Mohad J.

If you built your app with Lovable, Bolt, v0 or Cursor and it works, but you're not sure it's safe to put real customers and real payments on it, this is the kind of work I do. I'm Mohad, a full stack engineer. I've been building and fixing web apps since 2019, mostly on React, Next.js, Node.js, PostgreSQL and Supabase. The problems I get called in for are the same ones almost every time: Supabase tables with Row Level Security switched off, so one customer can read another customer's data. Login that works in the preview and breaks on the real domain. Stripe webhooks that fail quietly or run twice, so someone pays and never gets access, or gets charged twice. Builds that fail on Vercel the night before launch. None of that means starting over. I keep what already works, fix what is actually broken, and show you the proof. 𝗪𝗛𝗔𝗧 𝗜 𝗖𝗔𝗡 𝗗𝗢 𝗙𝗢𝗥 𝗬𝗢𝗨 Supabase security. Row Level Security policies on every table, storage rules that don't let strangers read uploads, auth that works on your custom domain, proper separation between admins and normal users, and no secret keys sitting in the browser bundle. Stripe billing that stays correct. Checkout, subscriptions, upgrades, cancellations, refunds and failed payments, all decided on the server, with webhook signature checks and idempotent processing so your database always matches what Stripe says. Next.js in production. Separate development and production environments, clean Vercel deploys, monitoring and backups, and performance work. For one US SaaS client I rebuilt their Stripe webhook handling and cut the JavaScript bundle from 10.5 MB to 135 KB in the same project. AI features that behave. OpenAI, Claude or Gemini features with proper error handling, rate limits and cost controls, so they don't surprise you with a bill or a broken screen. 𝗛𝗢𝗪 𝗪𝗘 𝗦𝗧𝗔𝗥𝗧 Most clients start with a Launch Readiness Audit. Over three business days I go through your Supabase project, your auth flow and your Stripe setup and check 25 specific things. You get a report ranked by severity, the actual test output, a short video walking through what I found, and a fixed quote for the fixes. If everything is already fine, I'll tell you that too, and you only pay for the audit. After that, fixes are fixed price and delivered as tested code in your own repository, with a plain English note on what changed and why. If you'd like someone keeping an eye on billing, access and errors after launch, I offer a monthly retainer for exactly that. 𝗛𝗢𝗪 𝗜 𝗪𝗢𝗥𝗞 I write the scope down before I touch code. I work on staging first and use Stripe test mode and test clocks before anything goes near live money. I never ask for your live secret keys; a team invite to Supabase and Stripe test access is all I need. I reply within four hours on working days and keep overlap with US mornings and UK and EU afternoons. 𝗔 𝗕𝗜𝗧 𝗔𝗕𝗢𝗨𝗧 𝗠𝗘 Every job on this profile is rated five stars, and the reviews say the same three things: I'm fast, the code doesn't come back buggy, and I understand what you want without needing every detail spelled out. Outside Upwork I built the EV charging app for EVC Point in Nigeria, rebuilt the client portal and hotel website for ARO Management & Technologies in the UK, and shipped Talent Source and Wish Genie through my studio, DevFlips, where I lead product and engineering. Their testimonials are on this profile too. I hold a BS in Computer Science as a gold medalist and run a registered software company in Pakistan, so you're working with a real business, not a throwaway account. If your app has users or a launch date and something about security or billing is keeping you up at night, send me the repository or your Supabase project. I'll tell you in one call whether you need an audit, a fix, or nothing at all.