AI Engineering
Notes on MCP, agents, context engineering, RAG, vector search and integrating AI into real software systems.
Oleg Patsay
I design systems that scale with the business
AI, Architecture & Complex Systems
I design and evolve software systems that scale with products, teams and business complexity.
12+ years in software engineering · FinTech · GameDev · HealthTech · EdTech · MarTech
Integrations
- MCP
- HTTP API
Services
- Go
- Rust
- PHP
Data
- PostgreSQL
- Qdrant
Infrastructure
- Docker
- Linux
Tools chosen to fit the problem.
12+ years in software engineering
- FinTech
- GameDev
- HealthTech
- EdTech
- MarTech
- Architecture
- Engineering Leadership
- Backend Systems
- AI Engineering
- Legacy Modernization
Writing
Software Engineering
Architecture, complex systems, legacy modernization, delivery and engineering practices that keep software changeable.
Engineering Leadership
Technical strategy, ownership, engineering organizations and leading teams through AI-enabled change.
Featured writing
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Agent-ready codebase: how to prepare your code for AI agents
How Git, ACDD, DDD, SOLID, tests, documentation, backlog, and linters help AI agents understand a codebase and safely change legacy systems.
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AI Code Review: What to Check in AI-Generated Code
AI has made code generation cheaper, but not understanding. Review shifts from syntax to intent, scope, architecture, business invariants, failure paths, and whether the code should exist at all.
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Who Is Responsible for AI-Generated Code?
AI changed who produces the text, but not who decides to keep it in the system. Ownership remains with the human who understands the change and accepts the merge.
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How to Introduce AI into a Legacy System Without Rewriting It
Keep the legacy application as the system of record and add AI beside it as a new layer: adapters, read-only scenarios, shadow mode, and gradual expansion of capabilities.
Selected Work
MARTECH
Webmaster MCP
Connecting Webmaster to my agent, with explicit boundaries for reads, quotas, cancellation and uncertain writes.
A self-hosted Go MCP server for my SEO Agent: indexing, diagnostics and search reports, a read-only mode and bounded access to the Yandex API.
MARTECH
Google Search Console MCP
Connecting Google search analytics to SEO Agent while retaining dates, incomplete-data boundaries and access errors.
A Go MCP server for reading Google Search Console: four tools, explicit analytics contracts, service-account access and a reproducible demo.
How I Approach Engineering
Architecture
Complex systems should remain understandable enough for teams to change them safely.
Responsibility
AI speeds up edits. What lands in the system is the engineer's call.
Change
A system needs to change regularly without losing control of it.
About
I'm Oleg Patsay, a software engineer and engineering leader with more than a decade of experience building backend systems, evolving complex software and leading engineering teams.