Mobile Engineer Flutter & Dart || Bitcoin and LIghting || Opensource Contributor.

Abuja_Nigeria
Hello everyone 👋 My name is Usman Umar Garba I’m a 3rd-year Computer Engineering student and a Mobile Engineer (Flutter), actively building cross-platform applications. I’m currently expanding into backend development with Python (APIs) and exploring Bitcoin &
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4 weeks ago, I started building Fastpay, a fintech mobile app, in public. I’ve worked on fintech applications for companies before, so the idea of building another fintech app wasn’t because I wanted to learn what a wallet, card, or transfer flow looks like. I wanted something I could put in my portfolio that actually shows how I approach building a complete fintech product, from the mobile interface to the backend systems behind it. So I started Fastpay from scratch. The first few days were mostly about getting the foundation right: setting up the Flutter application, authentication, OTP verification, PIN sign-in, and the Go + Gin + PostgreSQL backend. Then the project started becoming much more interesting. I began building the actual financial flows one by one, though I focused on internal wallet infrastructure and mocked external payments: sending and requesting money, deposits, QR payments, cards, transactions, currency exchange, IBAN and SWIFT transfers, phone top-ups, and scheduled transfers. And with every feature, I had to think beyond the screen. How should the API handle the transaction? What happens if a request is sent twice? What data should the backend store? How should the mobile app respond to different states? How should authentication and authorization be handled? At the same time, I paid a lot of attention to the UX. I wanted Fastpay to feel better to use, not just function correctly. I spent time simplifying flows, reducing unnecessary steps, improving how information is presented, and making different parts of the app feel consistent. That has probably been one of the most valuable parts of building Fastpay: taking the fintech patterns I’ve already experienced and rethinking how I would design and build them myself. I’ve also built the less visible parts of the product: analytics, notifications, security and privacy settings, device and session history, personal details, notification preferences, language settings and other account management flows. I’ve been sharing the process almost every day for the last 4 weeks, documenting how the product has evolved feature by feature. Fastpay is still a portfolio project, and I’m not building it with the intention of launching it as a fintech company. I’m building it to push my engineering skills, experiment with different approaches, and have a project that represents the kind of software I’m capable of building, both technically and from a UX perspective. I’m wrapping up the Fastpay build this week, and I’m looking forward to sharing the final result and everything that went into building it. I’m Ahiakwo John, a fullstack web and mobile app developer with over 4 years of experience, passionate about using technology and AI to build useful products. I’m open to collaboration and opportunities.
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Abraham (@abeeujah) is a developer based in Nigeria 🇳🇬, whose Bitcoin open-source journey began through @BitDevsKaduna. He built his knowledge through @ChaincodeLabs’ protocol development seminars, the @FreeRoutingAf Kaduna Lightning Developer Bootcamp, and Bitcoin Core Principles by @libdesatoshi. He also completed the 2026 BOSS Challenge and was featured by @btrust_builders as one of eleven African participants whose journeys stood out. With the starter grant, Abraham will focus on testing, protocol libraries, and developer tooling across rust-bitcoin and rust-lightning, strengthening the building blocks developers use for Bitcoin and Lightning applications.
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The frontend shell is now taking shape. Next up: connecting it to the Rust node and making the full protocol flow real. ⚡🦀 @bitshala_org @tech_lateef @Muhamma90584326 #lighting #bitcoin #opensource #Rust @devfolio
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Been heads down building Infernos 🔥 We're building permissionless open-model inference paid in sats. Ask → 402 → Pay → Prove → Unlock → Infer Lightning payments, L402 authorization, capability-based access, bounded session budgets, and privacy by default.
Exactly payment isn’t just billing here , it’s the authorization primitive. pay → preimage → prove → unlock the next step. That’s what makes L402 interesting for machine-to-machine workflows beyond just inference.
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Been heads down building Infernos 🔥 We're building permissionless open-model inference paid in sats. Ask → 402 → Pay → Prove → Unlock → Infer Lightning payments, L402 authorization, capability-based access, bounded session budgets, and privacy by default.
Exactly payment isn’t just billing here , it’s the authorization primitive. pay → preimage → prove → unlock the next step. That’s what makes L402 interesting for machine-to-machine workflows beyond just inference.
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The frontend shell is now taking shape. Next up: connecting it to the Rust node and making the full protocol flow real. ⚡🦀 @bitshala_org @tech_lateef @Muhamma90584326 #lighting #bitcoin #opensource #Rust @devfolio
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be there.
