Principal Software Engineer (React + Node) – Remote -EU or USA

We are looking for a Principal Software Engineer, who will be the technical authority, responsible for all development, architecture decisions, and long-term technical strategy across a website, mobile app, and ML-powered ad-tech optimization systems.

This is a full-time independent contractor engagement. You will work hands-on at a senior level where site speed and server performance are core success metrics. You will work directly with stakeholders to set technical direction, remove bottlenecks, and ship production-grade code.

Engagement Details:
• Type: Full-time independent contractor or EOR
• Hours: Full-time commitment expected
• Location: Remote
• Clients: US and Europe
• Rate: Competitive, based on experience

What You’ll Own
• End-to-end technical ownership of a high-revenue web platform and mobile app
• Architecture design and long-term technical strategy
• Server-side rendering pipeline using Node.js, Fastify 5, and React 19
• Data layer across MySQL and BigQuery
• GCP infrastructure including Cloud Run, Cloud Build, and Global Load Balancer
• Ad-tech integrations including Google Ad Manager, GTM, GTag, and GPT.js
• Performance optimization at scale, where every millisecond counts
• ML pipeline maintenance and optimization for ad-tech performance

Requirements

Must-Have Qualifications

These are non-negotiable. Please only apply if you have strong, production-proven experience in all of the following:
• Node.js with TypeScript in production
• React in a server-side rendering context
• MySQL including database design, query optimization, and ORM usage
• BigQuery for querying and managing large-scale datasets
• GCP with hands-on experience in Cloud Run, Cloud Build, Cloud SQL, and Load Balancing. GCP certification is a significant bonus.

Nice-to-Have Experience
• Ad-tech industry experience including ad serving, yield optimization, and programmatic advertising
• Affiliate marketing experience, particularly with Anura and Everflow
• Cloudflare including CDN configuration, caching strategies, and Workers
• Fastify, especially Fastify 5 patterns
• Flutter for mobile app contribution
• Golang or Rust for high-performance service work
• Machine learning applied to ad-tech optimization (not LLMs or agents)
• Experience in DeFi, crypto, NFT, blockchain, fintech, or healthcare verticals

Benefits
• Fully remote work
• Flexible hours
• Paid vacation and sick days

Application Process
• We do not review applications via LinkedIn DMs or email. Please apply through the application link.
• We do not work with staffing agencies or third-party recruiters. Direct applicants only.

Location: , ,

Salary: 120000 – 150000

Ladders: Apply Here