Guilherme Soares Sousa Silva

Backend engineering for DETRAN-PR’s production digital services platform supporting citizen services and mission-critical internal operations, with complex business rules, integrations, security, traceability, and reliability requirements.
• Designed and implemented backend services and REST APIs in Go and Node.js for critical production flows, reducing average execution time by approximately 35%

Digital services platform in production for a state traffic authority, supporting citizen service and mission-critical internal operations, with complex business rules, multiple integrations, and high requirements for security, traceability, and reliability.

• Designed and implemented product backend services and REST APIs in Go and Node.js for critical business flows in production, reducing aver

Product SaaS for the real estate market with more than 96,000 registered users, covering CRM, property listings, leads, integrations, and automations that support the daily operations of real estate agencies.

• Built and evolved REST APIs and product backend services in Node.js and TypeScript, delivering features on a platform with more than 96,000 registered users.
• Restructured lead-processing

Digital transformation of the commercial operation of an electronic components distributor, previously fragmented across spreadsheets, messaging apps, and manual catalog and order controls, consolidated into a single product system.

• Built the product backend in Go and Node.js, connecting catalog, orders, and administrative operations through structured REST APIs.
• Replaced manual order-control

Financial product integrated into a retail operation with more than 5,000 stores, a critical system where data inconsistencies, integration failures, or incorrect authorization directly affect financial and operational transactions.

• Built backend services and REST APIs in Node.js for financial transactions and integrations used by a network of more than 5,000 stores.
• Implemented business vali

Internal systems for a legal operation that relied on spreadsheets, documents, emails, and manual controls to execute administrative and case-related workflows.

• Built internal applications and backend services in Go, replacing workflows previously distributed across spreadsheets, emails, and manual document controls.
• Designed REST APIs and business rules to centralize administrative informati

Software house environment with projects across e-commerce, real estate, CRM, compliance, and administrative systems, requiring frequent adaptation to different domains, legacy systems, and business rules.

• Built backend services, REST APIs, and business rules primarily in Node.js for e-commerce, CRM, real estate, and administrative products.
• Integrated external systems and internal modules, r

Independent software development work for small businesses, covering websites, e-commerce, integrations, and custom web solutions for specific commercial needs.

• Built web applications and backend features using Node.js and PHP, translating business requirements into features used in production.
• Developed and customized Magento e-commerce stores, implementing checkout, catalog, integration, an