Senior Software Engineer

Svitla Systems Inc. is looking for a Senior Software Engineer (Node.js) for a full-time position (40 hours per week) in Europe. Our client is a software company providing a B2C ecommerce identity and marketing data platform. Role Overview: The team is seeking a Senior Software Engineer to own and evolve our API gateway and tracking layer, with a strong focus on JavaScript-based event pipelines, pixel technologies, and Lua-powered gateway extensions using API7 / Apache APISIX.This role is critical to ensuring accurate, low-latency site tracking, reliable event ingestion, and high-fidelity telemetry across browser, server, and API boundaries. Occasional travel to Vienna is a must-have option. Requirements: • 5+ years of experience in platform, backend, or tracking-focused engineering roles. • Strong experience with JavaScript / Node.js in production systems. • Proven experience designing/operating an API gateway or edge layer (core responsibility, not incidental). • Lua development in NGINX / OpenResty / APISIX-style environments (plugins/middleware). • Experience with high-volume, low-latency event ingestion and/or request routing. • Experience designing and operating pixel-based tracking systems. • Solid understanding of browser internals, HTTP, cookies, CORS, and security. • Familiarity with cloud-native infrastructure (AWS/GCP, Kubernetes). • Excellent spoken and written English. Nice to have: • Experience with CDPs, analytics platforms, or attribution systems. • Server-side tagging or GTM Server-Side experience. • Knowledge of privacy frameworks (consent, first-party data strategies). • OpenTelemetry or real-time streaming pipelines. Responsibilities: • Design and operate an API7 / Apache APISIX gateway layer for high-volume tracking and event ingestion. • Develop custom Lua plugins to: Capture, normalize, and enrich pixel and API events; Perform edge-side validation, filtering, and routing. • Build and maintain JavaScript / Node.js services that: Receive and process tracking events; Support pixel endpoints, event batching, and retries; Interface with downstream analytics and data platforms. • Instrument tracking pipelines with observability tooling (OpenTelemetry, Prometheus, Grafana, ELK, SumoLogic). • Ensure compliance and reliability across tracking infrastructure (latency, completeness, uptime). • Partner with product, data, and privacy teams to evolve tracking strategies. • Participate in on-call rotations, incident response, and postmortems. • Implement and maintain pixel-based tracking systems, including: First-party and third-party pixel architectures; Cookie and localStorage handling; Browser-to-server event flows. We offer: • US and EU projects based on advanced technologies. • Competitive compensation based on skills and experience. • Regular performance appraisals to support your growth. • Flexibility in workspace, either remote or our welcoming office. • Bonuses for article writing, public talks, and other activities. • Generous time off, including vacation, national holidays, sick leaves, and family days. • Personalized learning programs tailored to your interests and skill development. • Free tech webinars and meetups organized by Svitla. • Regular corporate online activities. • Awesome team and a friendly, supportive community!