# marielise.dev > Portfolio of marielise, an anonymous software engineer and systems architect with 8+ years of experience. Ships SaaS products, publishes Apify actors, and maintains open-source libraries. Work is public; identity is private. Canonical site: https://marielise.dev/ ## About marielise is a pseudonymous builder. Documented track record: 3 SaaS products shipped, 20+ Apify actors published, 8+ years building software, 6 programming languages in active use. Operating principle: "Anonymous by choice. Competent by proof." - [Homepage](https://marielise.dev/): Single-page portfolio covering projects, services, about, and FAQ. - [About section](https://marielise.dev/#about): Background, philosophy, and stats. - [FAQ](https://marielise.dev/#faq): Services, technologies, hiring, and the anonymity rationale. ## Services Select projects only. Works with teams that value craftsmanship and technical depth. - [Websites](https://marielise.dev/#services): Custom design and development. Vanilla HTML/CSS/JS or modern frameworks. 100/100 Lighthouse scores. Sub-1s load times. SEO and accessibility built in. Mobile-first responsive. - [SaaS Applications](https://marielise.dev/#services): Full-stack TypeScript web apps built for scale. Vue, Node.js. Architecture and system design, backend APIs and databases, authentication and payments, deployment and monitoring. - [Automations & Scraping](https://marielise.dev/#services): Web scraping and data extraction, Apify actors and crawlers, workflow automation, API integrations, data processing pipelines. Targets 5-10 hours per week saved on manual tasks. ## Selected Projects - [Parafunnel](https://parafunnel.com/): SaaS dashboard for lead generation agencies to monitor all client funnels in one view. Sends instant alerts when conversions drop. Cuts daily monitoring time from 30 minutes to 30 seconds (98% reduction). - [ChillThat](https://chillthat.com/): AI-powered tool that transforms negative comments into constructive feedback. Helps users read criticism through a constructive lens. - Apify actors: 20+ published web-scraping and automation actors on the Apify platform (rendered live on the homepage projects grid). ## Tech Stack - Languages: TypeScript, JavaScript, Go, Rust, Python (5 of 6 languages in active use; sixth varies by project). - Frontend: Vue 3, Nuxt, vanilla HTML/CSS/JS. - Backend: Node.js, distributed systems, system architecture. - Tooling: Vite, Docker, Linux, IoT hardware. - Platforms: [Apify](https://apify.com/) (web scraping and automation actors). - Focus areas: full-stack development, web automation, performance optimization, distributed systems. ## Contact - Email: [hello@marielise.dev](mailto:hello@marielise.dev) - Twitter / X: [@marielise_dev](https://x.com/marielise_dev) - GitHub: [christellevs](https://github.com/christellevs) - Support: [Buy Me a Coffee](https://buymeacoffee.com/christellevs) - Canonical website: [marielise.dev](https://marielise.dev/) ## Etsy Sales Intelligence: Tool Pages Landing pages for the Etsy Sales Intelligence Apify actor (etsy-sales-estimator). Estimates hidden Etsy per-listing sales and revenue from public review signals, shop stats, and price-tier adjustments. $0.05 per listing, pay-per-event, no subscription. Callable from Claude, Cursor, and any MCP client via the Apify MCP server. - [Etsy Sales Estimator](https://marielise.dev/tools/etsy-sales-estimator/): Main product page for the Etsy Sales Intelligence Apify actor. Covers what data the actor returns (estimated units sold, revenue bands with confidence levels, trending and dormant flags, shop context), how the adaptive review-rate model works, pay-per-event pricing ($0.05/listing), MCP callable from Claude and Cursor, and FAQ. For sellers, researchers, and developers who need revenue data from public Etsy listings at scale without a subscription. - [How to Estimate Etsy Sales](https://marielise.dev/guides/how-to-estimate-etsy-sales/): Pillar guide on the methodology behind Etsy sales estimation. Explains what data Etsy exposes publicly (shop totals, listing review counts, badges, velocity) versus what it hides (per-listing sales counts). Covers the review-rate formula, price-tier adjustments, niche calibration, confidence bands, trending and dormant signals, and manual versus automated approaches. Includes a comparison table of tools and a full FAQ. For anyone researching Etsy niche opportunities or competitor revenue. ## YouTube Video Downloader — Tool Pages Landing pages for the YouTube Video Downloader Apify actor (youtube-video-downloader). Downloads YouTube videos and Shorts in MP4 (360p to 1080p) or MP3 format. Pay-per-event pricing billed per minute of video downloaded ($0.020/min at 360p to $0.040/min at 1080p, $0.010/min for MP3). No failed-download charges. Batch downloads supported. - [YouTube Video Downloader](https://marielise.dev/tools/youtube-video-downloader/): Main product page for the YouTube Video Downloader Apify actor. Covers MP4 and MP3 output formats, quality tiers (360p to 1080p), YouTube Shorts support, batch downloads, direct download links stored in Apify key-value store, pay-per-minute pricing table, residential proxy fallback option ($0.05/MB when triggered), and FAQ. For content creators, educators, podcasters, journalists, and researchers who need reliable programmatic YouTube video or audio downloads without browser extensions or local software. - [How to Download YouTube Videos](https://marielise.dev/guides/how-to-download-youtube-videos/): Pillar guide on downloading YouTube videos programmatically. Covers yt-dlp internals, client path hierarchy (android_vr, mweb, ios, web + PO token), proxy layers and economics, the 230 MB file size limit, running yt-dlp in cloud environments (cold starts, rate limits), and the managed API tradeoff. Includes Node.js integration examples and a full FAQ. For developers, content managers, and power users who want to automate YouTube downloads. ## eBay Sold Listings — Tool Pages Landing pages for the eBay Sold Listings Intelligence Apify actor (ebay-sold-listings-intelligence). Extracts real transaction prices from eBay completed listings with pricing analytics: recommended price, price range (10th-90th percentile), market velocity (average days to sell), demand level, condition breakdown (New vs Used), and auction vs Buy It Now comparison. Supports 8 eBay marketplaces. Pay-per-event pricing approximately $0.10 per 100 items. - [eBay Sold Listings Intelligence](https://marielise.dev/tools/ebay-sold-listings/): Main product page for the eBay Sold Listings Intelligence Apify actor. Covers real sold price extraction (not listing prices), recommended price calculation, price range analytics, market velocity scoring (very_fast to very_slow), condition-based price breakdown, listing type analysis, multi-marketplace support (US/UK/DE/FR/IT/ES/CA/AU), batch processing up to 200 items per run, CSV and Markdown report outputs, confidence scoring, and FAQ. For eBay resellers, estate sale operators, collectors, consignment shops, and arbitrage researchers who need data-driven pricing based on actual transactions. - [How to Find eBay Sold Listings](https://marielise.dev/guides/how-to-find-ebay-sold-listings/): Pillar guide on finding and using eBay sold listings data. Explains how to apply the sold listings filter, use direct URL parameters (LH_Sold=1, LH_Complete=1), what the data shows and what it does not, how to read prices correctly (sold vs asking, median vs mean, condition labels), assessing market velocity manually, international market research, and when manual research stops being practical. Full FAQ. For eBay resellers, estate sale operators, collectors, and anyone making pricing decisions based on eBay market data. ## Optional - [Sitemap](https://marielise.dev/sitemap.xml): XML sitemap for the site. - [robots.txt](https://marielise.dev/robots.txt): Crawler directives, including allow-list for major AI crawlers (GPTBot, ClaudeBot, PerplexityBot, OAI-SearchBot, Applebot-Extended, CCBot, Google-Extended). - [OG image](https://marielise.dev/og-image.png): Social preview card.