Work

Qualifications.

AgentsHarnesses, tool calling, orchestration, multi‑agent, LangGraph, MCP servers
EvalsGolden datasets, LLM-as-judge, regression evals, CI release gates
ObservabilityTracing, cost and latency monitoring
SafetyGuardrails, hallucination checks, prompt injection tests
RAGEmbeddings, retrieval, vector databases
Context engineeringAgent skills (SKILL.md), system prompts, structured outputs
MultimodalOCR, speech‑to‑text (Whisper), text‑to‑speech, VLM, image/video generation
ModelsClaude, GPT, Gemini, Grok, DeepSeek, Kimi, open-source (Qwen, Llama, uncensored Gemma)

- AgentsHarnesses, tool calling, orchestration, multi‑agent, LangGraph, MCP servers
- EvalsGolden datasets, LLM-as-judge, regression evals, CI release gates
- ObservabilityTracing, cost and latency monitoring
- SafetyGuardrails, hallucination checks, prompt injection tests
- RAGEmbeddings, retrieval, vector databases
- Context engineeringAgent skills (SKILL.md), system prompts, structured outputs
- MultimodalOCR, speech‑to‑text (Whisper), text‑to‑speech, VLM, image/video generation
- ModelsClaude, GPT, Gemini, Grok, DeepSeek, Kimi, open-source (Qwen, Llama, uncensored Gemma)
- WebPlaywright, Cypress, Selenium, WebdriverIO
- MobileAppium, Android, iOS, emulators, simulators, farms (LambdaTest, BrowserStack)
- APIPostman, Swagger, OpenAPI, REST, GraphQL, WebSockets
- PerformanceAPI (k6, JMeter, Gatling), WebSockets (k6, Artillery)
- SecurityNetwork leakage tests, SAST (DefectDojo), Claude Security
- BlockchainFoundry, Tenderly, Synpress
- TrafficDevTools, mitmproxy, Fiddler, Charles, Wireshark
- ApproachesPage Object, risk-based, exploratory, data-driven, BDD (Cucumber), shift-left, cross-platform, regression, accessibility
- Test designECP, BVA, DTT, EG, STT, PWT
- DocumentationTest plans, test cases, checklists, bug reports, test reports, acceptance criteria, RTM, dashboards
- Test managementJira, Xray, Zephyr, TestRail, Notion, Confluence
- ProcessSDLC, STLC, Agile, Scrum, Kanban
- LeadershipHiring, mentoring, estimation
- BackendTypeScript, Node.js, Python
- APIs & realtimeREST, GraphQL, webhooks, WebSockets, SSE
- DatabasesSQL: PostgreSQL, MySQL, NoSQL: Firestore, MongoDB, Redis
- QueuesKafka, Pub/Sub, RabbitMQ
- FrontendReact, Next.js
- CloudGoogle Cloud (certified), AWS, Hetzner, Akamai
- IaC & GitOpsTerraform, Argo CD
- ContainersDocker, Kubernetes, Helm
- CI/CDGitHub Actions, GitLab CI, Jenkins
- NetworkingVPN, TCP/IP, DNS, routing, firewalls, traffic analysis
- SystemsLinux, Windows, macOS
- ObservabilityLogs, metrics, load, agent monitoring
- Blockchain infraValidator and full nodes, testnets
- Product designWireframes, user flows, high-fidelity UI
- UITypography, grids, visual hierarchy
- ResearchReferences, surveys, user interviews
- PrototypesFigma, code, AI-assisted
- Design systemsTokens, components, guidelines
- AccessibilityWCAG, contrast, focus states, semantic markup
- BrandIdentity, illustration style, personal brand systems
- Hello.English · English
- Здравей.Български · Bulgarian
- Привет.Русский · Russian
- Привіт.Українська · Ukrainian

