Person coding on his laptop
Available for new Projects

Koustubh Lapate

I build scalable, production-grade web and AI-powered systems for startups and global clients. With 3+ years of freelance experience, including work with a YC-backed startup, I help teams ship faster and smarter.

Experience

Freelance Software Engineer

Braintrust · Freelance

Jul 2024 - Present

  • Designed and developed robust, reusable UI components in React, reducing redundancy and improving maintainability.
  • Enhanced frontend performance with efficient state management and optimized rendering, improving load times and user experience.
  • Wrote clean, well-structured code with comprehensive unit and integration tests, ensuring reliability and smooth deployments.

Freelance Software Engineer

Upwork · Freelance

Nov 2022 - Present

  • Developed 30+ reusable UI components using React.js, Next.js, TypeScript, and Tailwind CSS, improving frontend efficiency by 40%.
  • Enhanced website performance, reducing load times by 25% through server-side rendering (SSR) and static site generation (SSG) in Next.js.
  • Optimized JavaScript execution, reducing bundle size by 30% using code splitting and lazy loading.
  • Refactored and modularized legacy JavaScript codebases, improving maintainability and reducing redundancy.
  • Built RESTful APIs with Node.js (Express.js), implementing middleware-based request handling for clean, scalable architecture.
  • Created robust test cases using the React testing library, ensuring high code coverage and maintainability.
  • Maintained high code quality by enforcing ESLint, Prettier, and best practices, reducing bugs and improving team collaboration.

Freelance Software Engineer

The Hog (YC F25) · Freelance

Dec 2025 - Feb 2026

  • Led end-to-end development of core platform features across search, enrichment, AI personalization, and onboarding, owning architecture, implementation, and production delivery.
  • Architected a multi-provider scraping and search infrastructure using a waterfall routing strategy, reducing web data costs from ~$2.9K/month to ~$430/month (~85% cost reduction) while improving reliability and fallback coverage.
  • Built a high-impact AI-driven Voice Profiles feature that analyzes LinkedIn, X, Reddit, and long-form content to generate personalized brand voices and tone, enabling high-quality AI-written replies aligned with each user’s writing style.
  • Designed a scalable people enrichment and persona pre-filtering pipeline combining SQL-based hard filters and targeted enrichment providers, significantly reducing unnecessary AI classification and enrichment spend.
  • Shipped multiple high-impact product features including LinkedIn quote reposts with AI commentary, onboarding AI copilot experiences, and automated email workflows for user activation and engagement.
  • Improved platform stability and UX by resolving critical production issues, optimizing enrichment pipelines, and standardizing design systems across the app.
  • Collaborated closely with founders and product leadership, translating ambiguous product ideas into shipped, measurable outcomes in a fast-moving startup environment.

Contact Me