> Markdown version of [/jobs/ext/331871-software-developer](https://www.wearedevelopers.com/jobs/ext/331871-software-developer). Every page supports `.md` or `Accept: text/markdown`. Links point to the HTML versions so they work for humans too. Agent guide: [/agents.md](https://www.wearedevelopers.com/agents.md). --- # Software Developer - **Company:** Veriscope Digital - **Location:** UK (Remote available) - **Salary:** £31,200.0 - £62,400.0 - **Contract:** Permanent contract - **Skills:** HTML, JavaScript (Programming Language), Application Programming Interfaces (APIs), Artificial Intelligence, HTML5, Cascading Style Sheets (CSS), Github, Messaging Application Programming Interface, Next.js, Systems Integration, ReactJS, Prompt Engineering, Web Content, Stripe, Information Technology, Cloudflare, GPT, Software Version Control - **Published:** June 7, 2026 - **Apply:** https://uk.indeed.com/viewjob?jk=1c5cd81e9c0a438e ## About the Role Do you have experience in UI?, * Demonstrable experience building Chrome extensions using Manifest V3, including content scripts, background service workers, and the Chrome messaging API. * Strong proficiency in vanilla JavaScript, including asynchronous patterns, chrome.storage.sync, and browser extension APIs. * Hands-on experience with Cloudflare Workers and Wrangler, including KV namespace management and secret configuration. * Familiarity with the OpenAI Chat Completions API and prompt design for classification tasks. * Experience integrating Stripe, including checkout sessions, webhook verification (HMAC-SHA256), and subscription lifecycle events. * Solid understanding of HTML5 and CSS3 for extension popup and options UI work. * Version control with Git and GitHub is essential. * Experience with DOM traversal and content manipulation across diverse page structures, including React and Next.js sites, is a strong advantage. * Prior experience shipping a published browser extension is strongly preferred. * A Computer Science or related degree preferable but not compulsory. ## Description Content Sieve is an AI-powered Chrome extension (Manifest V3) that filters web content by topic across any website, using OpenAI's API via a Cloudflare Worker proxy to intelligently distinguish genuine topic matches from false positives. The extension is live on the Chrome Web Store with a working free/premium tier model and Stripe subscription billing already in place. We are looking for a developer to help extend its capabilities, improve filtering accuracy, and build toward a more polished product., * Develop, test, and deploy updates to a Manifest V3 Chrome extension using vanilla JavaScript, working across content scripts, background service workers, and the popup UI. * Improve and extend the core AI filtering logic, including the keyword-first gate and dual-model routing between GPT-4.1-nano (free tier) and GPT-4.1-mini (premium tier). * Maintain and enhance the Cloudflare Worker back end, including the /api/check-content, /api/validate-key, /api/checkout, and /api/stripe-webhook endpoints. * Work with Cloudflare KV namespaces for licence key storage and free-tier daily cap enforcement. * Extend or improve the Stripe integration, including checkout session creation, webhook handling, and licence key generation on successful payment. * Improve DOM traversal logic in the content script for more reliable card detection across deeply nested React and Next.js page structures. * Maintain and improve the popup UI, built in HTML, CSS, and vanilla JavaScript. * Manage session caching logic and client-side rate limiting (token bucket) to minimise unnecessary AI calls. * Use Git and GitHub for version control throughout. * Document architectural decisions and deployment steps clearly for ongoing reference. * Help build the Android and iOS version ## Related Videos - [The Resilience of the World Wide Web](https://www.wearedevelopers.com/videos/1281-the-resilience-of-the-world-wide-web) - [Extensionator - Rise of the Chromium](https://www.wearedevelopers.com/videos/119-extensionator-rise-of-the-chromium) - [ Evaluating AI models for code comprehension](https://www.wearedevelopers.com/videos/1462-evaluating-ai-models-for-code-comprehension) - [Explore new web features before everyone else](https://www.wearedevelopers.com/videos/316-explore-new-web-features-before-everyone-else) - [Can SVG be fast? 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