Богдан

BOHDAN HAVRYLIUK
Full Stack AI Engineer • AI Automation • Backend • LLM Systems
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PROFILE
Full Stack AI Engineer with 5+ years of software engineering experience and 4+ years of hands-on AI
development, model evaluation, and AI-enabled product delivery. Experienced in building end-to-end systems
across async Python, .NET, LLM integrations, backend APIs, databases, cloud deployment, and voice AI. Built
and support production automation used by real recruiters and candidates. Currently founder and sole engineer of
Kalorad, a self-hosted AI platform running on a model I trained myself.

KEY SKILLS
Languages: Python, C#, C++, C, JavaScript, PHP, Lua, SQL, HTML/CSS
AI / LLM: Claude API, LLM tool use, prompt engineering, AI response evaluation, RLHF / AI training pipelines,
NLP, computer vision, voice AI, PyTorch, LLM pretraining & fine-tuning, self-hosted inference, RAG
Backend & Infrastructure: FastAPI, asyncio, SQLAlchemy 2, Alembic, Pydantic, .NET / ASP.NET, Node.js,
PostgreSQL, SQLite, Redis, Docker, Docker Compose, Caddy, VPS
Integrations: Vapi, Deepgram, ElevenLabs, SIP, Telegram MTProto / Telethon, KeyCRM REST, webhooks, REST
APIs, S3-compatible storage
Languages Spoken: English (fluent), Ukrainian (native), Russian (native)

EXPERIENCE
Founder & AI Engineer — Kalorad | May 2026 – Present (Own product)
• Built a sovereign AI SaaS end to end as the sole engineer: own 1.3B decoder-only model
(GQA/SwiGLU/RoPE/RMSNorm, 4k context) with a daily self-training loop — automatic scoring, checkpoint
promotion, rollback on regression.
• Developed the platform on ASP.NET Core 9: streaming chat, RAG with cite-or-abstain, decaying long-term
memory, a permissioned tool router, 20 vertical agent packs, and an OpenAI-compatible public API.
• Implemented monetisation with Stripe (subscriptions, one-off SKUs, usage metering) plus a gamified loyalty
layer whose unit economics are modelled and reproducible in Python.
• Shipped growth infrastructure: Telegram bot integration, push chains, a referral loop with anti-abuse trust
levels, and an admin analytics dashboard.
• Ran a security audit and fixed two real vulnerabilities — CSRF across 33 of 37 POST endpoints and a stored
XSS — then added a site-wide CSP, rate limiting and account lockout; verified against the running
application.
• Covered the system with executable smoke suites (94/94 monetisation, 22/22 router, 108/108 agent packs)
run on every build.
AI Training Contractor — Scale AI | Jan 2026 – Jul 2026 (Part-time freelance, Remote)
• Evaluated AI-generated code and technical responses for correctness, helpfulness, safety, and best
practices.
• Performed side-by-side comparisons across coding, algorithm analysis, and problem-solving tasks.
• Assessed time/space complexity, programming principles, and security considerations in AI outputs.
• Solved advanced Python coding exercises to validate AI capabilities and identify failure modes.
• Flagged harmful or policy-violating responses to support model quality and safety improvements.
AI Trainer — Meta | Jan 2025 – Feb 2026 (Part-time contract, Hybrid)
• Contributed to training and fine-tuning large-scale AI models through structured data generation and
feedback.
• Reviewed and rated model outputs across technical and general domains to improve response quality.
• Applied software development and AI expertise to assess accuracy, usefulness, and clarity of model content.
Team Lead & Software Developer — Client under NDA | Sep 2023 – Sep 2025 (2 Years)
• Led project teams to deliver complex software and AI solutions on time and within scope.
• Coordinated task distribution and streamlined collaboration workflows across team members.
• Architected and built backend and full-stack applications using C#, .NET, Python, and SQL.
• Enforced code-quality standards and drove continuous performance optimisation.
Freelance Full Stack AI Engineer — Self-employed | 2021 – Present (ongoing private-client work,
alongside the roles above)
• Designed and delivered full-stack, backend, and AI automation solutions for private clients, from requirements
and UX through development, delivery, and support.
• Built production applications using Python, C#, .NET / ASP.NET, JavaScript / Node.js, SQL and PostgreSQL,
REST APIs, Docker, and responsive UI/UX workflows.
• Built scalable business logic, integrated relational databases, and maintained high code standards across
diverse technology stacks.
• Delivered several non-disclosable professional projects under NDA.
PRODUCTION PROJECTS
AI Voice Recruiter "EVA" — End-to-End Hiring Automation (Python, FastAPI, Claude API, Vapi,
PostgreSQL)
• Sole developer of a production system for Kozyr Trans that autonomously calls candidates in Ukrainian, runs
structured screening, and routes qualified candidates to recruiters; processed 300+ live calls.
• Integrated KeyCRM end to end: candidate cards are created and moved through the funnel automatically with
transcript, call recording, AI summary, and structured screening fields.
• Built a Telegram MTProto follow-up agent for unreachable candidates, merging voice and chat dialogs into
the same CRM card with deduplication.
• Implemented async services with FastAPI, SQLAlchemy 2, Alembic, PostgreSQL, Claude API, Vapi,
Deepgram, ElevenLabs, SIP, webhooks, Docker Compose, Caddy, and APScheduler.
• Added resilience features including SIP diagnostics, voicemail detection, concurrency/per-person call caps,
and self-healing reconciliation of unfinalized calls and missed events.

SELECTED FULL-STACK PROJECTS
Personal Blueprint — AI Numerology Report SaaS (Python, FastAPI, Claude, Jinja2, SMTP)
• Built a full-stack solo SaaS flow from landing page and checkout through deterministic date-of-birth
calculations, Claude-generated personalized reports, branded HTML/PDF rendering, and email delivery.
• Implemented signature-verified payment webhooks, a 208-block knowledge base, prompt guardrails and
linting, an optional PDF pipeline, and 34 offline pytest tests.
Nexus — SaaS Licensing & Secure Script Delivery Platform (ASP.NET Core, PostgreSQL, Redis,
Avalonia)
• Built a personal SaaS project for hardware-bound license activation and AES-256 encrypted script delivery.
• Implemented PostgreSQL/Supabase persistence, Redis caching and rate limiting, Paddle subscription
webhooks, and a cross-platform Avalonia desktop client.
dZENcode Comments SPA (Django, DRF, Channels, Celery, RabbitMQ, PostgreSQL, Redis, Elasticsearch,
Vue 3)
• Built a Dockerized cascading-comments SPA with unlimited reply depth, CAPTCHA, attachments, JWT auth,
real-time WebSocket updates, live preview, validation, and XSS/SQLi protections.
• Designed scale-ready backend features: GraphQL, async search indexing, idempotency middleware, rate
limiting, S3/CDN attachment support, Prometheus metrics, read-replica routing, partitioning template, and
Locust load tests.

UNIVERSITY PROJECTS
AI Conversational Chatbot (Python, NLP, REST API)
• Built a context-aware chatbot with NLP preprocessing, intent recognition, entity extraction, and a REST API
layer for external applications.
Rice Variety Classification via Transfer Learning (MATLAB, AlexNet / GoogLeNet)
• Applied transfer learning, data augmentation, stratified splits, SGDM fine-tuning, and accuracy/confusion-
matrix evaluation.

EDUCATION
BSc (Hons) Artificial Intelligence — De Montfort University, Leicester | 2023 – Present
• Core modules: Machine Learning, Neural Networks, Computer Vision, Intelligent Systems, Data Structures &
Algorithms, Software Engineering.
• Current Average: First Class Honours (71.7%).