Vetted Visual Studio Professionals

Osvaldo Calles

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Senior Software Engineer specializing in developer tools, cloud automation, and generative AI

Redmond, WA13y exp

“Built and deployed a production chatbot on osvaldocalles.com and iterated through real-world LLM engineering issues: model quota/cost tradeoffs (migrating to Nova Pro), RAG accuracy via semantic chunking, AWS IAM/guardrail/security pitfalls, and Lambda/API Gateway streaming constraints (prefers JS for streaming layer). Experienced with agent orchestration using Strands SDK (AWS-focused) and LangGraph (Vercel/container deployments), plus evaluation pipelines using LLM-as-evaluator, dashboards, and staged model rollouts.”

“IAM/platform engineer with experience at DocuSign and Siemens who ships production-grade systems end-to-end: built a secure AWS serverless internal employee-profile API (OAuth2/Cognito/WAF) that cut data retrieval from weeks to near-instant and sustained ~2,800 RPS at ~75 ms. Also delivered production AI workflows, including a GPT-4o + Playwright crypto-scam detection agent and an NLP ticket-routing system improved to ~86.7% accuracy with strong monitoring and incident mitigation practices.”

“Front-end engineer who significantly owned the Microsoft Teams personal copilot web experience for enterprise customers, including real-time streaming chat powered by WebSockets and bot infrastructure. Stands out for combining browser UI architecture, accessibility/localization work across 30 languages, and strong production telemetry/incident ownership for reliability at scale.”

“Unity/C# gameplay engineer who has shipped both core systems and live multiplayer features, including a modular real-time inventory system that cut crashes by 80% and improved retention. Built an LLM-driven NPC dialogue pipeline with caching, fallbacks, batching, and fine-tuned models, iterating via player feedback and analytics. Shipped a Photon Fusion multiplayer metaverse with rigorous network simulation and CI stress testing, and has VR optimization experience (Meta Quest constraints) on Horizon Worlds.”

KARTHIKBABU VADLOORI

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Mid-level Full-Stack Developer specializing in Spring Boot, React, and cloud microservices

San Francisco, CA5y exp

“Backend engineer with experience at Meta and Accenture building regulated-data systems (healthcare/financial) using Python/Flask and Postgres. Has scaled high-throughput services to millions of daily requests, delivering measurable latency wins (~40% API latency reduction; ~35% faster DB-backed endpoints), and has productionized ML inference services using Docker/Kubernetes and AWS (ECS/SageMaker).”

“Unity/C# gameplay engineer who has shipped across console/PC/VR and mobile, including Ace Combat 7 (VR) and mobile titles. Built monetization-impacting gameplay systems (power-ups) and a full server-authoritative multiplayer architecture, and uses LLM-driven editor tooling and multi-agent workflows to rapidly prototype features while adding automated testing, benchmarking, dashboards, and CI/CD.”

Joseph Leybovich

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Senior Unity Engineer specializing in XR and game development

Culver City, CA13y exp

“Unity/C# gameplay engineer with hands-on experience shipping end-to-end game systems, including a story mode pipeline on Marvel Mighty Heroes that supported designers directly and improved player retention. Also brings experimental AI/LLM and VR experience from Meta hackathons plus Photon multiplayer and cross-platform VR/mobile prototyping expertise.”