own complex topics related to software design, architecture, and service reliability.
• Design scalable production-ready solutions.
• Improve development practices and engineering efficiency through agentic AI.
• Make pragmatic technical decisions considering business impact, simplicity, and speed.
• Share standards and learnings to help the team grow.

Skills

Kotlin backend

React.js frontend

AI agents

System architecture

Production scale

Bilingual FR/EN

Job description

Ussunday, headquartered in Paris, seeks a Senior Software Engineer to deliver full-stack features in Kotlin and React, leveraging AI agents to accelerate development. You will own complex topics from architecture to reliability and contribute to scalable services handling high loads.

The role requires hands-on experience with Kotlin backend and React frontend, production deployments, and fluent FR/EN communication. The position offers a hybrid work model based in Paris with generous benefits.