Senior Software Engineer

Implemented peer-to-peer payment capabilities for a product serving more than 100 million users and 8 million daily active users. Built a request-money feature for Klarna and non-Klarna users in NestJS with a 200 ms performance budget, and integrated mission-critical Node.js microservices through GraphQL and distributed Kafka.

Improved product quality and operational stability through Playwright E2E and component tests, expanded RSpec coverage, and AI-assisted development workflows. Used DataDog, New Relic, Sentry, Sumo Logic, Kubernetes, and PagerDuty for observability and incident prevention; also reworked enterprise licensing, SSO with SAML/OAuth and 2FA, and CSV imports designed for more than 10 million records per month.

Worked with stakeholders and designers to reduce onboarding friction while maintaining accuracy in KYC and tax-document validation. Reduced user onboarding time by 25%.

Developed and maintained an Elixir/Phoenix application with a React frontend using GraphQL and React Query. Implemented parallel Cypress test execution on GitHub Actions, reducing deployment time by 50%.

Built and optimized AWS serverless services, including S3/Lambda image processing with Sharp and a streaming S3/Lambda unzip service. Reduced AWS costs by 35% through EC2, RDS, ElastiCache, S3 storage-tier, spot-instance, and auto-scaling optimizations.

Introduced a GraphQL API to replace a deprecated REST API, created a Node.js CLI for client application validation and deployment, and established JavaScript quality and test automation on GitHub Actions. Led company-wide E2E testing adoption, trained QA teams, and contributed frontend/performance articles, documentation, and the marketing website.

Maintained a Ruby on Rails application and delivered frontend functionality for financial workflows.

Implemented capitalization-table calculations in Vanilla JavaScript, processing complex equity structures used for 409A valuations.

Modernized a legacy frontend within three months while continuing to deliver assigned work. Reduced page-load time from 3.4 seconds to 1.9 seconds.

Mentored junior frontend developers and built custom interactive data visualizations, including organization charts, using D3.js and Highcharts.

Developed and maintained a post-login banking service using JavaScript.

Worked on financial-services software in a banking environment.