Vitaliy Sazonov

A platform to launch sites, Telegram bots and mini-apps from pluggable modules. Project → Site → Modules tenancy with strict per-site data isolation; modules (shop/orders, booking, CMS, reviews, pricing, loyalty) and adapters for external services (payments, Telegram, storage, notifications) selected per site by config; per-site RBAC; dual auth (JWT for admins, Telegram HMAC for mini-app clients); three Next.js frontends on one API.

A single multi-tenant API (payments / refunds / payouts / disputes) over provider adapters; monotonic state machine with advisory locks; outbox of signed webhooks; merchant-scoped isolation; OpenAPI as the source of truth.

Two products on one backend: realtime translation (STT → MT → TTS via Pipecat + LiveKit) and AI meeting notes (action items, decisions, RAG brief over pgvector); payments behind adapters.

Self-hosted conversion service (images ↔ PDF): async job pipeline (202 + Celery), magic-byte validation, API keys, S3, signed webhooks, Node and Python SDKs.

Multi-tenant optimization gateway (any → WebP/AVIF) over an external service, with its own tenancy, quotas, S3 storage and token encryption (Fernet).

SEO / Tech SEO / Performance / AI-ready auditor: URL → crawl → 726 canon checks → weighted scoring → PDF report; checks as data (checks.yaml registry), not code.

Infrastructure and secrets manager (a simpler take on HashiCorp Vault): encrypted secrets with versioning and rollback, SSH-tunnel command generation, full audit log.

SaaS that turns an AI interview into full project docs (ADRs, sprints, task specs, CLAUDE.md, machine context) ready for AI assistants and CI/CD.

Backend & AI Engineer

• ▸Designing and running my own production products end-to-end (see Own Products): appKit, PayKit, lingvo, fileforge, croply. Full-time on own products since 2023; alongside employment before that.

Backend / Web Developer

• ▸Complex CRM and business systems, queues, DevOps, deployment.
• ▸Interactive catalog: resumable large-file uploads (TUS protocol), PDF processing, Google Cloud Push/Pull queues; MySQL → PostgreSQL data migration.
• ▸Commodity exchange: implemented broker ↔ dealer deals, background jobs (Celery / Celery-beat), CSV import/export via Django admin, compliance changes.
• ▸Logistics tracking: containerization (Docker), DRF REST API, third-party tracking API integration, webhooks, Swagger docs, deployment.
• ▸CRM for agribusiness (frontend): client dashboard, registration/auth and admin-impersonation login, Docker build, CI/CD pipeline.

Python · Django · DRF · Celery · PostgreSQL · Docker · React · Vue · Quasar · TypeScript

Backend Developer

• ▸Automated multi-channel campaign systems for business: SMS, MMS, Email, Web Push, PWA — deliverability and scaling.

Python · Django

Bitrix / PHP Developer

• ▸Bitrix/PHP web development: modules and components, markup integration, events and agents, access control, site security and performance.

Developer (Swift)

• ▸EXTTAP — a messenger and business tool for assigning and tracking tasks across contacts.

Junior Bitrix / PHP

• ▸First commercial role on Bitrix Framework: modules and components, markup, mail templates, events, agents, access control and site search.