/about

Session history

I build and lead production software. Fifteen years plus in the JavaScript ecosystem — most of it spent making systems other engineers can change without fear.

These days the work spans the stack: Node.js services and architecture on the back, Vue and React consoles on the front, and AI-native workflows threaded through both. I optimise for delivery, maintainability, and matching complexity to the actual problem.

I'm equally comfortable owning an architecture decision, untangling a difficult module, or pairing with an agent to move faster. The constant is judgment — knowing which of those a situation calls for.

experience

kostadin@portfolio:~ % grep "experience" profile.md

2021 — now

Principal / Staff Engineer

Independent · fintech, AI platforms, retail

Architecture, delivery leadership, and AI-native platform work for teams scaling production systems. Event-sourced ledgers, evaluation infrastructure, edge rendering.

2016 — 2021

Tech Lead · Frontend & Full-stack

Product companies (operator tooling, SaaS)

Led front-end architecture for operator consoles and dashboards on Vue and React; owned design-systems, performance budgets, and team mentoring.

2011 — 2016

Full-stack Engineer

Agencies & early-stage startups

Shipped across the JavaScript stack as it matured — Node.js services, SPA front-ends, build tooling. Where the 10,000 hours came from.

values

kostadin@portfolio:~ % inspect engineering-values.json

engineering-values.jsonread-only

{

"maintainability": "code is read 10× more than written",

"delivery": "shipped & observed beats perfect & pending",

"refactoring": "make change cheap, continuously",

"pragmatism": "match complexity to the actual problem",

"product-minded": "the system exists to serve users",

"ai-native": "agents draft, engineers arbitrate"

}

stack

kostadin@portfolio:~ % ls -R ./stack

languages: TypeScriptJavaScriptSQLPythonGo
backend / runtime: Node.jsgRPCKafkaTemporalPostgreSQLRedis
frontend: Vue 3ReactNext.jsAstroVitePinia
ai-native: LLM pipelinesevalsagent workflowsRAGprompt infra
practice: architecturerefactoringobservabilityCI/CDmentoring

›download --cv cv.pdf ›open ./portfolio ›connect --with Kostadin

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