Максим

Max Yastremskyi
Senior Backend Engineer · Tech Lead - PHP / Laravel · Node / NestJS · AI-Assisted Development & Applied AI
[open contact info](look above in the "contact info" section) · [open contact info](look above in the "contact info" section) · [open contact info](look above in the "contact info" section) · github.com/YasMax91 · yastremskyi.com · Ukraine · UTC+3 ·
Open to remote & relocation

SUMMARY

Senior Backend Engineer and Tech Lead with 6+ years building production Laravel platforms for CRM, e-commerce, manufacturing and premium-
services businesses, many of them from an empty repository. I own the domains that must not be approximately right - order lifecycles, multi-
station production workflows, payments, clearing and accounting - on the latest stack (PHP 8.4, Laravel 12), and integrate payment, messaging,
calendar and logistics providers with sandbox-verified reliability. I authored Groundwork, an open-source (MIT) multi-agent platform for spec-
driven development adopted across 12 codebases, ship applied-AI features in production and have mentored 5 engineers.

SELECTED ACHIEVEMENTS

Authored and open-sourced (MIT) Groundwork - an AI spec-driven development platform (Claude Code plugin): 5 specialized review agents,
17 automated gates, 54 releases since June 2026 with 549 hook tests in CI - adopted across 12 production codebases (800+ procedure runs,
300+ specs, 90 auto-generated frontend hand-offs); ~1/3 of tasks are stopped before code as mis-scoped.
Shipped applied AI in production: voice intake (Whisper STT → schema-constrained, temperature-0 LLM extraction → structured actions)
behind real-time WebSocket delivery, an intent gateway that validates model output instead of auto-executing it, and OCR/computer-vision
document parsing - with provider fallback, prompt-injection defenses and response-regression tests.
Built payment & financial subsystems where mistakes are irreversible - PCI tokenization, idempotent clearing, multi-currency money,
accounting/tax export and signed-webhook reconciliation.
Built a reusable multi-market headless e-commerce platform (Laravel 12): one codebase cloned per market, with storefront API, back-office
admin, retail/wholesale pricing engine, pluggable payments and delivery, and staged 1C (ERP) catalogue sync.
Delivered multiple order-lifecycle & production-workflow platforms (multi-station scan/barcode tracking, QC, weighted auto-assignment)
with server-side RBAC, Hebrew/RTL document rendering and multi-channel messaging.

EXPERIENCE

RaDevs · Product studio - Laravel back-ends & AI tooling Apr 2024 – Present
Senior Backend Engineer · Tech Lead
Architecture, delivery and technical leadership across multiple production Laravel platforms (e-commerce, CRM, manufacturing, premium services)
plus the studio's AI-assisted development platform.
– Authored Groundwork - an open-source (MIT) AI spec-driven development platform (Claude Code plugin): risk-based task classification (L0–
L4), 5 review agents (impact map, blind-spot map, grounded external-API research, adversarial verification, conformance), 17 automated gates
(format, static analysis, tests, OpenAPI contract, defect scan, migration locks, full suite before push) and a companion-plugin ecosystem.
Adopted across 12 production codebases; ~1/3 of tasks stopped before code as mis-scoped.
– Built delivery management into Groundwork: estimates quoted from a ledger of measured agent time (median and sample size), client-
facing scope documents generated in English with a Russian mirror, and live verification against the running app before a task can close.
– Built and maintain a reusable, multi-market headless e-commerce platform (Laravel 12): a storefront JSON API (catalogue, category trees,
characteristics, cart, wishlist, search, checkout, orders, account) plus a back-office admin panel - cloned per market with config-driven currency,
locale and timezone.
– Implemented the commerce core: a retail/wholesale pricing & discount engine (per-channel product/category rules, discount cascade,
promo pricing), driver-abstracted payments (LiqPay online + cash-on-delivery; Stripe) and delivery (Nova Poshta), buyer auth (JWT +
Google/Facebook OAuth + email OTP), queued transactional email, SEO (JSON-LD, sitemap/robots) and an admin home-page builder.
– Built a staged 1C (ERP) catalogue sync - queued job chains staging per-product changes via typed DTOs for admin review/apply - with
Excel/PDF import-export and image sync.
– Built a production AI gateway microservice that translates CRM conversation turns into validated model intents (tool-calling) without auto-
executing them - OpenAI Whisper speech-to-text tuned with domain vocabulary (incl. Hebrew), pinned models, per-call cost accounting and
shared-secret auth.
– Shipped LLM features in production - a voice dictation assistant creating/updating client records from speech (verbatim Hebrew
transcription, tool-loop, PII-safe) and voice task intake (Whisper → schema-constrained / temperature-0 extraction) behind WebSocket delivery,
with provider-mocked CI, audit and prompt-injection defenses; plus OCR / computer-vision (Tesseract, OpenCV) and typo-tolerant search &
ranking (Meilisearch/Algolia).
– Automated voice debt-collection for a community-management platform - synthesized Hebrew speech over telephony with live-operator
handoff - with recurring standing-order billing (Grow) and Masav direct-debit collection.
– Architected order-lifecycle & production-workflow systems: multi-station barcode/scan movement tracking, quality-control and supervisor
approvals, staff attendance and weighted auto-assignment - with centralized state-transition guards and server-side RBAC.
– Engineered payment & financial subsystems: card tokenization (PCI - tokens only), hierarchical payment requests, idempotency-keyed
clearing, multi-currency decimal-string money (bcmath), clearing-gateway integrations and accounting/tax export, with signed-webhook
reconciliation and all-or-nothing document issuance.
– Delivered multi-channel messaging with driver fallback chains (Twilio → WhAPI → WhatsApp Cloud API), delivery-status webhooks and
language-aware templates (Hebrew/English/Spanish), plus Hebrew RTL/bidi document rendering (mPDF/dompdf routing) for correct invoices
and tickets.
– Built an async media-processing microservice (FFmpeg + Imagick, S3/MinIO, Redis-queued jobs, webhooks, OAuth2 client-credentials),
integrated calendar (Google Calendar two-way sync), scheduling (Boulevard GraphQL) and real-time flight monitoring, and added an
integration health-probe registry (credential masking) to catch silent failures before users.
– Designed microservice architectures with versioned REST APIs documented via OpenAPI (l5-swagger), whitelisted query filtering, event/job-
driven side effects, and realtime channels over WebSockets (Pusher protocol / Soketi / Reverb).

