Dmitrii Frolov

A gamified EdTech app where kids practice English with a voice AI tutor, daily quests and rewards between live lessons.

Technologies: Python, LiveKit Agents, WebRTC, Google Gemini Live API, Alibaba Qwen Omni Realtime, TypeScript, React, Module Federation, PostgreSQL, Directus (headless CMS), GrowthBook, Langfuse, BigQuery, Playwright, AWS, GCP, Jenkins, Sentry, Kibana, Workato

• Built and own the Python/LiveKit agent harness behind up to 10,000 daily voice sessions, letting a real-time voice model drive the React UI via tool calls, turning conversation into game-like practice.
• Enabled the AI tutor's China launch by adding Alibaba Qwen alongside Google Gemini, and removed lags in role-play conversations by routing each activity to its best-fit model.
• Introduced an LLM evaluation framework: AI-simulated students run voice sessions, and Langfuse experiments with LLM-judge and code evaluators compare prompt variants against control.
• Made the agent's quality measurable in production with LLM observability: latency, tool-call errors and guideline-breaking replies caught by rule-based checks and an LLM judge.
• Co-designed and shipped a new home screen with personalized quests to build a daily learning habit.
• Designed the content model and data contracts between the CMS and the voice agent, so new scenarios, goals and prompts ship as CMS data and non-engineers launch activities without a release.
• Covered student app flows with Playwright e2e tests and a coverage list generated from the specs, with stable scenario IDs for QA and a CI drift check.

A Travel & Hospitality SaaS booking platform that aggregates hotel, flight and event inventory from multiple suppliers into one search and booking flow.

Technologies: Next.js, React, TypeScript, Tailwind CSS, Storybook, Node.js, NestJS, Kafka, Redis, Lighthouse, GitHub Actions

• Reduced Total Blocking Time by 80% (4.2s → 0.84s) and eliminated Cumulative Layout Shift by optimizing the Next.js SSR pipeline, raising the Lighthouse performance score by 33 points.
• Built event-driven microservices on Kafka that aggregate inventory from multiple suppliers, normalize it into a unified schema and deduplicate listings, serving fast search from Redis.
• Integrated third-party supplier APIs behind a unified NestJS API layer with retries, rate limiting and response caching.
• Built the component library with Tailwind CSS and Storybook with 100% auto-generated documentation coverage, streamlining design-engineering collaboration.
• Integrated Lighthouse checks into the GitHub Actions pipeline with automated reports, enabling continuous performance monitoring and early regression detection before production.
• Delivered features end-to-end, owning both frontend and backend with Node.js and NestJS.

A MarTech & e-commerce SaaS platform used by 58,000+ marketers and brand owners to build website forms, pop-ups and promo widgets in a no-code editor and run email marketing campaigns.

Technologies: TypeScript, React, Redux & RTK, Single-SPA, AngularJS, Webpack, Google Charts, Node.js, Python, FastAPI, PostgreSQL, GrowthBook, JWT, webhooks

• Built a full email marketing toolkit (campaign builder, editor and third-party integrations), reducing time-to-launch from days to minutes; the company's own marketing runs on it, delivering ~150k emails a month at 98.9% deliverability.
• Built and launched a free no-signup Popup Builder on Product Hunt as a product-led growth channel, with a live-preview editor, timing, scroll and exit-intent triggers and one-snippet embedding.
• Built the onboarding flow for new users, improving early engagement and reducing first-week churn.
• Integrated A/B testing into the platform with feature flags and experiment tracking, enabling data-driven optimization of CTAs and onboarding flows that improved conversions.
• Redesigned the platform dashboard and its navigation architecture so users reach any feature within 3 clicks, improving overall product usability.
• Introduced a structured code review process and automated linting standards, cutting the release cycle from monthly to weekly and keeping post-release regressions below 5%.
• Migrated the legacy AngularJS codebase to React and RTK using a Single-SPA micro-frontend architecture, reducing Total Blocking Time by 60%.
• Built a statistics dashboard with geo-charts and time-series visualizations using Google Charts.
• Migrated authentication from session cookies to JWT tokens, reducing server load and enabling instant dashboard access without page reloads.
• Added click-to-configure interaction to the WYSIWYG editor, giving users single-click access to any widget element's settings and significantly speeding up editing.
• Optimized the Webpack build pipeline through bundle splitting, tree shaking and dependency cleanup, reducing build time by 60%.
• Built an integrations layer connecting the platform with third-party email marketing services via webhooks for real-time data sync.
• Redesigned the token system and style architecture for pixel-perfect components across the platform.

An EdTech online English school for kids with one-on-one video lessons in the browser, an interactive whiteboard with games and animations, and device checks before each lesson.

Technologies: WebRTC, Kurento, Node.js, WebSockets, Jenkins, AWS EC2, Lokalise

• Led and mentored a micro-team of 3 engineers, delivering the MVP in 4 months and establishing the technical foundation of the platform.
• Researched and integrated the open-source Kurento media server, enabling WebRTC video calls in the browser and accelerating the first product launch.
• Designed and built a real-time video communication platform with WebRTC and Node.js from scratch, scaling to 1,000+ concurrent active sessions per day.
• Built a real-time collaborative whiteboard with multi-user interaction, animations and visual effects, synchronized across participants via WebSockets.
• Built a pre-lesson camera, microphone and connection check, reducing lesson cancellations by 40%.
• Set up Jenkins CI/CD with multi-environment staging on AWS EC2, eliminating manual release steps.
• Integrated Lokalise for i18n automation, reducing translation preparation time for new features by 3x.
• Grew into the Tech Lead role, doubled the engineering team and established development processes and code review standards that cut the release cycle from monthly to weekly.

A white-label cloud storage platform (Cloudike) that telecom operators like Vodafone offer to subscribers.

Technologies: AngularJS, Backbone.js, jQuery, SSO, i18n, Accessibility (WCAG)

• Designed a deeply customizable frontend architecture for the core product Cloudike, used by millions of users across multiple operators.
• Built web and mobile clients on that architecture, shipping a branded version for each operator.
• Built an SSO client for seamless authentication across all platforms.
• Implemented i18n support for multiple languages across all operator markets.
• Ensured WCAG compliance across all platform interfaces for users with disabilities.

Major: Master of Computer Science and Engineering