
Sacha Leonel Lifszyc
Verified Expert in Engineering
Software Developer
Buenos Aires, Argentina
Toptal member since July 26, 2024
With over a decade of experience in the software development industry, Sacha is an experienced senior front-end engineer specializing in React, TypeScript, and GraphQL. His 4-year tenure at Toptal's core team highlights how his exceptional technical leadership and dedication have helped decrease thousands of talents activation time and boost scheduled interviews conversion rate. Sacha's versatile portfolio demonstrates his ability to enhance projects with expert precision.
Portfolio
Experience
- JavaScript - 10 years
- Front-end - 10 years
- React - 7 years
- GraphQL - 7 years
- TypeScript - 7 years
- Storybook - 4 years
- Node.js - 4 years
- Tailwind CSS - 1 year
Availability
Preferred Environment
MacOS, Visual Studio Code (VS Code), Chrome
The most amazing...
...products I've worked on are web applications for Toptal's core team that helped accelerate talent activation and candidate introduction processes.
Work Experience
Principal Front-end Engineer
Toptal
- Streamlined the profile activation process for thousands of talents, decreasing their time to market within the talent network by more than 35%.
- Enhanced the talent presentation process to clients by developing a web application from scratch that highlights talent profiles' most relevant parts for specific job descriptions, improving scheduled interview conversion rates by 5%.
- Contributed to the development of 10+ robust UI components for public use, featuring excellent component APIs that enhanced functionality and user experience.
- Headed over 15 initiatives that seamlessly integrated new features into web applications, consistently delivering high-quality enhancements.
- Introduced and advocated for component-driven development across multiple teams, significantly improving code maintainability and readability and the engineers' overall happiness.
- Promoted from senior to principal front-end engineer in recognition of outstanding leadership and technical contributions to the company.
- Trained a team on React Final Forms, reducing development time for form-related features, enhancing overall productivity, and strengthening team collaboration, communication, and trust.
- Led the development of a new UI component that showcased the overlapping working hours between a client and a talent in two different time zones, which received excellent feedback from our clients and matchers.
- Reorganized the Storybook documentation and standardized page sections, simplifying the developer experience and reducing development time.
- Participated in the front-end advisory board, engaging in strategic discussions that had a significant, company-wide impact on technology and application design decisions.
Full-stack Bootcamp Instructor
Digital House
- Led two full-stack software development courses at a top tech institute in Buenos Aires.
- Instructed over 40 students with little to no prior software development experience on building web applications through practical examples.
- Addressed student questions and assisted in correcting practical essays.
Senior Front-end Lead Engineer
Restorando
- Directed the web application migration from a Rails monolith to a React-based architecture, significantly modernizing the platform and enhancing performance.
- Developed a new photo carousel for displaying restaurant pictures, enhancing the platform's visual appeal and user engagement.
- Collaborated with the search engine optimization (SEO) department from MercadoLibre, validating a strategic roadmap that improved SEO positioning and organic traffic.
- Initiated and executed a 360-degree photography project for several restaurants, incorporating immersive visuals into restaurant pages as an experimental feature to enhance user experience.
- Improved conversion rate by 2% for selected Colombian restaurants through a personal initiative to enhance their photographic content during a business trip.
- Created a special San Valentine's Day landing page and advertisement featuring a curated selection of restaurants, which included personal involvement in video production and website design.
Senior Full-stack Lead Engineer
Democracia en Red
- Developed key features for our main web application, like sign-in, voting, and commenting for a civic engagement platform.
- Built new functionalities, including likes, dislikes, and replies, enhancing user interaction.
- Selected by Y Combinator for their inaugural batch of nonprofit organizations, recognizing our innovative approach to civic engagement.
- Deployed tailored instances for local congresses and municipal departments, customizing user experiences to meet specific needs.
- Presented software at the Buenos Aires City Congress, demonstrating real-world legislative application.
- Enabled global use with unexpected forks, including a Turkish version of the platform.
- Collaborated with European NGOs in Berlin to enhance global citizen participation.
- Utilized Segment.io and Google Analytics to refine user engagement strategies.
- Guided the DemocracyOS project as senior full-stack lead engineer, overseeing expansion and adaptation.
- Deployed and maintained the platform on Heroku, ensuring smooth operation and scalability.
Experience
Toptal Public Pages UI Components Library
Job-specific Resume Page
A key challenge was creating an interactive UI component displaying overlapping working hours between clients and talents across different time zones. My leadership in designing and implementing this feature was crucial, involving resolving complex product issues related to time overlap visualizations. This component was highly praised for its interactivity and effectiveness, significantly contributing to its success.
The redesigned, responsive page improved the user experience and increased the conversion rate of scheduled interviews, demonstrating a substantial enhancement in how talents were introduced to potential clients.
Talent Profile Application
Talent Testing Platform
My key contributions included implementing a feature that allowed for grouping questions into sections, which could be sorted, renamed, and organized as needed. Additionally, I developed an events timeline that recorded and displayed various activities during a candidate's test session. This timeline was crucial for monitoring and flagging suspicious activity, enhancing the integrity and oversight capabilities of the testing platform for administrators.
Talent Desktop Application
These enhancements improved the application's functionality and user interaction, enabling talents to adjust profile settings and providing direct links to essential web-based resources. Thus, the process for talents to act swiftly on potential job opportunities was streamlined.
Restorando Web Application
This strategic overhaul modernized the technology stack and significantly enhanced the user interface and user experience. The successful migration led to more agile development processes and a robust platform capable of handling increased user traffic and complex functionalities.
DemocracyOS
https://github.com/democracyos/democracyosCivicStack
https://github.com/CivicStack/civicstackEducation
Engineer's Degree in Software Engineering
National Technological University - Buenos Aires, Argentina
Certifications
CSS for JavaScript Developers
Josh W. Comeau
Learning GitHub Actions
Certified Scrum Master
Scrum Alliance
Skills
Libraries/APIs
React, React Testing Library, React Router, Node.js, Apollo Client, React Final Form, Moment.js, REST APIs, Playwright, Zod, Segment.io
Tools
GitHub, Git, NPM, Jira, Sentry, Google Analytics, Webpack, Apache, Browserify, Stylus, Gulp
Languages
JavaScript, HTML, CSS, TypeScript, GraphQL, ANSI C, Python, Ruby, Groovy, Prolog, Haskell, Smalltalk, PHP
Frameworks
Chrome, Jest, Express.js, Cypress, Yarn, Redux, Material UI, Ruby on Rails (RoR), Tailwind CSS, Electron, Laravel
Paradigms
Requirements Analysis, Scrum, Component-based Development, Search Engine Optimization (SEO), Object-relational Mapping (ORM), Database Design
Industry Expertise
Teaching
Platforms
FinalForms, Heroku, MacOS, Visual Studio Code (VS Code)
Storage
Databases, MongoDB, Datadog, MySQL
Other
Software Development, Software Analysis, System Requirements, Functional Requirements, Technical Requirements, Education, Front-end, Web Development, Full-stack, API Integration, User Requirements, System Design, GraphQL Code Generator, Technical SEO, Web Accessibility, Styled-components, Storybook, Software Design, Leadership, Technical Leadership, Accessibility, Object-oriented Databases, Full-stack Development, MVC Frameworks, Operating Systems, OSI Model, Business Planning, Data Structures, APIs, Design Systems, GitHub Actions, Google Analytics 4, Monorepos, Amplitude, Open Source
How to Work with Toptal
Toptal matches you directly with global industry experts from our network in hours—not weeks or months.
Share your needs
Choose your talent
Start your risk-free talent trial
Top talent is in high demand.
Start hiring