Node.js Backend Developer

United Tech is a global IT product company shaping the future of real-time social connection. With millions of users across North America, Europe, LATAM, and MENA, we build next-gen mobile and web apps for live-streaming and social networking. Our platforms enable connection at scale — fast, interactive, and deeply engaging. The market is projected to exceed $206B by 2030, and we are already leading the evolution. Founded in Ukraine, scaling worldwide. About the role: We're looking for a Middle Node.js Backend Developer to join the backend team. You'll be building the infrastructure that powers revenue and growth — from web billing integrations with payment providers to server-side marketing pipelines that fuel acquisition. If you thrive in high-load, product-driven environments where your code ships to real users and directly impacts the bottom line, this role was made for you. In this role, you will Develop and ship web billing integrations: payment providers, subscriptions, recurring billing, webhook handling (idempotency, retries, reconciliation) Develop and ship marketing integrations: attribution platforms, server-side conversion/events APIs, analytics and CRM/ESP pipelines Create technical designs for product epics and decompose them into actionable tasks Participate in team processes: grooming, sprint planning, estimations Run investigations and tech research (3rd-party API limits, provider selection, edge cases) Address tech debt and improve reliability and observability of integrations Take part in the full SDLC: design, dev, code review, testing, release, support It's all about you 3+ years of commercial backend development experience 2.5+ years with Node.js (TypeScript) Solid experience with relational and non-relational databases (PostgreSQL, MongoDB, Redis) Experience with SOA/microservices: inter-service communication and dev process Strong fundamentals in design principles and patterns (SOLID, event-driven) Experience integrating third-party REST APIs: auth, rate limits, retries, webhooks, idempotency Experience with async processing / message queues (BullMQ, RabbitMQ or Kafka) Experience with a cloud provider (AWS / GCP) Understanding of scaling and high-load systems Daily use of AI coding assistants (Claude Code, Cursor, GitHub Copilot) for development, refactoring, tests, and documentation Ability to write effective prompts and review/validate AI-generated code — quality and security ownership stays with you Would be a plus Hands-on web billing / payment integrations (Stripe, Paddle, Solidgate, Recurly, Braintree, PayPal) and subscription/recurring-billing logic Payments domain knowledge: 3DS, PCI-DSS basics, chargebacks/fraud, dunning, reconciliation Marketing/growth integrations: AppsFlyer/Adjust, Meta CAPI, Google/TikTok events APIs, S2S postbacks Experience with analytics/event pipelines and CRM/ESP tools DDD / CQRS, WebSockets (ws, socket.io) Understanding of how to integrate LLM APIs into product features What we offer Care and support: 20 paid vacation days, 15 sick days, and 6 additional days off for family events Up to 10 additional days off for public holidays 100% medical insurance coverage Sports and equipment reimbursement Team building events, corporate gifts, and stylish merch Financial and legal support Maternity recovery support allowance Position retention and support for those who join the Armed Forces of Ukraine Participation in social initiatives supporting Ukraine Comfortable working environment: Work from our Kyiv hub or remotely with a flexible schedule Modern equipment or depreciation of your own tools Investment in your future: Collaborate with a highly-skilled team of Middle & Senior professionals, sharing practical cases and expertise in the social networking niche 70% of our heads and leads have grown into their roles here – so can you! Performance-oriented reviews and Individual Development Plans (IDPs) Reimbursement for professional courses and English classes Corporate library, book club, and knowledge-sharing events Hiring process Intro call Pre-screen Technical interview Final Interview Reference check Offer