– Set the team's engineering standards and Definition of Done - test-first (TDD), static analysis (PHPStan/Larastan), Pint, OpenAPI contracts
and auto-generated frontend hand-offs - and mentored 5 engineers through code review, the review agents and architecture decisions.
Stack: PHP 8.4 (8.2–8.4), Laravel 12, MySQL 8, Redis/Horizon, JWT · Sanctum · Passport (M2M), Socialite (Google/Facebook), Soketi/Pusher/Reverb, spatie
(permission/translatable/sluggable), LiqPay, Nova Poshta, 1C (ERP), Resend, FFmpeg, Imagick/Intervention, AWS S3 · MinIO, Twilio & WhatsApp Cloud API,
Google Calendar, Boulevard (GraphQL), OpenAI (Whisper, GPT-4o-mini) & Anthropic Claude, Meilisearch/Algolia, Docker, GitHub Actions, l5-swagger/OpenAPI,
PHPStan/Larastan, Pint.

TerraForce Software · E-commerce, admin & mobile backends Aug 2022 – Mar 2024
Full-Stack PHP Engineer
Back-end work across e-commerce, admin/CRM platforms and mobile app APIs, with third-party payments, search and messaging integrations.
– Built and maintained e-commerce backends: Stripe/Cashier subscriptions and payments, WayForPay + Nova Poshta for local checkout and
delivery, shopping cart, wishlist, multi-language storefronts, SEO (sitemaps/redirects) and response/query caching.
– Developed Laravel Nova admin panels with custom tools, cards, fields and dashboards - including a leads-management CRM (intake, lead
actions, reporting) with rich-text editing and invoicing/PDF generation.
– Integrated OpenAI (GPT) for content generation - an early LLM integration - alongside Google APIs and web-scraping/parsing pipelines.
– Built API-first mobile app backends (JWT, FCM push, Google 2FA, PDF/Word/Excel generation on S3) and search-driven features
(Elasticsearch, Meilisearch/Scout), GeoIP targeting, Twilio SMS / Telegram notifications and real-time WebSockets.
– Integrated marketplaces, domain registrars and third-party ecosystems (Amazon SP-API, Namecheap/GoDaddy, Google APIs, Facebook,
Strava) behind a unified layer with retry/backoff and idempotency.
Stack: Laravel 8–10, PHP 8.1, Laravel Nova, MySQL, Redis, Stripe/Cashier, WayForPay, Nova Poshta, Amazon SP-API, Namecheap/GoDaddy, Google APIs,
Elasticsearch/Meilisearch, Twilio, Firebase FCM, AWS S3, OpenAI.

