/01Solve the real problem
Every line of code is downstream of a clear problem statement. I'd rather spend a day understanding the system than a week patching it.
Fullstack & AI systems engineer.
I ship the parts you don't see.
6+ years building scalable backends, RAG-powered products and the infra that keeps them honest. Currently a Senior Software Engineer at Zocks, building AI for financial advisors.
$ curl -X GET /v1/me
-H "Accept: application/json"
{
"name": "Erik Csiki",
"role": "Senior / Lead Engineer",
"based_in": "Budapest, HU",
"experience_years": 6,
"focus": [".NET", "AI", "RAG"],
"currently": "Senior SWE @ Zocks",
"available": true
}
$
01 — Philosophy
Product-minded engineering,end-to-end ownership.
I'm a senior engineer who works the full stack of decisions — from the architecture call at the top, to the migration script at 2am, to the conversation that unblocks a teammate the next morning. Reliable, technical, and quietly opinionated about how good systems get built.
/02Ship boring backends
"Boring" is a compliment. Predictable, observable, well-tested services beat clever ones — especially when AI is involved.
/03Cost is a feature
For LLM systems especially, inference cost is the product economics. Prompt caching, retrieval design, and model choice are first-class engineering concerns.
/04Mentor outward
The best engineers I know explain freely and document what they learn. I try to leave the team — and the codebase — stronger than I found it.
02 — Stack
The tools, picked carefully.
A working stack — what I reach for week to week, grouped how I actually think about it.
.NET 9/10 Web APIASP.NET MVCC#JavaRESTGraphQLWebSocketReactTypeScriptViteTanStack Router/QueryTailwind CSSshadcn/uiWCAG / a11yAzure AI FoundryRAG architecturepgvectorHybrid searchEmbeddingsPrompt cachingLLM cost optimizationAzure APIMAzure App ServiceDockerKubernetesFeature flagsPostgreSQLMicrosoft SQL ServerNoSQLpgvector store
03 — Track record
Six years, five chapters.
Production engineering at two AI companies, enterprise .NET delivery, and half a decade of university teaching alongside it.
ZK
Jul 2026 — Present
Backend engineering at the privacy-first AI assistant for financial advisors. Building the systems that turn client conversations into structured data — and sync it across CRMs, planning tools and forms at enterprise scale.
PB
Mar 2022 — Jul 2026
Lead engineer on AI search and conversational commerce. Designed and shipped a production RAG pipeline, owned end-to-end delivery across backend, infra and admin tooling, and acted as technical PM for enterprise rollouts.
DS
Jul 2020 — Feb 2022
Built enterprise-grade .NET back-end systems and integrations for regulated clients. Strengthened delivery practices, owned services from spec to production, and contributed to architectural decisions on multi-team programs.
EL
Sep 2019 — Jan 2025
Taught programming and software engineering to undergraduates over five years. Mentored students through projects, code reviews and thesis work — many now active engineers across Hungarian tech.
ED
Graduated 2020
BSc in Software Engineering. Foundation in algorithms, distributed systems, and software architecture that still shapes day-to-day technical decisions.
04 — Selected work
Things I built, and what they did.
Six shipped pieces of work — from a full RAG platform to platform integrations and accessibility wins.
AI Platform
AI Chat API with full RAG pipeline
Designed and shipped a production retrieval-augmented chat API powering on-site shopping assistants for enterprise e-commerce tenants.
−50%
GPT cost
20+
Tenants
p95 < 1.2s
Latency
Platform
Controlled rollouts for an agentic platform
Feature-flag-driven release system enabling progressive delivery of agent capabilities across tenants and cohorts.
Per-tenant
Tenants
Instant
Rollback
Product
Admin Portal, redesigned from scratch
Modern internal portal built on React + TanStack + shadcn/ui, replacing a legacy back-office that customers and ops teams lived in daily.
40+
Pages
Cut by half
Ops time
Integration
Shopify integration
Native Shopify integration for AI search and assistant features, end-to-end.
Live
Storefronts
Integration
BigCommerce integration
Sister integration for BigCommerce — bringing the AI stack to a second e-commerce platform.
BigCommerce
Platform
Accessibility
WCAG search widget
Hardened the on-site search widget for keyboard, screen-reader and contrast accessibility.
AA
WCAG
05 — Leadership & teaching
Leading quietly, teaching openly.
Five years at Eötvös Loránd University in parallel with shipping software. Mentorship runs through both.
Mentoring engineers
From juniors to mid-level engineers — pairing, code review and growth conversations. Mentored students into engineers, and engineers into senior contributors.
Technical project management
Acted as technical PM for enterprise rollouts: scoping, planning, stakeholder alignment, and keeping engineering on the critical path.
Teaching at university
Five years teaching programming and software engineering at ELTE. Curriculum, lectures, labs, thesis supervision — for hundreds of students.