Senior Backend Engineer (Node.js)

TL;DR

Senior Backend Engineer (Node.js): Architecting and implementing ad-serving infrastructure for real-time bidding and high-performance APIs with an accent on latency optimization, database performance, and scalability. Focus on designing caching layers, query optimization, third-party integrations, and A/B testing systems for revenue tracking and analytics.

Ukraine, Poland, Remote

Company

Global digital services company specializing in software solutions for Supply Chain, Healthtech, Collaboration Tech, and Gaming. Recognized as a top outsourcing provider and for employee engagement.

What you will do

• Build core systems and ad-serving infrastructure for real-time bidding (RTB).
• Design high-performance APIs with strict latency and throughput requirements.
• Implement revenue tracking, analytics systems, database migrations, and caching strategies.
• Integrate with e-commerce and ad-tech partners via REST, webhooks, and third-party services.
• Develop internal tools, automation workflows, and A/B testing infrastructure.
• Work directly with founders and product team to shape architecture and mentor juniors.

Requirements

• 5+ years of backend development experience, preferably Node.js or TypeScript.
• Strong PostgreSQL knowledge, including query optimization, indexing, and migrations.
• Production experience with cloud infrastructure, ideally AWS.
• API design experience including REST, webhooks, and third-party integrations.
• Ownership mindset to identify and solve problems.
• Systems thinking across databases, caches, queues, and services.

Nice to have

• Ad-tech experience such as RTB, DSPs, attribution, or affiliate marketing.
• Data engineering experience including ETL pipelines or Snowflake.
• Experience with KeystoneJS, Prisma, PostgreSQL, AWS ECS.

Culture & Benefits

• Flexible hours and remote-first mode with hybrid teams; work from home, office, or anywhere.
• Competitive compensation and complete hardware/software setup.
• Health insurance, vacation, sick leaves, holidays, paid maternity/paternity leave.
• Learning & development: workshops, webinars, English classes, global certifications (AWS, etc.), Udemy/Pluralsight.
• Open-door culture, transparent communication, team buildings, mentorship, and individual development plans.