Tetyana Pylat
Verified Expert in Engineering
Full-stack Developer
Lviv, Lviv Oblast, Ukraine
Toptal member since December 10, 2022
Tetyana is an experienced software engineer passionate about developing innovative programs. With her background spanning various projects in different domains, she is a confident communicator who thinks strategically, which helps her develop customized software to meet clients' organizational needs. Tetyana is a hardworking, responsible professional, a reliable team member, and eager to take on new challenges.
Portfolio
Experience
- C# - 9 years
- JavaScript - 8 years
- SQL - 8 years
- .NET - 8 years
- TypeScript - 4 years
- Redux - 4 years
- Material UI - 4 years
- React - 4 years
Preferred Environment
Windows, Next.js, GraphQL
The most amazing...
...project I've worked on is JustAnswer, an online question-and-answer platform that connects customers with experts.
Work Experience
Lead Software Engineer
JustAnswer
- Led the design and implementation of an internal prompt management tool for LLM‑powered products, improving how prompts are created, reviewed, and deployed to production.
- Integrated Promptfoo into the internal prompt management tool, enabling in‑tool prompt evaluation with configurable test suites and reducing friction for engineers running LLM evals.
- Contributed to the Promptfoo open‑source project by adding SharePoint support for storing and managing evaluation datasets, aligning internal workflows with existing company infrastructure.
- Investigated and evaluated modern LLM practices such as online evals, MCP, and observability and evaluation tools like Langfuse and Braintrust to enhance reliability, traceability, and monitoring of LLM‑powered features.
- Designed and evolved prompt approval gates (automated evals plus human review), improving the safety and reliability of prompt changes before they reach production.
Senior Full-stack Developer
JustAnswer
- Developed and maintained a web .NET/React application aimed to serve as a tool for bot development. I used Material UI, React hooks, Redux toolkit, and React hook forms.
- Transformed Figma designs into pixel-perfect React components and responsive layouts.
- Taught a group of 15 newcomers to use React and all its new features. Teaching consisted of lectures, live coding sessions, task assignments, code reviews, and giving feedback.
- Applied Scrum methodology through daily scrums, grooming, planning sessions, and estimations.
- Used Google Analytics and Microsoft Power BI tools on a daily basis.
Senior Full-stack Developer
APS Consultants
- Transformed client requirements into working solutions and provided support for the existing website.
- Designed an SQL server database, created a REST API using ASP.NET Core, and developed the UI as a React single-page app.
- Led the UI/UX design using the Material UI (MUI) library, satisfying the client's needs completely.
Middle Full-stack Developer
ABTO Software
- Conducted extensive A/B testing, including implementing experiments that required several versions of web pages, which differed in UI and functionality, and compared the conversion rate and other metrics of those pages.
- Used Google Analytics and Microsoft Power BI tools on a daily basis.
- Fixed software development issues that may arise in pre-production and production environments.
- Developed software design documents and reviewed their creation process.
- Applied Scrum methodology through daily scrums, grooming, planning sessions, and estimations.
Software Developer
Ericsson
- Developed a Python project to automate the configuration management routine in the GSM radio access network area.
- Performed the continuous integration (CI) environment operation and maintenance tasks for the TitanSim project.
- Participated in delivering a .NET project aimed to automatize business trip organization processes for employees.
Experience
JustAnswer
Alleye
https://www.apsinco.com/alleye-cmms-softwareI worked as a full-stack developer and built new features within a small international team using Scrum methodology.
Dialog Set Editor
I took part in the main development and was in charge of keeping the technologies up to date.
Education
Master's Degree in Economic Cybernetics
Lviv State Academy of Finance - Lviv, Ukraine
Skills
Libraries/APIs
React, REST APIs, Node.js, OpenAI API, React Router, React Redux, React Hook Form, Formik, LINQ
Tools
GitHub, Visual Studio, Google Analytics, Figma, Webpack, Jenkins, Redux Thunk, Git, Redux Toolkit, Ace Editor
Languages
SQL, C#, TypeScript, JavaScript, CSS, HTML, C#.NET, Sass, HTML5, JavaScript 6, Python, Bash Script, GraphQL
Frameworks
.NET, Redux, Material UI, .NET Core, Cypress, Jest, Swagger, JSON Web Tokens (JWT), ASP.NET Core, Next.js
Paradigms
Unit Testing, REST, Microservices, Role-based Access Control (RBAC)
Storage
Microsoft SQL Server, PostgreSQL
Platforms
Docker, Vercel, Windows, Linux, Typesafe, Azure
Industry Expertise
Cybersecurity
Other
Integration Testing, Front-end, UI Components, Web UI, Web UX, Full-stack, API Integration, Back-end, Web Applications, APIs, Front-end Development, Axios, Full-stack Development, SaaS, HTTP, Middleware, AI Tools, CI/CD Pipelines, Performance Optimization, AI Agents, Large Language Models (LLMs), Economics, User Experience (UX), User Interface (UI), Styled-components, Prompt Engineering, promptfoo, Vibe Coding
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