Pavlo

PAVLO KOSTETSKYI
Senior Software Engineer / Backend Architect — Go · Rust
Ukraine (open to remote) · [open contact info](look above in the "contact info" section) · [open contact info](look above in the "contact info" section) · github.com/kostecmw · artifacted.app

SUMMARY
Backend engineer and architect with 20+ years in software development, including 8+ years building high-load distributed
systems. Deep expertise in Go; production experience with Rust (including Solana dApps). Led the decomposition of a monolithic
PHP platform into 20+ Go microservices with event-driven architecture and event sourcing, cutting hot-path latency by up to
two orders of magnitude. Founder of Artifact Engine — an AI task-decomposition engine that cuts LLM token spend by up to 50×
versus open-ended agentic sessions. Former team lead: hiring, code review, Agile/SCRUM adoption, technical documentation.

CORE SKILLS
• Languages: Go (primary), Rust, PHP, TypeScript/JavaScript, Node.js; working knowledge of C/C++, Java, Python, Elixir
• Architecture: microservices, Event-Driven Architecture, Event Sourcing, gRPC/Protobuf, WebSockets, REST, DSL design
• Messaging & data: NATS JetStream, Kafka, RabbitMQ, Redis, PostgreSQL, MySQL, MongoDB, DynamoDB, InfluxDB,
OpenSearch
• Infrastructure & observability: Docker, GitLab CI/CD, Prometheus, Grafana
• Web3: Solana SDK, dApp development (Rust)
• Integrations: HubSpot, Salesforce, Creatio, Zoom SDK, OAuth 2.0

EXPERIENCE
Founder & Lead Engineer · Artifact Engine (artifacted.app) 2025 – Present
AI-assisted software engineering platform, written entirely in Go.
Stack: Go, AI/LLMs, CLI
• Designed and built an artifact-driven engineering platform from the ground up: CLI tooling, artifact validation pipeline, and
execution engine that decompose complex software systems into structured artifacts
• Enables simple, low-cost LLMs to develop complex applications — cutting token spend by up to 50× versus an open-ended
agentic session while reducing hallucinations and context-window load
• Specification pipeline produces a complete, validated project spec in ~11K tokens on a flash-class model; implementation
runs at ~14K tokens and ~2 minutes wall-clock per module on a low-cost coding model

Senior Software Engineer · DeepStake Jun 2025 – Present
Blockchain infrastructure and staking applications for the Solana ecosystem.
Stack: Rust, Go, PHP, React, Node.js, Solana SDK, PostgreSQL
• Maintained customer-specific patches to the Solana validator core (Rust), adapting and re-integrating them across upstream
Solana releases
• Built a Solana staking widget embedded on the main product page (deepstake.info)
• Developed a stake-claiming application (Node.js, PostgreSQL, React)
• Built a Solana validator delegation application and several small dApps (Rust, Solana SDK)
• Implemented a lightweight VPN service written entirely in Go

Backend Architect · PitchAvatar Jan 2024 – May 2025
AI-powered online presentation platform (SaaS).
Stack: Go, NATS JetStream, OpenSearch, Redis, Gin, InfluxDB, Prometheus, Grafana, PostgreSQL, WebSockets, gRPC
• Decomposed a monolithic PHP/Laravel platform into 20+ Go microservices and migrated legacy PHP code to Go
• Introduced Event-Driven Architecture and Event Sourcing: cut average request latency by ~200 ms — up to two orders of
magnitude on hot paths (hundreds of ms → single-digit ms) — and fully eliminated long-running (500 ms+) requests
• Replaced Laravel queues with goroutines and NATS JetStream, eliminating 100% of scenario-hang incidents caused by queue
latency
• Built a microservice subsystem tracking presentation-session state and triggering scenarios defined in a custom DSL; moved
scenario execution fully to the backend, reducing a minimal scenario operation from ~600 ms to hundreds of nanoseconds

Team Lead · PitchAvatar Sept 2022 – Jan 2024
Led the engineering team behind the presentation platform's core product.
Stack: PHP, Go
• Managed a team of 4 engineers (2 backend, 2 frontend): code review, task decomposition, technical documentation,
deadline and quality control, technical interviews
 • Introduced Agile/SCRUM as the core development methodology and adopted git-flow
• Implemented a billing system supporting multiple payment scenarios
• Delivered Salesforce and Creatio integrations

Senior Backend Engineer (PHP/Go) · PitchAvatar Aug 2021 – Sept 2022
Designed and implemented backend services for the online presentation platform.
Stack: PHP, Laravel, Go, Node.js, Zoom SDK, HubSpot SDK/API, OAuth 2.0
• Built a service converting video (YouTube, MP4) into presentation slides (PPTX and an internal optimized format), using
perceptual hashing (Hamming distance) to detect unique slide frames
• Implemented a bridge service between the presentation platform and live Zoom sessions, synchronizing presentation state
and media streams (Go, Zoom SDK, Node.js, PulseAudio)
• Developed a production-grade HubSpot App integration with OAuth 2.0 authentication and CRM synchronization
(PHP/Laravel, Go)

Senior Backend Engineer (PHP) · TopBSR 2019 – Jul 2021
Amazon marketplace sales analytics platform.
Stack: PHP, Yii2, JavaScript, PhantomJS, Docker, GitLab CI
• Developed an application for analyzing sales performance metrics on the Amazon platform
• Containerized the application (Docker, docker-compose) and set up the CI/CD pipeline

PHP/JS Developer (Junior → Middle) · TopBSR 2017 – 2019
Stack: PHP, Yii2, JavaScript, PhantomJS
• Developed backend and frontend functionality for the Amazon analytics platform; wrote unit tests, delivered production
code from specifications

Earlier career 2001 – 2017
• Independent e-commerce developer (2014–2017): built solutions on PrestaShop, WordPress, Contao, OpenCart
• CMS e-commerce developer (2011–2014): 1C-Bitrix stores integrated with 1C Enterprise systems
• 1C Developer / System Administrator (2001–2011): business applications on the 1C Enterprise platform

EDUCATION
Zaporizhzhia Engineering Academy — Enterprise Economics 2004
Zaporizhzhia National Technical University — B.Sc., Computer Studies 2001

LANGUAGES
Ukrainian (native) · Russian (native) · English (B2)