Alexandr – React, Typescript, JavaScript

A large-scale back-office web application built for a major online retailer in the US, comparable in complexity to platforms used by companies like Amazon. The system serves as the operational backbone of the business, centralising and automating order management across high transaction volumes.

While the core goal sounds straightforward, the real challenge lies in handling massive datasets, deeply nested tables, and multi-panel workflows required by back-office teams. The application enables operators to organise, document, track, and manage orders efficiently through a highly interactive, data-dense UI with side panels, contextual actions, and real-time updates.

To support this complexity and ensure long-term scalability, the team designed and built a custom UI component library on top of Mantine, tailored specifically for internal operations and heavy data interaction. The result is a robust, maintainable back-office system that significantly reduces manual effort, improves operational visibility, and scales with the retailer’s growing business.

• Worked in a full-stack team that designed an architecture and delivery of a mission-critical back-office system handling high data volume and complex operational workflows.

• Designed and implemented highly complex, multi-layered UIs, optimising rendering and interaction performance for data-dense screens with nested tables and side panels.

• Built and scaled a custom UI component library on top of Mantine, ensuring consistency, reuse, and long-term maintainability across the platform.

• Owned high-load backend integration, coordinating frontend and backend logic to ensure stability, responsiveness, and data integrity under heavy usage.

• Supported the product end-to-end from development to production, resolving performance bottlenecks, stabilising releases, and ensuring smooth go-live and operation.

A modern transportation management web application (PWA) built for a leading logistics company in Northern Europe, designed to replace deeply outdated legacy software originating from the 1990s. The goal of the project was to modernise daily operations for both drivers and logistics managers, while operating reliably in real-world conditions.

A critical requirement was offline-first PWA functionality, as drivers frequently work in areas with unstable or limited internet connectivity. The application was designed to remain fully usable in low-connectivity environments, synchronising data seamlessly once a connection becomes available.

I was responsible for delivering a mobile-first experience tailored to drivers in the field, as well as intuitive management tools for dispatchers and operations managers. Prior to the new system, managers were overloaded with manual processes and fragmented workflows. After rollout, operational overhead was significantly reduced, decision-making became faster, and the company gained the capacity to scale operations and support growth with confidence.

The project combined strong UX, reliability, and performance to turn logistics operations from a bottleneck into a competitive advantage.

• Led full-stack system design for a mission-critical transportation platform, owning frontend architecture and backend integration strategy end-to-end.

• Designed complex integration with a legacy database, bridging a modern PWA with an old data model while preserving data integrity and operational continuity.

• Co-architected backend services and synchronisation logic with a backend engineer and DB architect, enabling reliable operation in offline and low-connectivity conditions.

• Delivered mobile-first, offline-ready workflows that replaced manual dispatcher and driver processes and unlocked operational scalability.

• Drove architectural and team process improvements, improving cross-team alignment, delivery predictability, and system maintainability.

A large-scale advertising management platform built for US-based marketing and advertising agencies operating high-volume campaigns. The product enables teams to launch, manage, and optimise hundreds of ads and campaigns in parallel, replacing slow, manual workflows with streamlined, data-driven operations.

A key capability of the platform is bulk campaign creation via Excel uploads, allowing agencies to configure and deploy multiple campaigns in a single action — a critical requirement for fast-moving performance marketing teams. The system supports complex campaign structures, intensive data processing, and continuous activity tracking across accounts.

As a Senior Frontend Engineer, I contributed to building a robust, high-performance web application capable of handling large datasets, frequent user interactions, and enterprise-level usage patterns. The focus was on scalability, responsiveness, and usability — ensuring the platform remains reliable and efficient even under heavy operational load.

• Led a full UI/UX redesign of a large, data-heavy advertising platform used by US marketing agencies.

• Delivered high-impact features, including bulk campaign creation via Excel uploads, enabling large-scale ad launches.

• Planned and executed safe frontend migrations, upgrading the app to newer Angular versions without disrupting active users.

• Improved stability and code quality by debugging complex issues, introducing unit tests, and hardening critical flows.

