Lucas – Python, React, Typescript

A multi-tenant B2B SaaS platform built for construction material retailers, focused on automating the quotation process through WhatsApp conversational workflows. The system manages dynamic pricing rules, calculates freight costs based on ZIP codes, and applies payment-method-specific discounts. The solution was developed to replace manual quote handling and streamline operations for traditionally offline retail businesses, reducing operational friction and improving response speed to customer requests.

• Designed and implemented a multi-tenant backend architecture with tenant isolation;
• Built a dynamic pricing engine supporting discounts, payment rules, and volume logic;
• Implemented a ZIP-code-based freight calculation system;
• Integrated WhatsApp Cloud API for automated conversational quote workflows;
• Designed approval flows for unknown SKUs and price validation;
• Built background job processing using Redis workers for scalable quote generation;
• Structured domain models for retail operations and pricing management;
• Led full product architecture from database schema to API design.

An AI-first product platform focused on building large-scale consumer applications powered by machine learning and large language models. The system supports millions of users across education and productivity products, operating with high concurrency, real-time AI inference, and production-scale data processing. Alongside user-facing applications, internal infrastructure was developed to unify marketing data across multiple channels, enabling automated decision-making and AI-driven optimization workflows.

• Contributed to backend architecture serving millions of users across AI-powered products;
• Refactored the MongoDB data layer to async, improving throughput under high concurrency;
• Designed queue-based background processing using Redis and workers;
• Worked on marketing data unification platform (RootKit), consolidating multi-channel data ingestion and normalization;
• Built scalable APIs for internal analytics and automation workflows;
• Implemented cost-optimization strategies for LLM-based features.

A multi-tenant booking platform connecting service providers and venues, featuring end-to-end proposal lifecycle management. The system includes marketplace payment functionality powered by connected accounts, supporting platform fees, delayed payouts, and secure transaction handling between participants.

• Architected and implemented Stripe Connect marketplace integration;
• Designed split payments, platform fee logic, and delayed payout mechanisms;
• Built a secure multi-tenant backend with RBAC and isolation per account;
• Designed proposal-to-payment lifecycle with escrow-like logic;
• Optimized database queries and improved transaction consistency;
• Led backend architecture decisions and payment infrastructure design.

A professional social networking platform designed for skilled trades professionals, allowing users to create profiles, share content, and connect with peers through a mobile-first interface. The system included social feed functionality, support for user-generated content, and built-in monetization features such as payments and advertising infrastructure.

• Led backend development for payment and monetization features;
• Designed and implemented in-app payment flows and subscription logic;
• Integrated payment providers and ensured secure transaction handling;
• Built advertising infrastructure and monetization workflows;
• Designed APIs supporting sponsored content and ad placement logic;
• Worked on user profile systems and core social interaction features;
• Contributed to scalable backend architecture supporting user-generated content.