Sava Lazin — Senior Frontend Engineer

About

Over 12+ years in frontend engineering, I've worked on trading platforms, healthcare tools, ad-tech products, and DeFi apps with teams across Europe and the US. Most of my work is in data-heavy interfaces where speed and correctness both matter.

Vue and Nuxt are my core stack, and I've also shipped production code in React and Angular. I usually work on the hard parts: complex state, real-time rendering, and large migrations that need to stay stable while the product is live.

I also care about team systems. I've introduced frontend conventions that became team standards and led migration work that required tight coordination across product teams.

Outside of work, I'm usually trying new tools, reading about aviation or spending time with my daughter and wife.

What I work with

Tools I use most often

Vue & Nuxt

Core stack. I've led Vue 2 to 3 migrations on live products, built Nuxt 3 apps, and managed Pinia state for real-time features.

Vue 3 Nuxt 3 Pinia Vue 2 Vuex

React & Angular

Shipped React/Redux and Angular/NgRx. I can move across frameworks when the product requires it.

React Redux Angular NgRx RxJS TypeScript

Data Visualization

Built charting layers for crypto trading, energy and healthcare dashboards. I focus on clarity, performance, and stable real-time updates.

Chart.js ApexCharts TradingView Recharts Highcharts

Performance & Architecture

I focus on component boundaries, predictable state, and rendering paths that stay fast under real traffic.

Vite Webpack Component Design State Management

Styling Systems

I've built custom systems, set up BEM conventions, and shipped accessible UIs.

Tailwind Bootstrap SASS BEM ITCSS OOCSS Figma

Domain Knowledge

Most of my experience is in fintech/crypto and healthcare, where UI reliability and data accuracy are critical.

Trading Platforms Web3 / Solana Healthcare UIs Node.js

Selected Work

Projects with clear technical trade-offs and measurable outcomes

Migrating a Live Trading Platform from Vue 2 to Vue 3

Kriptomat had a large Vue 2/Vuex codebase with rising maintenance costs, but a rewrite was too risky on a live EU-regulated exchange. I led an incremental migration to Vue 3 and Pinia, module by module, while product work and updates continued.

Outcome

Completed migration to Vue 3 + Pinia with zero trading downtime for 500,000+ users
Reduced build times after adopting Vite; Pinia stores were simpler to maintain and test
Delivered migration across the full frontend surface with no feature freeze

Vue 3 Pinia Nuxt 3 Node.js

Modernizing a Legacy CSS Codebase with BEM, ITCSS & OOCSS

The product relied on a large, legacy CSS codebase that had grown organically over time. Styles were tightly coupled, overly specific, and difficult to extend without regressions. The accumulated technical debt significantly impacted performance and maintainability, contributing to slow page loads and unpredictable styling conflicts.

I led a structured refactor toward a clean, scalable architecture using BEM for clear component structure, ITCSS for layered organization, and OOCSS principles to improve reusability and separation of concerns. The migration was executed incrementally, allowing ongoing feature development without disruption.

Outcome

Reduced page load time by ~50% by removing unused CSS and optimizing render-blocking styles
Re-architected the styling system using BEM naming conventions and ITCSS layering
Applied OOCSS principles to increase reuse and reduce duplication across components
Improved maintainability, predictability, and onboarding for frontend developers
Delivered the migration progressively with no downtime or feature freeze

BEM ITCSS OOCSS Frontend Architecture Performance Optimization Refactoring

Healthcare UI with Compliance and Accessibility Constraints

MESI's FDA-cleared, CE-marked diagnostics platform is used by 20,000+ healthcare professionals across 50+ countries. The UI had to be accessible, data-dense, and reliable on desktop stations and tablets. I built reusable components with accessibility built in and worked with design/backend teams to preserve data integrity from API to UI.

Outcome

Compliant, accessible UI shipped and in daily use by 20,000+ clinicians across 50+ countries
Responsive component library handling data-dense diagnostic screens across mobile, tablet, and desktop stations
Part of a platform processing over 280,000 measurements annually

Vue 3 Pinia Tailwind Accessibility

Experience

Roles and shipped outcomes

Slovenia, Remote — May 2023 – Sep 2025

Led the Vue 2/Vuex to Vue 3/Pinia migration and CSS refactor on a live EU-regulated exchange used by 500,000+ traders across 30+ countries. Delivered it module by module with zero downtime, while product work and updates continued.

Vue 3 Nuxt 3 Pinia Chart.js ApexCharts Node.js

Ljubljana, Remote — Oct 2022 – Apr 2023

Built accessible UI for an FDA-cleared, CE-marked diagnostics platform used by 20,000+ healthcare professionals across 50+ countries. Created a responsive component library for diagnostic workflows and improved collaboration between design, frontend, and backend.

Vue 3 Pinia Tailwind Accessibility

Remote — Dec 2021 – Apr 2022

Built frontend features for a Solana DeFi fund management platform, including wallet flows, on-chain transaction feedback, and portfolio tracking with TradingView charts. Ramped up in the Solana ecosystem quickly and shipped production features within weeks. The platform later wound down during the 2022 market downturn.

React Redux TradingView Web3 / Solana

Copenhagen, Remote — Apr 2021 – Sep 2021

Built the Angular template engine for a dynamic ad platform used by brands like IKEA, Audi, and LEGO across 41 countries. Led migration to a newer framework version and refactored the codebase to improve performance, scalability, and maintainability while enabling high-volume ad rendering.

Angular 12 Tailwind

Slovenia — Sep 2018 – Jan 2020

Set up frontend architecture and BEM conventions for a crypto custody startup. Focused on high-risk flows involving private keys and multi-step confirmations. The patterns I introduced became the team standard before the company shut down.

Angular 8 BEM Figma

Earlier Experience

Condugo Front End Developer Jun – Aug 2018

Contract role on an EU-funded energy management platform for the petrochemical sector.

ICONOMI Front End Developer Feb 2017 – Jun 2018

Owned the front-end architecture, establishing standards, structure, and best practices for crypto asset management platform with 43K+ users in 161 countries.

RebelMouse Front End Developer May 2015 – Jul 2016

CMS platform powering publishers such as Axios, Earthables, and The Dodo (120M+ monthly reach). Spearheaded the end-to-end development of Earthables, building it from the ground up and launching to a pre-existing audience of 1M+ users.

Danulabs Lead Front End Developer Aug 2014 – Jun 2015

Promoted to my first lead role, where I built reusable HTML/CSS frameworks and jQuery plugins supporting six projects.

Freelance Front End Developer & Designer Sep 2013 – Aug 2014

Worked with international clients via oDesk, DesignCrowd, and 99designs.

Education

Technical School "Mihajlo Pupin"

Electronics — Novi Sad, Serbia

I started tinkering with code in the late '90s with IRC scripts, mIRC bots, and small websites. I moved into frontend professionally in 2013 and have shipped production code across 10+ codebases since.

Let's talk

If you need a senior frontend engineer or migration consulting, feel free to reach out.

Email me LinkedIn