• Ensured pixel-perfect implementation by validating Figma designs and maintaining UI consistency across the product.

A full-scale parking management platform with web and mobile applications (iOS & Android). The product connects drivers and parking space owners in a single marketplace, allowing users to book nearby parking in real time or rent out their own parking spaces with minimal friction.

The platform is designed to serve both individual users and enterprise clients. Alongside consumer bookings, it supports large partners such as supermarkets and commercial property owners, offering tools for parking inventory management, availability control, and demand-driven utilisation of parking assets.

Built as a high-traffic, multi-platform service, the application focuses on reliability, ease of use, and scalability. It combines intuitive UX for everyday drivers with robust administrative and operational features required by large businesses, turning parking into a flexible, data-driven service rather than a static infrastructure.

• Designed the frontend architecture for a cross-platform parking marketplace (web, iOS, Android), ensuring scalability for both consumers and enterprise clients.

• Aligned closely with backend teams on API contracts and data flows, enabling smooth integration of booking, availability, and rental features.

• Built and led the frontend team, including hiring, onboarding, and day-to-day technical leadership.

• Maintained high engineering standards through code reviews, technical guidance, and hands-on problem solving.

• Owned delivery of complex features and critical bug fixes, while estimating and planning new functionality with product and stakeholders.

Petal is a cutting-edge AI-driven document analysis platform that transforms how professionals engage with research and technical content. It enables users to upload, organize and manage PDFs and HTML files, then interact with them intuitively — compare sources, search across multiple documents at once, and extract deep insights with precision. Petal’s context-aware AI empowers users to query, summarise, and navigate complex scientific material faster and more accurately than traditional tools.

I joined Petal at an early stage and played a central role in its development and growth. I led the end-to-end build of the application from concept to launch, architecting high-performance document workflows using React and AG-Grid to handle intensive data manipulation and multi-document interaction. My contribution was instrumental in shaping core features that deliver tangible productivity gains for researchers and corporate knowledge workers.

-Led the frontend architecture and delivery of a complex, Google-Docs-level web application, owning the UI from early MVP to a scalable production system.

• Designed high-performance document workflows Implemented advanced multi-document viewing, comparison, and search experiences for large PDF/HTML files, ensuring speed and stability under heavy data loads.

• Optimised data-heavy interfaces at scale Integrated and customised AG-Grid to handle complex tabular and document-derived data with excellent performance and usability.

• Owned frontend architecture and code quality Defined component structure, state management patterns, and performance best practices, keeping the codebase maintainable as the product and team grew.

• Acted as a product-minded engineering leader Worked closely with founders and stakeholders, translating ambiguous product ideas into clear, shippable UI solutions that directly improved user productivity and retention.

A large-scale trading and investment web application developed for a major Swiss bank, comparable in scope and complexity to platforms like Interactive Brokers. The platform provides users with access to a wide range of financial instruments, including forex, currency exchange, securities, stocks, crypto assets, and advanced trading tools.

My team and I were responsible for analytics and insight-driven modules used by active traders to make informed decisions in fast-moving markets. One of the key contributions was the rapid delivery of a crypto analytics module during a gold–crypto market surge. From concept to production, the module was designed, built, and launched in under 2 months.

The impact was immediate and measurable: within the first month after release, the module generated over $10M in revenue for the company. The work required close collaboration with product, data, and backend teams, as well as a strong focus on performance, accuracy, and reliability under real-time trading conditions.

• Led a cross-functional team (4 FS devs, 1 QA) delivering high-stakes analytics modules for a Swiss banking trading platform under strict quality and reliability requirements.

• Designed and delivered microservices end-to-end - from architecture and UI to testing and production - contributing to a modular system of ~80 services.

• Built multiple core services from scratch (5+ owned end-to-end), and supported delivery of additional services within a complex, Lego-style architecture.

• Modernised critical applications by upgrading React from v14 to v16 across key services, improving performance, stability, and maintainability.

• Enabled platform scalability and reuse by integrating new apps into the core trading platform and developing shared client libraries (NPM packages, UI components).