Alex – AWS, .NET, CI/CD

Shared caching infrastructure for a cross-border e-commerce platform that lets brands and retailers sell to shoppers in more than 200 markets, handling local pricing, duties, payments and international shipping. It serves about 20 GB of business data to 150+ application instances, both the legacy monolith and newer services, so the platform can scale without overloading its primary database during peak shopping seasons.

• Designed and built a hybrid caching system that removed database-intensive startup and refresh operations from the primary database while preserving order-processing throughput through peak shopping seasons;
• Personally implemented about 75% of the Hybrid Cache SDK, delivered as reusable NuGet packages for legacy .NET Framework 4.8 applications and modern .NET microservices, with Redis Enterprise, Kafka-based cache synchronization and a local caching layer with TTL, LRU eviction and indexed lookups;
• Built a dedicated snapshot microservice that serializes and compresses cached data with Protocol Buffers and publishes it to Amazon S3 together with Kafka stream positions;
• Designed a snapshot-based startup strategy: instances preload data from S3 and replay subsequent Kafka events, catching up in a couple of minutes and avoiding the Redis and network bottlenecks found in large-scale performance testing;
• Worked with the engineering team to integrate the SDK into the legacy monolith, validating compatibility across 180+ cached entity types and coordinating testing, deployment and operational readiness;
• Ran performance analysis and optimization in dedicated test environments with Datadog tracing

A bot-detection and prevention service for a cross-border e-commerce platform that lets brands and retailers sell to shoppers in more than 200 markets. It protects the platform and its merchants from automated order placement and malicious traffic by filtering requests at the platform's traffic entry point, before they reach checkout.

• Led the architectural redesign of the bot-detection service so it could handle platform-wide traffic and protect all merchants, not just a subset;
• Designed a high-performance approximate sliding-window rate-limiting algorithm using current- and previous-minute counters in Couchbase, keeping database operations to a minimum while staying accurate enough to detect automated traffic;
• Architected the integration between a .NET microservice and Cloudflare JavaScript middleware to identify requests and apply configurable rate limits at the traffic entry point;
• Replaced one-size-fits-all restrictions with merchant-specific policies tailored to each merchant's traffic patterns and security needs;
• Made merchant onboarding and rate-limit configuration self-service for Operations, removing recurring engineering involvement;
• Presented the architecture to the CTO, VP of Engineering and VP of Payments, and led the team that implemented it

The central sign-in and access system for a cross-border e-commerce platform used by brands and retailers selling in more than 200 markets. It authenticates merchants' users and their connected systems, and lets enterprise merchants sign in through their own corporate identity providers, replacing legacy API keys and username/password logins while keeping older merchant integrations working.

• Led the Foundation team's delivery and ongoing ownership of the platform's authentication infrastructure, working with the architecture team to roll out a centralized identity solution on Auth0, Tyk API Gateway and .NET;
• Implemented modern human-to-machine and machine-to-machine authentication flows while keeping legacy GUID-based API authentication and existing merchant integrations working;
• Co-developed an internal .NET authentication microservice that integrates with Auth0, caches issued JWTs in Redis and creates application sessions, so identity-provider tokens never leave the internal Kubernetes infrastructure;
• Built custom JavaScript middleware for Tyk API Gateway to route external authentication requests to the internal service and manage session-cookie access;
• Implemented enterprise SSO with SAML, supporting merchant-specific identity-provider setups;
• Designed internal management APIs for user provisioning and Auth0/SAML configuration, letting Operations administer merchant authentication without engineering help

A platform that retail, hospitality, restaurant and other businesses use to run in-store music, digital signage and audio messaging across their locations. It delivers content to media players installed on site and lets each business control what plays where, for a provider serving more than 500,000 customer locations in over 140 countries.

• Led the gradual move from a legacy .NET Framework monolith to 30+ microservices on AWS while the platform grew from about 10,000 to 150,000 connected Android players, without disrupting existing customers;
• Introduced RabbitMQ and MassTransit for event-driven communication and applied Domain-Driven Design to split media-handling logic into services with their own PostgreSQL databases and events, reducing dependencies across the platform;
• Moved persistent WebSocket connections out of the IIS monolith into horizontally scalable SignalR services, using RabbitMQ for command delivery and as the backplane across instances;
• Moved media files from Windows application servers to Amazon S3 and CloudFront, taking significant traffic off IIS and letting content delivery scale independently of the backend;
• Designed and built a dedicated identity service with JWT-based authentication and authorization for human, machine and mobile clients;
• Introduced Docker, automated builds and deployments with GitHub Actions, and later moved the platform to Kubernetes on AWS EKS;
• Kept making architectural decisions and writing production code throughout, and was the most active code contributor in an engineering organization of 20+ developers

The engineering organization behind the in-store music and digital signage platform of a global experiential-media provider serving more than 500,000 customer locations in over 140 countries. The platform grew into the company's flagship product as the business expanded internationally.

• Grew from Team Lead to Senior Engineering Manager while the business grew about tenfold, managing multiple teams with 20+ developers, including remote outsourced engineers;
• Introduced trunk-based development, Continuous Delivery and automated integration testing, making releases simpler, more frequent and less dependent on manual steps;
• Introduced DevOps practices, hired and managed the first DevOps engineer, and automated infrastructure and deployments together with him;
• Presented DORA metrics and Continuous Delivery principles to senior management to improve how delivery was measured, and introduced regular penetration testing with the teams fixing the findings;
• Represented engineering in the technical due diligence for the company's acquisition by Vector Capital, explaining the architecture and practices to auditors, and evaluated the technology and teams of companies Mood Media acquired;
• Worked with Product and UX on the platform's direction and drove the frontend move from AngularJS to React and later Next.js;
• Mentored developers, including a junior engineer who became one of the strongest developers on the team within two years

The company aimed to make software more intelligent through machine learning.

• Co-founded the company to build more intelligent software through machine learning.
• Explored natural-language processing, speech processing, and computer vision.
• Worked with decision trees, support vector machines, neural networks, and regression models.
• Worked toward creating an SDK that other developers could use in their own applications.
• Combined machine learning with computer vision in several experimental projects.

A configurable document-processing and data-entry platform for large-scale digitization projects in the public and private sectors. Organizations define their own document types, forms, validation rules and workflows instead of commissioning a separate application for each contract, and large operator teams process millions of documents through it.

• Took over a reusable-platform initiative that had failed twice before and designed and built XDE, which became the company's standard platform for all subsequent document-processing contracts;
• Designed the client-server architecture with C#, WPF, WCF, Entity Framework Code First and SQL Server, including the database model, dependency injection, modular design and MVVM;
• Built a WPF administration tool for configuring document types, fields, layouts and validation rules, plus server-side C# code generation that compiled project-specific models into .NET assemblies used by operator clients with strongly typed data binding;
• Worked closely with operations management to shape the platform around real workflows of hundreds of operators, improving it based on their feedback;
• Recruited and led a team of 4–5 mostly junior developers while remaining the primary architect and developer;
• Delivered XDE for major public-sector projects, including electoral-list indexing and public-records digitization for ANCPI, Romania's national cadastre agency, reusing one platform across projects with different document structures