David Petric

Direct Debit SaaS Platform

Working on a React-based feature for SaaS enabling customers to upload and process various banking file formats including BACS Standard 18 and SmartDebit CSV files.

The application parsed transaction data and integrated with multiple banking gateways to facilitate seamless payment processing. Performance Optimization at Scale: Resolved critical performance issues in a 2.5 TB database environment, optimizing queries for a table containing 300M+ rows to improve client custom report generation.

Enhanced payment file processing capabilities, reducing execution time for 1.2M record files from 4.5 hours to approximately 20-40 minutes.

Database Migration Leadership: Created Architecture Decision Records documenting the impact analysis for migrating from latin1_swedish to utf8mb4 encoding.

GenAI/LLM Integration & Team Leadership: Led team training sessions on best practices for leveraging GenAI/LLM tools in software development.

Utilized AI-assisted development to accelerate delivery ofUnicode/Welsh language support across DD registration forms, pages, emails, and templates.

Code Quality & Mentorship: Delivered clean, maintainable C# backend services while mentoring team members on performance optimization and scalable code architecture. Introduced comprehensive unit testing practices and established patterns for writing testable code across the development team.

Conducted thorough code reviews identifying performance anti-patterns such as inefficient database queries, in memory filtering, and excessive memory allocations.

Developed Model Context Protocol (MCP) servers the to index API endpoints.

Championed DORA for quick and high-quality delivery, advocating for QA test automation, integration testing, and E2E testing.

Tech: React, TypeScript, C# / .NET, MySQL, AWS (S3), Docker, REST APIs, Git, Unit Testing, Software Design, GenAI/LLM tooling

Project: Property Management System (Greenfield)

Client: Knight Frank

Worked on a Event Driven Greenfield solution using C#, Angular 16, Azure Cloud(Azure Functions, Service Bus, CosmosDB), CQRS,

DevOps & Quality: Established comprehensive CI/CD pipelines in Azure DevOps with Docker containerization; enforced code quality via automated static analysis and high unit-test coverage.

Integrations: Engineered complex third-party integrations (Fixflo, MRI Software) to automate payment processing and synchronize data for Tenants and Landlords.

Security: Implemented robust security protocols using MSAL for secure API communication and Managed Identity for cloud resource access.

Hold knowledge sharing sessions for development team on serverless patterns and Azure Service Bus, while collaborating with stakeholders to refine business requirements.

Project: Tenancy Progression (Brownfield)

Client: Knight Frank

Digital Transformation: Modernized legacy workflows by replacing manual paperwork with automated digital solutions, integrating DocuSign for e-signatures and Homeppl for reference checks.

Document Automation: Developed a system for dynamic legal document generation (Tenancy Agreements) using Aspose, significantly reducing administrative overhead.

Search & Data: Implemented advanced search capabilities and dashboards using Elasticsearch.

Project: Transport Management System & Mobile Migration

Client: 365 Response (RLDatix)

Legacy Modernization: Spearheaded the migration of Client and Driver mobile applications from PhoneGap to Xamarin Forms, establishing a shared core architecture.

Backend Optimization: Refactored legacy .NET backend code for the web application and implemented DevExpress controls for document management.

Quality Assurance: Introduced and enforced Unit Testing principles to replace manual testing reliance, improving system stability.

Part picker warehouse management system project for a client in Germany:

Wrote a functionality to assign a picker light that interacted with an Arduino and assigned a Warehouse employee a light so that he would be able to pick.

The client had an API in place which we integrated to get information about orders that employers

would need to pick from the warehouse.

Responsible for creating and maintaining Azure DevOps pipelines with the ability to build, test(unit tests, UI tests), release Xamarin Forms, NuGet packages.

Integrate SonarQube code analysis hosted in Docker on an on-premises server in all Azure DevOps, pipelines for better cost.

Key Technologies: C# / .NET, ASP.NET, SQL Server, Entity Framework, REST APIs, Unit Testing, Integration Testing, Azure, Azure DevOps, Sonar, Docker, Git, Xamarin Forms