braunmann

Building backend integration services in TypeScript for supplier and partner data sync, mapping, and reliability. Designing and maintaining REST APIs consumed by internal teams and partner systems. Working in a Kubernetes environment; supporting production debugging and reliability improvements. Contributing to internal admin tooling in React (feature work + API/UI integration).

Owned replatforming of legacy PHP monolith to modular multitenant Node.js services on AWS (EC2 + Serverless). Rebuilt event-driven bidding engine in Node.js for 5k+ concurrent users with WebSocket scaling - real-time event propagation and state management directly analogous to chain event listener architectures. Delivered an in-house EventSourced PIM using AWS Serverless and OpenSearch, exposed via REST API. Introduced flexible inter-service communication using REST APIs, gRPC, and SNS/SQS. Implemented DDD practices and domain-oriented design patterns at service and system level.

Built and maintained backend microservices in TypeScript for smart-meter billing workflows. Implemented AWS Lambda functions connected with SQS queues for reliable async data processing. Coded and optimized billing and pricing algorithms for smart-meter (IoT) data, processing millions of readings daily. Delivered under high SLA and reliability requirements.

Maintained @golem-sdk/golem-js - the official TypeScript SDK for a decentralized compute marketplace where payments are settled on-chain via GLM (ERC-20, Ethereum + Polygon). Led a full rebuild of the SDK public API - no official documentation available, so the new architecture was grounded in reverse-engineering event schemas and internal contracts directly from the yagna daemon's Rust source code. Defined TypeScript contracts for the low-level SDK layer based on undocumented yagna internals; built high-level abstractions on top, shielding application developers from raw WebSocket event handling. Owned the full release pipeline: Rollup bundling, NPM package publishing, semantic-release versioning, and GitHub Actions CI/CD ensuring safe weekly releases. Built an interactive React playground visualizing live event flow across all three system layers (Golem Network nodes → yagna daemon → SDK) - enabling developers to understand low- and high-level event propagation without reading source code. Supported partner teams integrating the SDK; gathered community feedback from Discord/GitHub and translated it directly into API design decisions.

Owned replatforming of legacy PHP monolith to modular multitenant Node.js services on AWS (EC2 + Serverless). Rebuilt event-driven bidding engine in Node.js for 5k+ concurrent users with WebSocket scaling - real-time event propagation and state management directly analogous to chain event listener architectures. Delivered an in-house EventSourced PIM using AWS Serverless and OpenSearch, exposed via REST API. Introduced flexible inter-service communication using REST APIs, gRPC, and SNS/SQS. Implemented DDD practices and domain-oriented design patterns at service and system level.

Returned to lead modernization of the core platform - decomposed legacy monolith into domain-oriented services (PIM, Stock/ETA, OMS, Back Office). Rebuilt inventory, stock/ETA, and order management systems with clear bounded contexts and shared contracts. Bridged business and technology - translated commercial use cases into actionable technical designs.

Built a React + Electron EPOS desktop app integrated with Venditan's e-commerce platform. Implemented offline-first caching, automatic sync, and multi-store configuration. Integrated Verifone ECM payment terminals (device handshake, card vaulting, receipt printing).

Built a proprietary e-commerce platform and custom Order Management System for the furniture industry. Led integrations with ~100 suppliers (pricing, stock, shipping/logistics APIs), maintaining ~30k products. Designed scalable solutions for high-traffic operations supporting ~5k concurrent users at peak.