Imrev · Digital Agency Jun 2020 – Aug 2022
PHP Engineer
– Built e-commerce and corporate web platforms end to end (custom Laravel modules, admin panels, storefronts) across concurrent client
projects.
– Integrated payment, shipping and analytics providers, replacing manual client workflows with automated order flows.
– Optimized page, catalog and search performance (query tuning, indexing, caching) and owned post-production incident handling.
Stack: PHP, Laravel, MySQL, JavaScript, Redis, REST integrations.

YUKS++ · Desktop software Jan 2020 – Jun 2020
Junior Engineer (C++ / .NET)
– Maintained and extended legacy C++/.NET modules, contributed to a VB.NET → WinForms migration and resolved pre-release defects during
QA/hardening cycles.
Stack: C++, C#/.NET, VB.NET, WinForms.

S I D E P R O J E C T S & C O N S U LT I N G

– Telegram forum-moderation bot (Python, aiogram 3, Clean Architecture) - captcha onboarding, pattern-based anti-spam, user trust scoring,
tiered plans, EN/RU/UK i18n; 80 pytest tests, with QA and fix agents that verify the bot against its own suite.
– Telegram scheduling bot (Python, aiogram 3, APScheduler, Docker) - built end to end by a coding agent from a single written spec.
– Technical pre-sales (concept) - designed an LLM order-intake architecture for a B2B distributor: schema-constrained extraction from email,
Excel and messenger orders, deterministic validation, Telegram human-in-the-loop approval, and unposted drafts written to 1C/BAS through an
ERP-agnostic adapter.

TECHNICAL SKILLS

AI-Assisted Development - authored & open-sourced (MIT) Groundwork, a Claude Code plugin for spec-driven development: multi-agent review
(impact / blind-spot / grounded research / adversarial verification / conformance), risk-based task classification, 17 automated gates, live
verification, measured estimates, auto-generated API contracts, companion-plugin ecosystem; custom subagents and skills (UI/UX audit, QA and
fix agents, PHPDoc generation); MCP; local speech-to-text (whisper.cpp) for task intake.
AI / LLM Engineering - OpenAI (Whisper, GPT-4o-mini, JSON-schema / structured outputs, temperature-0 extraction) & Anthropic Claude;
production LLM pipelines (STT → structured extraction → action), tool-calling intent gateway, human-in-the-loop approval, prompt-injection
defense, provider fallback, cost accounting, response-regression tests; TTS telephony (Hebrew), Tesseract OCR, OpenCV, Meilisearch / Algolia.
Backend - PHP 8.2–8.4 (Laravel 12, Octane; latest 13 / PHP 8.5), Messaging & Integrations - Twilio (WhatsApp Business API, SMS),
NestJS/Node, REST + OpenAPI/Swagger, WebSockets, queues WhatsApp Cloud API, WhAPI, Telegram Bot API,
(Redis/Horizon), JWT · Sanctum · Passport (M2M), microservices, Resend/Mailgun/Postmark; Google Calendar/Gmail, Boulevard
DDD, Spatie ecosystem. (GraphQL); Nova Poshta, Ukrposhta, CountryStateCity.
Payments & Accounting - Stripe (Cashier), PayPal, Green Cloud & DevOps - Docker (Nginx/PHP-FPM/Supervisor, Traefik, Let's
Invoice/Morning (tokenization + clearing), Meshulam, Grow (Bit), Encrypt), AWS (S3/CloudFront/EC2/SQS), GitHub Actions, Horizon,
Cardcom, LiqPay, WayForPay, 2Checkout, MIGS, Masav/Nedarim Sentry, Cloudflare Tunnel, health-probe monitoring.
Plus; SUMIT, Rivhit; PCI tokenization, idempotency, webhook Frontend & Leadership - Vue 2/3, React, TypeScript/JS · authored
reconciliation, standing orders / recurring billing, direct debit, multi- team AI-development methodology & standards, multi-agent code
currency (bcmath). review, mentored 5 engineers, stakeholder communication,
Python - aiogram 3, APScheduler, pytest, Flet, SQLite, Clean prioritization, architecture & ADRs.
Architecture (side projects). Quality - test-first (TDD), PHPUnit/Pest, PHPStan/Larastan/Psalm,
Data & Storage - MySQL 8 (profiling, indexing), PostgreSQL, Redis, Pint, feature flags, canary releases, spec-driven development,
AWS S3 / MinIO, Meilisearch / Algolia. OpenAPI contracts.

L A N G U A G E S & AVA I L A B I L I T Y

English - B2 (Upper-Intermediate) · Ukrainian - Native · Russian - Fluent | Remote worldwide · Relocation-ready · Available at 2 weeks' notice