Join us for the first Bitcoin Developers Meetup in Zaria, a space for developers, builders, and Bitcoin enthusiasts to connect, learn, and explore the technology powering a new financial and digital frontier. Register here: luma.com/zc84r9wn #Bitcoin #BitDevsZaria
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We’re excited to announce the Q3 2026 Btrust developer grant recipients. 🚀 Ten Bitcoin open-source developers are receiving support: five starter grant recipients and five long-term open-source cohort members. This quarter also marks an important first: Btrust developer grants are going directly to developers outside Africa. Through our recent expansion of long-term grants across the Global Majority, we’re now supporting developers in Brazil 🇧🇷 and India 🇮🇳. Their work, alongside that of recipients in Nigeria 🇳🇬 and Kenya 🇰🇪, spans @bitcoincoreorg, mining ⛏️ infrastructure, Lightning⚡, wallet libraries, and privacy-preserving payments. Meet the recipients and learn about their work:
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100 days of code to go 🥳 Consistency.
What did I work on Fastpay today? Today is Day 265 of 365 Days of Code. Today, I worked on the Analytics screen, giving users a better view of their income and spending activity. 👉 Added Expenses and Income analytics with totals, transaction counts, category counts, and tag counts 👉 Added Categories and Tags breakdowns with amounts and percentages 👉 Added card filtering so users can select which cards to include in their analytics 👉 Added date range filtering with a calendar selector 👉 Connected the screen to the GET /analytics endpoint so the data is loaded dynamically Users can now filter their analytics by cards and date range, making it easier to understand where their money is going and how their finances are changing over time.
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Exactly payment isn’t just billing here , it’s the authorization primitive. pay → preimage → prove → unlock the next step. That’s what makes L402 interesting for machine-to-machine workflows beyond just inference.
Replying to @dev_useee
Pay → preimage → auth is the whole point of L402. Same shape for human loops: settle a miss or a claim over Lightning, prove it, then unlock the next step. No session cookie pretending to be money.
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Day 13 — Infernos ⚡️ Big milestone today. We shipped the operator + caller CLI and got the full cross-process L402 flow working: 402 → pay → preimage → auth → inference Also added: Node lifecycle management Graceful shutdown Session budgets Cryptographic payment verification
Day 12 of building Infernos ⚡️Today was about making the caller side of Infernos more real. We're building a client that can: ⚡️ Request an inference session ⚡️ Handle the L402 payment challenge ⚡️ Track a spending budget ⚡️ Authenticate requests without API keys
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Mock Lightning settlement The node and caller now work as separate processes. Infernos is becoming a real system. 🔥 @bitshala_org @tech_lateef @devfolio #bitcoin #lighting #opensource
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Day 12 of building Infernos ⚡️Today was about making the caller side of Infernos more real. We're building a client that can: ⚡️ Request an inference session ⚡️ Handle the L402 payment challenge ⚡️ Track a spending budget ⚡️ Authenticate requests without API keys
Day 11 of building Infernos ⚡️ Today we pushed deeper into the machine-money layer. Infernos is becoming more than just an inference API — we're building a way for machines and agents to pay for AI compute using sats. Today's focus:
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⚡️ Talk to an open-weight model through the Infernos nodeThe interesting part isn't just paying for an API.I t's making AI inference something a machine can autonomously pay for. Rust + Lightning + open models. Run the model. Set the price. Let machines pay. Day 12/29 🚀
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Doing what I love most, talking, teaching about bitcoin. Thank you for the opportunity to be able to mentor others just as you have also invested in me... @btrust_builders @btrustteam @the_buidl
From learning to contributing. ⚡ Sessions 15 & 16 of Rust for Bitcoin 2.0 focused on Open Source Development & Bitcoin Core Contribution, giving participants practical experience with the workflows behind contributing to open source Bitcoin projects. With @0xGideonBature guiding the sessions, participants explored Git workflows, writing and reviewing PRs, reading BIPs, Bitcoin Core Review Club methodology, issue triaging, and open source etiquette. The learning moved straight into practice as participants forked projects, reviewed PRs, opened issues, made project changes, and prepared and submitted their own PRs while following proper GitHub workflows. Two sessions focused on turning development skills into practical open source contributions, giving participants a stronger foundation for collaborating, reviewing code, managing issues, and contributing to Bitcoin projects. #TheBuidlGrid #RustForBitcoin
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Day 11 of building Infernos ⚡️ Today we pushed deeper into the machine-money layer. Infernos is becoming more than just an inference API — we're building a way for machines and agents to pay for AI compute using sats. Today's focus:
Replying to @dev_useee
🧾 Session-based L402 credentials 💰 Atomic client-side spending limits 🤖 OpenAI-compatible client interface 🔄 Client ↔ Infernos Node end-to-end integration 🧪 New budget, payment, builder & integration tests
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🔹 Session-based L402 authentication 🔹 Budget-aware inference 🔹 Payment-aware client architecture 🔹 Safer session lifecycle handling 🔹 Preparing streaming support The goal is simple: Run the model. Set the price. Let machines pay. Still building. Still testing. ⚡️
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Infernos — Permissionless Open-Model Inference Paid in Sats. #BOSSBattle2026 #Bitcoin #Lightning @bitshala_org @tech_lateef @Muhamma90584326
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