Doug S.

Doug S.

Mississauga, Canada
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About Me

Doug is a Senior Front-end Developer with with 10 years of experience delivering high-impact products to millions of users across diverse industries including fintech, legal-tech, insurance-tech, and web agencies. He specializes in front-end architecture and engineering leadership, with a strong focus on accessibility, user experience, and building scalable, maintainable codebases. Doug's expertise includes React development, client-side JavaScript experience, React UI knowledge, and familiarity with Design Patterns and responsive design. He crafts architectural and design solutions to enhance performance, security, and reliability. Doug makes high-level design decisions and writes scalable code to satisfy functional and non-functional requirements, implementing reusable UI components based on modern web tools and technologies.

AI, ML & LLM

Claude AI/ML AI Model Intergration

Frontend

Backend

Payment APIs PHP Rest API Express.js

Other

Work history

UpStack
UpStack
React.js Developer
2022 - Present (4 years)
, Remote
  • Creating and developing innovative fronted solutions for clients across a broad range of industries.

  • Participate in scrums consisting of cross-functional teams, both software and hardware.

  • Ensure that features are being delivered efficiently and on-time.

Self-Employed
Self-Employed
Software Engineering Consultant
2024 - Present (2 years)
Remote
  • Cut render time by 46% on a billion-user consumer platform, through targeted prefetching and preloading on hot paths.

  • Migrated a legacy React app to a TypeScript monorepo, establishing type safety and shared tooling across the codebase.

  • Led a cross-team frontend group, mentoring engineers and driving adoption of new architecture and patterns across projects.

JavaScriptTypescriptGo (Golang) Nodejs Web Performance Optimization (WPO) Cross-functional leadership Refactoring
Tally
Tally
Senior Web Engineer
2023 - 2024 (1 year)
Remote
  • Re-architected the Web SDK’s embedded iframe to serve multiple apps from configurable entry points, cutting new-feature dev time by 90%.

  • Led cross-team authentication design (sessions, cookies, rate limits) across Web and mobile SDKs in a compliance-heavy fintech environment handling SSN collection.

  • Integrated Plaid APIs for bank linking, credit-card listing, and identity verification in the Web SDK.

TypescriptReactJS SDK Development Auth handling Plaid API FinTech
Symend
Symend
Senior Software Engineer
2022 - 2023 (1 year)
Canada
  • Led frontend development for several core feature areas in a large-scale B2B platform migration.

  • Drove API contract design and feature specification, unblocking 6+ dependent engineering teams.

TypescriptJavaScriptNodejs ReactJS JSON REST APIs Playwright
XWP
XWP
Senior Software Engineer
2019 - 2022 (3 years)
, United States of America
  • Delivered frontend and full-stack builds for multiple large consumer brands, several reaching millions of monthly users.

  • Led a flagship brand site rebuild that lifted page views 30% with SEO and performance gains.

  • Unified a brand’s multi-site network into a single monorepo, partnering with their in-house frontend team.

Necara GmbH
Necara GmbH
Software Engineer
2016 - 2019 (3 years)
, Germany
  • Built an automated client onboarding flow that raised customer retention 20%.

  • Created a server-monitoring dashboard surfacing resource usage across a high-traffic SaaS product.

Showcase

React.js Developer - Featured Article Solution
React.js Developer - Featured Article Solution

Designed and implemented the components of a more special article type on a "Featured Article" solution for the client - manoeuvring around complicated design features using Figma to deliver a fully working page. Worked on a custom video player solution and innovative scroll animations that made the page interactive.

Lead Developer - New Blog Page Solution
Lead Developer - New Blog Page Solution

Led dev processes to redesign the blog page for a high-profile client - working on the entire frontend architecture of the blog to enhance performance and accessibility for users. Delivered high scores on Google's Web Vitals for Desktop (99) and mobile (>90) on the solution - focusing on accessibility for a user-focused solution.

Lead Frontend Engineer - Currency Tools Solution
Lead Frontend Engineer - Currency Tools Solution

Worked on dev processes to scope, set up and deliver the base architecture for the solution - designing and creating various currency tools for the website using React and Typescript. Implemented the currency tools to fetch information through the client's internal API for calculation on the currency calculator. Optimized solutions for SEO and handled the complexities of different tasks on the project.

Education

BSc. Computer Science
BSc. Computer Science
University of London
2021 - 2026 (5 years)