About
AI engineer in Vilnius
I'm Simas Razinskas. I build AI systems for customer support, operations and products, and I run them in production. I work in person in Vilnius or remotely.
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Since 2025 most of my work has been for a consumer subscription business: its support agent, the data and payment-dispute automation around it, the chat service behind its in-app assistant, and the internal dashboard its teams work in. The case studies cover each system in detail.
Most of my code is written by AI coding agents. Tests, evaluations and review decide what merges, the same way they would for a person.
contributions in the last year
Live from GitHub + GitLab2,100+
AI-agent branches merged into production
12+
years writing code
Experience
2026
Own products and a company
Founded a company around a voice-first language tutor, and built the products listed below. All of it runs on servers I operate, alongside sites I host for other people.
2025 → 2026
AI support and operations for a subscription business
A support agent that drafts and acts on tickets, a mirror of the ticket history joined to order data, chargeback evidence, marketing email, ad operations and an internal dashboard. Most merges came from AI-agent branches.
2025 → 2026
In-app AI assistant and marketing AI
For the same business: the chat service behind its in-app AI assistant, with analytics over its conversations, plus AI moderation of comments on ads and tooling for testing ad creatives.
2024 → 2025
Media AI and localization
Localization of video, audio and images: transcription, translation, voice cloning and GPU inference on serverless hardware. Dubbed videos stay frame-accurate, with the original background audio intact.
2024 → 2025
AI and field tools for a road operator
An internal AI assistant that answers staff questions from the operator's own documents behind their directory sign-in, a road-inspection app, a road-asset register on a map, and a browser extension that turns inspection findings into finished reports.
2024
Learning platforms
For a professional-training company: a new learning platform with courses, assignments, consultations and a calendar, its admin panel, and upkeep of the seminar-registration site that came before it.
since 2014
Writing code
More than a decade of building software: websites, CRMs and commerce platforms first, then products across many languages and frameworks.
Products of my own
What I build and run outside client work.
- Live
An issue tracker for people and AI agents
People and coding agents work from the same board. Agents sign in as their person, finish work from the command line and hand it to a review queue. An optional AI layer reads each issue and never changes anything on its own.
- Pre-launch
A voice-first language tutor
A speaking game for adult beginners, run as its own registered company, with the site and sign-up live. In each lesson a real-time voice character talks with the learner, while ordinary code decides when a scene is complete.
- Prototype
Production software for furniture workshops
One parametric model of each job drives measuring, kitchen layouts, drawings, cut lists, sheet nesting, CNC programs, pricing and invoices. Looking for its first pilot workshops.
Stack
- AI
- Claude and OpenAI APIs · Vercel AI SDK · Evals and LLM judges · Structured outputs and tool calling · Retrieval (RAG) · Real-time voice · Claude Code, Codex and MCP
- Languages
- TypeScript · Go · Python · C# · Swift · SQL
- Backend and data
- PostgreSQL · BigQuery · Redis · Effect · Hono · tRPC
- Frontend and apps
- Next.js · React · Tailwind CSS · SwiftUI · React Native
- Integrations
- Zendesk · Stripe · PayPal · n8n
- Infrastructure
- Docker · Kubernetes on AWS · Traefik · Prometheus and Grafana · OpenTelemetry · GitLab CI
Code activity
Most of my work lives in private repositories, so this shows contribution counts rather than code: GitHub live, GitLab from a one-time snapshot.
