Andrii Kalmus - Abysim

Senior Software Developer · AI Agent Engineer · Tier 3 Support Team Lead · Technical Product Owner

Remote (European & North American hours) · Open to full-time or part-time · Bulgaria

andrii.kalmus@abysim.com · github.com/Abysim · linkedin.com/in/abysim · medium.com/@abysim

Summary

Senior software engineer, 14 years shipping production software, 9 of them at iGMS, a Canadian B2B SaaS, on host-automation across Airbnb, Vrbo, and Booking.com. Now working as an AI agent engineer: at iGMS, built the internal AI orchestration the engineering team uses daily — a multi-agent code-review skill, a multi-stage ticket-investigation skill, and a QA test-plan generator. Side project: bigcats.org.ua, a wildlife-news site live since 2022, multi-agent pipeline automating it since early 2025.

Skills

AI & agents: Multi-agent LLM pipelines, function calling, tool use, MCP, Claude Code, GitHub Copilot, LLM-as-judge and multi-model eval, RAG, prompt engineering, Claude / GPT / Gemini / Qwen
Languages & frameworks: PHP, Laravel, JavaScript, TypeScript, React, SQL
Backend & data: REST and third-party API integration, MySQL, Redis, Elasticsearch, ZeroMQ, WebSockets, async webhooks
Infrastructure & observability: AWS, Docker, Datadog, ClickHouse, log-driven production debugging
Engineering practices: SOLID, DRY, YAGNI, root-cause analysis, evolving long-lived codebases in place

Experience

iGMS · Contract · Canada (Remote) · February 2017 – Present

Three concurrent roles at the same company. Joined iGMS when it had 1–2 engineers; the product is host-automation SaaS across Airbnb, Vrbo, and Booking.com. A long-lived integration-heavy codebase behind a platform managing ~400,000 listings across 130+ countries. Stack: PHP, JavaScript, React, TypeScript, MySQL, Redis, Elasticsearch, ZeroMQ, AWS, Docker, with Laravel in the AI microservice.

Senior Full-Stack Developer · February 2017 – Present

Designed and shipped the daily-use AI orchestration: a multi-agent code-review skill (parallel reviewers, supervisor synthesis), a multi-stage ticket-investigation skill (parallel investigation, synthesis merge), and a QA test-plan generator.
Added LLM-as-judge validation across these skills to catch regressions in their output as prompts and models change.
Maintain the AI agents microservice that drafts and auto-sends host-guest messages in production, on an OpenAI-API-backed Laravel host service.
Hardened its function-calling reliability with JSON-schema-constrained output, per-provider validation, application-layer trace logging, and human-gated trace review.
Develop full-stack across the JavaScript/TypeScript/React frontend, the PHP backend, and the partner-platform API integration layer (Airbnb, Vrbo, Booking.com): feature work, architecture changes, and production bug-fix.
Built AI-search visibility (LLMO / GEO) on the company Ghost CMS marketing site so it surfaces in AI-assistant answers: llms.txt, schema markup, page-speed tuning.

Tier 3 Support Team Lead · August 2019 – Present

Diagnose long-running production bugs that need historical codebase context — ~100 personally resolved per year, sustained since 2019.
Lead the Tier 3 product support team from its founding, run flat with direct communication across engineering, CX, and product.
Mentored 6 junior engineers to mid-level over their first years on the team, managing 2–4 concurrently.

Technical Product Owner · October 2021 – Present

Triage bug fixes and tech-debt by customer-impact signal from support data, partner-platform error rates, and engineering effort estimates.
Bring the support team's view of recurring customer problems (the ones raw metrics miss) into engineering planning.
Automated cross-team reporting to Slack — KPI reports, priority summaries, meeting recordings, and AI-generated digests posted to engineering and CX channels.

Tier 3 Support Engineer · May 2019 – August 2019

Investigated bugs at code level while processing CX-team tickets — established the patterns later formalized in the Tier 3 Lead function.

Intelligentum, LLC · Contract · US (Remote) · September 2014 – January 2017

Full-Stack Developer · September 2014 – January 2017

Developed a CRM platform for an educational organization, building modules and fixing defects in PHP, JavaScript, Yii Framework, and MySQL.
Built internal-API integrations across the Yii backend.

InfoRegion LTD · Full-time · Ukraine · October 2009 – March 2012

Ukrainian web agency. Promoted from Back-End Developer to Lead Back-End Developer at the 9-month mark.

Lead Back-End Developer · Hybrid · June 2010 – March 2012

Led back-end on multiple PHP CMS platforms; built a freelancer portal for construction contractors on Yii.
Trained newly hired developers on feature implementation patterns.

Back-End Developer · On-site · October 2009 – June 2010

Built Joomla components with JavaScript front-end interactions, WebAsyst e-commerce stores, and sub-modules for the in-house CMS.

Personal Projects

bigcats.org.ua — Multi-Agent News Pipeline · 2022 – Present

Sole architect and engineer · Multi-agent pipeline since early 2025

Built a six-model pipeline across four providers.
Route each stage to a model chosen for the job, with Qwen3 and GPT-5-nano alternating on species classification and region tagging, Gemini 3 Pro translating to Ukrainian, and GPT-5-mini applying the edits.
Reserve Claude Opus for the deepest escalation tier, and bound the GPT-5 quality-loop analyzer to control cost and prevent runaway iteration.
Run an iteration-bounded translation-quality loop that doubles as a multi-model eval; human-gated publishing since the pipeline automated in early 2025.
Rebuilt retrieval around Google News RSS and GDELT in 2026, following NewsCatcher's own engineering guides; fall back through OpenRouter, with Nebius serving Qwen, so no vendor outage or credit-balance dip breaks the daily run.
Fan out each Telegram post to X, Bluesky, and Friendica (Fediverse) through custom orchestration, splitting long posts into platform-native threads and tracking replies across platforms.

Stack: PHP, Laravel, Filament, Claude / GPT / Gemini / Qwen, Telegram / X / Bluesky / Friendica platform APIs.

Data sources: Google News RSS, GDELT.

Live: bigcats.org.ua

Repos: github.com/Abysim/bigcats (site) · github.com/Abysim/api (pipeline)

Education

Kherson National Technical University · 2004 – 2009

Master's, Software Engineering · 2008 – 2009 · With Honors. Neural-networks research and a statistical-indicator-prediction thesis in C# / .NET.

Bachelor's, Computer Science · 2004 – 2008 · With Honors. Library-process automation thesis in C# / ASP.NET. International and regional programming contests.

Kherson Physical-Technical Lyceum · 2001 – 2004

Research-track lyceum, competitive entry. Second-degree diploma, All-Ukrainian Minor Academy of Sciences research competition (astronomy section, 2004).

Languages

Ukrainian (native) · Russian (bilingual) · English (professional)