Fullstack Engineer

Role Description

As a Fullstack Engineer at Oneleet, you'll work across our entire stack to ship features that make our cybersecurity platform fast, reliable, and genuinely useful for security teams. You'll own features end-to-end — from backend services and APIs through to the UI components that customers interact with day-to-day.

This is a hands-on engineering role at a Series A startup. You'll work closely with backend engineers, AppSec, design, and product to take features from mock-up to shipped product, and you'll engage directly with customers to iterate based on real-world usage.

Working primarily in Go, TypeScript, and React, you'll help us ship fast without sacrificing reliability or design quality.

Key Responsibilities

• Build features end-to-end across backend (Go) and frontend (React/TypeScript)
• Design and implement APIs that power dashboards, workflows, and reporting
• Build UI components that present complex data clearly and drive user action
• Map complex backend data to clear, actionable interfaces
• Implement robust error handling and fallback behaviors for upstream service failures
• Optimize end-to-end performance, including caching, pagination, and query design for high-volume data
• Develop reusable patterns and components that scale across many areas of the platform
• Work directly with customers and design partners to understand how features are used and iterate rapidly
• Build monitoring and analytics to track feature usage, success rates, and user engagement
• Collaborate with AppSec, backend, and design on how data flows from services through to the UI

Qualifications

• 5+ years of fullstack software development experience with expertise in Go and JavaScript/TypeScript
• Strong experience building production APIs (REST and/or gRPC) and integrating with third-party services
• Proven track record of building responsive, intuitive user interfaces with modern JavaScript frameworks (React preferred)
• Experience with data transformation and mapping between different system formats
• Strong understanding of asynchronous programming patterns and API optimization techniques
• Solid debugging skills across the full stack — from backend services to frontend UI
• Experience with production monitoring, logging, and observability tools
• Experience gathering requirements from users and translating feedback into technical improvements
• Strong communication skills and comfort working directly with customers
• Ability to balance technical excellence with shipping features that provide immediate value

Bonus

• Background in cybersecurity or security tools
• Experience building data visualization components
• Experience with workflow engines and async job orchestration

Benefits

• Comprehensive health & wellness benefits
• 20 days PTO per year, plus 8 floating holidays
• Remote work culture
• Team off-sites in stunning places (Amsterdam, Italy, etc.)
• Competitive compensation & equity