Samuel Hrotik

Senior Full-Stack Engineer

Phone
+421 915 161 060
Email
[email protected]
Github
https://github.com/Hroco
Web
https://samuelhrotik.nexelon.sk/
Location
Nitra, Slovakia (remote-friendly)
LinkedIn
https://www.linkedin.com/in/samuel-hrotik-071399132/

Profile & Status

  • Senior Full-Stack Engineer focused on React & Next.js
  • 6+ years delivering web products, 5+ years leading scalable architecture and product direction
  • Founder and lead engineer at Nexelon s.r.o.

About Me

Senior full-stack engineer and software architect specializing in React and Next.js. I design and ship scalable applications with a focus on performance, developer experience, security, and maintainability.

I have deep experience with API contracts (tRPC/REST), state management (Zustand/TanStack Query), data layers (PostgreSQL, Drizzle ORM), authentication (NextAuth, Better Auth), and CI/CD on Google Cloud (Cloud Build/Run/SQL).

I lead technical direction, set code standards (ESLint/Prettier), and implement observability plus release processes in Turborepo monorepos.

Selected Achievements

  • Re-platformed multiple products to Next.js, cutting codebase size by 20–35% and speeding up build/deploy loops.
  • Standardized Turborepo setups and Google Cloud CI/CD pipelines (Cloud Build + Cloud Run).
  • Designed Drizzle data models with safe migrations/rollbacks and automated release gates.
  • Established reliable release processes with linting, tests, and preview deployments on every change.

Technology Stack

Frontend

Next.js, React, TypeScript, Tailwind CSS, Shadcn/UI, Zustand, TanStack Query, Responsive Design

Backend

Node.js, tRPC, PostgreSQL, Drizzle ORM, NextAuth.js, Better Auth, Serverless, API Design

Tools & Infrastructure

Git, Docker, Turborepo, Google Cloud (Cloud Run/Build/SQL), CI/CD, Monorepo

Additional Technologies

C++, Python, Electron, Qt, Stripe Integration, AI Integration, Cypress, Testing, Observability

Key Competencies

Architecture & System Design

Designing modular monorepos with domain modeling and API contracts, reducing technical debt and accelerating developer onboarding.

Performance & Scaling

Optimizing applications via SSR/ISR, caching, and code-splitting, improving LCP by 40–60% and reducing infrastructure costs.

Security & Auditability

Implementing secure auth flows, audit logs, and sensitive data handling, ensuring compliance and reducing data breach risk.

Developer Experience

Establishing automated CI/CD, strict linting, and release processes, cutting code review time by 50% and increasing delivery speed.

Re-platforming & Migrations

Leading re-platforming initiatives that reduce codebase size by 20–35% and accelerate build/deploy cycles while maintaining functionality.

Architecture Principles

  • Security best practices in auth/session flows, auditing, and handling sensitive data.
  • Modular domains with clearly defined boundaries and responsibilities.
  • Accessible, localized UI built on a consistent design system.
  • Code standards and conventional commits for predictable and maintainable codebase.

Languages

  • Slovak · Native
  • English · B2 – professional working proficiency

Work Experience

Development Engineer & PDF Specialist · Foxit

01/2025 – Present

Slovakia · Remote

Leading Tagged PDF School (PDF Association) on Next.js + tRPC hosted on Google Cloud, integrating C++ validation engines, and running CI/CD plus monitoring for a mission-critical PDF education platform.

Key skills: Next.js, tRPC, Google Cloud, PDF SDK, C++, Observability

Software Engineer · Foxit

10/2023 – 01/2025

Slovakia · Remote

Delivered web and cloud components, automated quality checks, introduced ESLint/Prettier standards, and strengthened CI steps across teams.

Key skills: React, TypeScript, Git, ESLint, Cloud Applications

Junior Software Engineer · Foxit

07/2022 – 10/2023

Slovakia · Remote

Built C++/Python tooling, integration modules, and cross-platform builds for PDF workflows.

Key skills: C++, Python, Cross-platform builds

Quality Assurance Engineer · Foxit

11/2020 – 07/2022

Slovakia · Remote

Owned testing strategy, automation, scenarios, and reporting across PDF products.

Key skills: QA Automation, Test Strategy, Reporting

Founder & Lead Engineer · Nexelon s.r.o.

2020 – Present

Slovakia · Remote

Tech lead for bespoke products—architecture, full-stack delivery, client communication, infrastructure, security, and SLAs.

Key skills: Tech leadership, Architecture, Client delivery, CI/CD

Developer · HIMA

06/2020 – 09/2020

Nitra Region, Slovakia

Developed FLOWorX pipeline system with leak detection in C++/Qt and modular extensions.

Key skills: C++, Qt, Systems design

Nexelon s.r.o. – Founder & Lead Engineer

Tech lead, architect, and full-stack engineer delivering custom products including infrastructure, security, and SLAs.

Responsibilities

  • Define architecture, domains, and delivery plans for both greenfield and re-platforming initiatives.
  • Lead client communication, roadmap prioritization, and shared code standards across teams.
  • Operate CI/CD on Google Cloud with automated testing, observability, and release guardrails.

Featured Projects

SplitWallet

https://splitwallet.nexelon.sk/

Expense-sharing platform with real-time sync, offline UX, and premium features backed by Stripe. Extensive automated E2E tests in Cypress.

Technologies: Next.js (App Router), tRPC, PostgreSQL, Drizzle ORM, Zustand, TanStack Query, Tailwind CSS, Cypress

Impact: Type-safe calculations and validations reduced settlement mistakes by ~30%; SSR/ISR keeps LCP and SEO fast.

Tempora – Attendance & Leave

http://tempora-demo.nexelon.sk/

B2B attendance system with check-ins/outs, vacation approvals, reporting, roles, and audit log. Extensive automated E2E tests in Cypress.

Technologies: Next.js, Tailwind CSS, Drizzle ORM, PostgreSQL, tRPC, Better Auth, Cypress

Impact: Modular domains with server actions, optimistic updates, caching, and accounting exports.

Inventory & Billing – Bakery

Re-platform from Node.js + Express + vanilla stack to Next.js + Styled Components to unify FE/BE delivery.

Technologies: Next.js, Styled Components, TypeScript, PostgreSQL

Impact: Higher type safety, faster time-to-feature, and reliable invoice/stock movement printing.

Delivery Notes – Electron + React

Desktop app with local storage, offline UX, sync modules, and robust printing.

Technologies: Electron, React, TypeScript

Impact: Guaranteed offline workflows for field teams while keeping data consistent across devices.

Warehouse Management – Creative Agency

Platform for material intake/issue, pricing, documents, and role-based access on Next.js + Drizzle.

Technologies: Next.js, Drizzle ORM, PostgreSQL, tRPC, Tailwind CSS

Impact: Secure role-based operations with auditable exports and predictable deployments.