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Daniil Olekh

Full-Stack TypeScript Developer

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Full-stack TypeScript developer with about three years of commercial work. I take products from an empty repo to real users: React, Next.js and TanStack on the front, Node or Bun with PostgreSQL and Drizzle on the back, CI/CD and observability around it. Built an ed-tech platform solo that British teachers use today, built and deployed sportmagaz.com.ua (a store with its own admin panel) on my own, and shipped wallet, bonus and identity services for a live iGaming platform. Claude Code daily, everything reviewed.

Experience

  1. Software Engineer (contract) · iGaming platform

    2026 · Remote

    • Built event-driven Node.js microservices for a live iGaming platform (identity, gateway, wallet, bonus, casino, notification): Express, Drizzle ORM, PostgreSQL, Redis, Docker, GitLab CI.
    • Shipped per-brand GEO access rules end to end: schema, the shared decision function, gateway counters, monitoring alerts on threshold crossings, admin CRUD and the React admin UI.
    • Money-correctness work: idempotent withdrawals keyed on the ledger index, single-statement bonus expiry with debit, abuse limits on bonus issuance, campaign dry-run calculation with per-user exclusion reasons.
    • Built consolline.com solo: a four-language Astro site with WebGL2 animation, checked against Figma with pixel diffs.

  2. Full-Stack Developer · Freelance (Upwork)

    Jan 2026 – Aug 2026 · Remote

    • Rebuilt an agriturismo website on Astro, Tailwind and Strapi (IT/EN i18n, role-based CMS access, Vercel + Railway): mobile PageSpeed 69 → 99, load time ~16 s → under 2 s, 5.0 client review. Case study: danolekh.com/p/oasi-kadir
    • Reverse-engineered the parallax carousel, card carousel and menu animation from the old site's minified WordPress bundle (no source available) and reimplemented them 1:1.
    • Found and fixed hosting-compliance and DNS issues during the migration unprompted; full handover docs with everything under the client's own accounts.

  3. Founding Engineer · Quextro

    Dec 2024 – Dec 2025 · Remote

    • Built the entire ed-tech platform solo: Bun + Effect.ts + Drizzle ORM on the back, React 19 + TanStack Router on the front. Used today by British teachers and students.
    • Designed the core LLM pipeline that extracts questions and topics from PDF exam papers, with Zod-validated output and retries when the model returns something wrong.
    • Owned CI/CD, Docker containerization and OpenTelemetry observability on AWS and Railway.

  4. Full-Stack Developer · Freelance

    May 2024 – Dec 2024 · Remote

    • Built and deployed sportmagaz.com.ua solo, a sports-equipment store for Ukraine: Next.js 14, tRPC, Drizzle ORM and PostgreSQL, with a custom admin CMS for 2,000+ products (roles, specs editor, S3 image manager), attribute filters with live counts, Nova Poshta delivery lookup and Telegram order alerts.
    • Re-platformed it in 2026 to static Astro on Cloudflare Workers: view transitions that morph the product photo into its page, prices re-checked on the server by an Effect checkout worker.
    • 90+ Real Experience Score and steady organic SEO traffic (JSON-LD, sitemap, Google Merchant feed).

  5. Software Engineer · Radency

    2023 – 2024 · Kyiv / remote

    • Optimized a multi-tenant system (React, Express, Firebase) serving 10,000+ active users.
    • Built internal Vue/NestJS tools and Chrome extensions used daily by the HR department.

Projects

  • Azulejo (azulejo.danolekh.com): Ceramics storefront on TanStack Start + React 19, Drizzle + PostgreSQL, deployed on Cloudflare Workers (Hyperdrive), R2 media pipeline with sharp and blurhash, Strapi-backed journal, Vitest.

Open source

  • opentui, the terminal-UI library opencode is built on. Merged PR #558: browser-like text selection in textareas and a viewport-change selection bug fix.
  • code-racer, top contributor in 2023 (WebDevCody): multiplayer race rooms feature plus several fixes.

Skills

Languages
TypeScript, JavaScript, Python, SQL
Frontend
React 19, Next.js (App Router), TanStack Start / Router / Query, Astro, Tailwind CSS, View Transitions, WebGL2, Zustand, Radix / Base UI, Vite
Backend
Node.js, Bun, Express, Hono, Effect.ts, tRPC, REST APIs, webhooks, Zod, event-driven services
Data
PostgreSQL, Drizzle ORM, Redis, SQLite, S3 / R2
Infra
Docker, GitHub Actions, GitLab CI, Vercel, Cloudflare Workers, AWS, Railway, OpenTelemetry
Other
Strapi, Core Web Vitals / performance, SEO, i18n, LLM integration, Vitest, Claude Code daily (1+ yr)

Education

BSc Computer Science, Taras Shevchenko National University of Kyiv (2022 – 2026)

Languages

Ukrainian (native), Russian (fluent), English (B2), German (beginner)