Problems where architecture shows up as latency, cost, and trust.

The team needed more than services. They needed shared patterns for commands, queries, events, auditability, and cloud integration so 22 developers could move without each squad inventing its own architecture.

I helped design and implement a domain-driven CQRS/event-sourcing framework with clear bounded contexts, replayable event history, cloud abstractions, and documentation the team could use day to day.

• 40% faster development: shared patterns reduced repeated architecture work across squads.
• Cloud flexibility: the framework supported Azure, AWS, and GCP deployment paths.
• Audit-ready history: event sourcing made state changes traceable and replayable.

At this scale, good architecture reduces coordination cost. The win was not just a cleaner diagram. It was a system teams could extend without losing consistency.

The product depended on LLM calls, but provider latency, outages, and cost swings made the experience hard to control. The team needed a system, not scattered API calls.

The routing architecture scores providers, enforces budget controls, emits telemetry, and handles fallback behavior. Those mechanisms make model calls easier to inspect; they do not prove performance outcomes.

• Routing and caching: separate provider execution from suitable response reuse.
• Budget controls: make spending constraints and usage visible.
• Evidence status: no verified latency, cost-saving or uptime results are published for this architecture.

LLM cost and latency are product problems, not just infrastructure details. Provider telemetry can inform product and engineering decisions; the resulting impact needs measurement.

The prototype could generate answers, but the team needed source citations, freshness controls, and a way to know whether retrieval quality was actually improving.

I designed a RAG pipeline around pgvector, metadata filters, re-ranking, offline evaluation, and dashboards for answer quality, latency, and cost.

• 85% answer accuracy, up from 40% (+45 percentage points) on a 500-question evaluation set: better chunking, ranking, and evaluation.
• Citation-ready answers: users could inspect where answers came from.
• Operational visibility: dashboards made quality and performance easier to manage.

RAG without evaluation turns into prompt tuning by instinct. The important shift was giving the team a feedback loop they could trust.

The agency needed a payment gateway that could handle sensitive transactions, integrate with existing systems, and satisfy compliance review without last-minute cleanup.

I built a REST WebAPI with secure data handling, authentication and authorization patterns, transaction audit trails, integration documentation, and operational logging.

• 100% audit pass rate: no critical findings reported.
• Millions of transactions processed: high-volume payment path handled securely.
• Cleaner handoff: documentation supported future maintenance and review.

In regulated systems, the boring details are the system: logs, encryption, permissions, failure behavior, and documentation all have to be designed on purpose.

Shoppers needed to narrow a large catalog quickly. Full page reloads, slow filters, and weak caching made product discovery feel heavier than it needed to be.

I implemented AJAX filtering, query optimization, caching, responsive filter behavior, and measurement around conversion and result latency.

• 15% conversion uplift: better discovery led to more completed purchases.
• 60% faster result times: optimized queries and caching reduced wait time.
• Better mobile behavior: filtering stayed usable across screen sizes.

Search is one of the places where backend work becomes revenue. Fast, trustworthy product discovery changes how shoppers move through the catalog.