Nikolas Iv

Delivered web applications, backend services, Telegram bots / Mini Apps and automation products for client projects in fintech, AI SaaS, e-commerce, travel, fitness and expert services. Designed REST APIs, async backends, data-processing flows, payment scenarios, onboarding flows, API access management and operational tooling. Integrated AI providers, LLM gateways, billing, subscriptions, rate limiting, usage tracking, payment systems, external APIs and internal workflows. Handled product logic, technical planning, implementation, deployment with Docker / Nginx, production support and post-launch iteration.

Developed a data collection and preparation module for the backend layer of an AI service; integrated message processing into the main pipeline and improved data-processing stability.

Analyzed requirements and implemented backend logic for an expert-services solution; built template-based document generation from user data and supported the product after launch. Reduced document preparation time from one business day to approximately 7 minutes.