# Serge Vinterman (vinterman) Builder and quality seeker: product engineer with a QA Lead and SDET background. Sofia, Bulgaria. - LinkedIn: linkedin.com/in/serge-vinterman - Email: vintermanserhii@gmail.com ## Current project **Limitless**: Product Engineer, 2025 — now, Prediction markets · full-time - Ships features end to end: idea, design, code, tests, release, support - Fixes bugs across frontend and backend - Daily AI work: custom harnesses and pipelines, knowledge base, skills, debugging and monitoring, release gates - Manual and automated tests: new features, custom trading core (CLOB, AMM, neg-risk, ladder markets, RFQ, parlays) - Iterates test automation (frontend, backend, integration, load) for several production releases a day ## Previous projects **Skipr**: QA & AQA Lead, 2024 — 2025, Patented security protocol · full-time - Built QA from zero: process, docs, dashboards, automation, QA team hiring - E2E automation: web (Playwright), mobile (Appium), API (TS + Axios), load (k6 + Artillery), GitHub Actions CI/CD - Real iOS and Android device farms (LambdaTest), flaky-test hunting, scheduled regression with alerting - Security for gov and enterprise clients: VPN leak tests (DNS, IP, traffic), no-data-collection checks, SAST; quality demos and reports for investors - Wrote features and fixed bugs in product code (Node, Flutter) **Turbo Stars**: Senior QA & AQA Engineer, 2022 — 2024, Betting · full-time - Organised QA on a microservices platform with dense math logic - UI framework (Playwright) and API framework (TypeScript, Axios, Chai), GitLab CI/CD - API testing, manual (Postman, Swagger) and automated (own framework); load tests on critical scenarios (k6) - Jira productivity dashboards and charts for a big team - Onboarded and mentored 2 QA engineers **Web33**: AQA Engineer, 2020 — 2022, DeFi · full-time - Built test automation from zero for 15+ client projects - Web (Selenium) and mobile (Appium, Android emulators) suites for client DeFi apps - Load and stress tests against bot traffic and multi-accounting: Gatling (API), Artillery (WebSockets) - Self-hosted test pipeline: Jenkins → DockerHub → Helm → Argo CD → Kubernetes - Monitoring and support of delivered client projects: Prometheus, Grafana, alerts **Crypto projects**: Builder, node operator, tester, 2019 — 2021, Freelance - Testnet bug hunting and reports for early-stage projects - Ran early validator and full nodes on own and rented hardware - Built and ran own servers: overclocking, uptime, repairs - Wrote autotests for projects, whale-wallet checkers and trading bots: spot, futures, cross-exchange, copy-trading ## Qualifications ### AI - Agents: Harnesses, tool calling, orchestration, multi-agent, LangGraph, MCP servers - Evals: Golden datasets, LLM-as-judge, regression evals, CI release gates - Observability: Tracing, cost and latency monitoring - Safety: Guardrails, hallucination checks, prompt injection tests - RAG: Embeddings, retrieval, vector databases - Context engineering: Agent skills (SKILL.md), system prompts, structured outputs - Multimodal: OCR, speech-to-text (Whisper), text-to-speech, VLM, image/video generation - Models: Claude, GPT, Gemini, Grok, DeepSeek, Kimi, open-source (Qwen, Llama, uncensored Gemma) ### Quality - Web: Playwright, Cypress, Selenium, WebdriverIO - Mobile: Appium, Android, iOS, emulators, simulators, farms (LambdaTest, BrowserStack) - API: Postman, Swagger, OpenAPI, REST, GraphQL, WebSockets - Performance: API (k6, JMeter, Gatling), WebSockets (k6, Artillery) - Security: Network leakage tests, SAST (DefectDojo), Claude Security - Blockchain: Foundry, Tenderly, Synpress - Traffic: DevTools, mitmproxy, Fiddler, Charles, Wireshark - Approaches: Page Object, risk-based, exploratory, data-driven, BDD (Cucumber), shift-left, cross-platform, regression, accessibility - Test design: ECP, BVA, DTT, EG, STT, PWT - Documentation: Test plans, test cases, checklists, bug reports, test reports, acceptance criteria, RTM, dashboards - Test management: Jira, Xray, Zephyr, TestRail, Notion, Confluence - Process: SDLC, STLC, Agile, Scrum, Kanban - Leadership: Hiring, mentoring, estimation ### Development - Backend: TypeScript, Node.js, Python - APIs & realtime: REST, GraphQL, webhooks, WebSockets, SSE - Databases: SQL: PostgreSQL, MySQL, NoSQL: Firestore, MongoDB, Redis - Queues: Kafka, Pub/Sub, RabbitMQ - Frontend: React, Next.js ### Cloud - Cloud: Google Cloud (certified), AWS, Hetzner, Akamai - IaC & GitOps: Terraform, Argo CD - Containers: Docker, Kubernetes, Helm - CI/CD: GitHub Actions, GitLab CI, Jenkins - Networking: VPN, TCP/IP, DNS, routing, firewalls, traffic analysis - Systems: Linux, Windows, macOS - Observability: Logs, metrics, load, agent monitoring - Blockchain infra: Validator and full nodes, testnets ### Design - Product design: Wireframes, user flows, high-fidelity UI - UI: Typography, grids, visual hierarchy - Research: References, surveys, user interviews - Prototypes: Figma, code, AI-assisted - Design systems: Tokens, components, guidelines - Accessibility: WCAG, contrast, focus states, semantic markup - Brand: Identity, illustration style, personal brand systems ## Certificates - Associate Cloud Engineer (Google): https://www.credly.com/badges/d63ed157-3b60-4a11-9b10-917aea45c1f7/public_url - Fundamentals of OS (Udemy): https://udemy-certificate.s3.amazonaws.com/image/UC-2e314c58-edf5-4dce-b1e5-4be4f848d5a5.jpg - Master Redis, from beginner to advanced (Udemy): https://udemy-certificate.s3.amazonaws.com/image/UC-fb8eaf65-5308-495c-b214-49eab2a1a508.jpg - Fundamentals of Database Engineering (Udemy): https://www.udemy.com/certificate/UC-bf7376b1-83c7-41ea-8b7b-c0d61ad310a8/ - Realtime Backend System Design with WebSockets (Udemy): https://udemy-certificate.s3.amazonaws.com/image/UC-3f2660a3-f970-4b5e-a69b-adcf4d653cdd.jpg - Fundamentals of Backend Engineering (Udemy): https://udemy-certificate.s3.amazonaws.com/image/UC-5c43d135-7445-4700-8551-a9da0a48a27d.jpg - Next.js & React, the complete guide (Udemy): https://ude.my/UC-eff030f3-124c-4bf3-90b2-82cc3ced6b6c - Python Application (Stepik): https://stepik.org/cert/1514701?lang=en - Python Core (Sololearn): https://www.sololearn.com/Certificate/CT-ANNKBBSU/png - SQL (Sololearn): https://sololearn.com/certificates/course/en/25949305/1073/landscape/png ## Languages - English, Bulgarian, Russian, Ukrainian ## After hours - Teleword: Telegram bot for learning English · https://github.com/vinter-man/teleword - cad-helper: Plain text → CAD drawing · https://github.com/vinter-man/cad-helper