I'm Simon Betton, a principal software engineer in Auckland with over 19 years of experience across backend and frontend. I design architecture that stays simple as products and teams grow, focusing on technical strategy, clear system design, and the long-term decisions that keep code maintainable.

Such is a payments app for iOS and Android that moves real money, with a merchant side for invoices, quick charges, and hosted payment links. It is non-custodial: keys are generated, held, and used to sign on the device, so the backend never sees a secret, and every transfer it authorises is irreversible. As founding engineer and principal, I set the React Native architecture and the conventions 16 contributors across several teams now work to. I led the team to deliver quickly using shared coding styles and patterns, with complexity and coverage findings informing peer review.

OneTwo builds the enterprise automation ANZ Australia uses to process home loan applications. I was Technical Lead of one of four engineering teams, and domain lead and architect for HLQ, the workflow platform. HLQ is the orchestration engine that moves each loan application through its stages (driven by a versioned, human-readable rules language), with integrations with the bank's lending systems, and the human-in-the-loop interface where staff complete user tasks. Every step and action is timed and auditable, and automatic failures fall back to a human task.

GetSetUp is a live and on-demand classroom for 4+ million older adults. As Lead Software Engineer and technical lead on the platform rewrite I co-designed with the platform team the GraphQL backend-for-frontend and the Presentation API that built every page's layout and section shapes server-side, so web, mobile, and the live-class lobby rendered the same page from one contract and editorial changes needed no frontend release. Across a microservice platform on EKS I was code owner for the content layer, class sessions with Zoom, the admin app, partner attribution, the event pipeline into Amplitude and Zendesk, and GetSetUp Embedded for partners like AOL.

Plant & Food Research is a state-owned New Zealand research institute working on agriculture and food systems. As lead developer at DDB I designed and built its public platform on Contentful, with a highly customisable content model carrying a large volume of research content. Algolia served that content fast with near-unlimited filtering, so visitors could cut across the whole catalogue without waiting on the CMS.

GeminAI Rising is an online learning game for grades 7-9, built by DDB for Alberta Health Services to teach problem-solving and coping skills. It arrived about 90% complete and unstable. As Technical Lead I rebuilt the server and real-time session layer from scratch, kept the React screens worth keeping, and shipped a version that holds a full lesson on flaky school networks. It still runs in Alberta classrooms today.

New Zealand Trade and Enterprise is the government agency that helps New Zealand businesses grow internationally. In 2020 I led the engineering at DDB on its investment platform, built on Next.js, TypeScript, and Contentful, which connects New Zealand businesses and Māori enterprises with partners and capital and presents New Zealand opportunities to overseas investors.

Re:scam kept scammers occupied by replying to their emails with approved, human-written lines. As Tech Lead at DDB, I was the sole engineer on NetSafe's original bot, launched in November 2017: IBM Watson classified incoming messages and selected replies from the copywriters' library. In 2019 I led a separate rebuild for licensing to Westpac Australia, using Google Cloud for classification and sensitive-data detection, and Algolia to retrieve replies. That rebuild was completed, penetration tested, and reviewed, but never launched.

Fight for Territory was an installation across Auckland Airport's domestic and international terminals for the 2017 Lions tour. Stand in front of a digital display and your face claims a screen for the All Blacks or the Lions. As Tech Lead at DDB I built the whole system, from browser-based face detection on a Raspberry Pi behind each of 65 screens to the 4K signage, the real-time state API between them, and the ops dashboard, with a failover mode so a dropped camera or network never left a frozen screen.

McDonald's New Zealand offers free in-store Wi-Fi nationwide on Vodafone's network. 30 minutes a day for guests, unlimited for mymacca's members. At DDB I built the captive portal that authenticated every guest and member and handed them to Vodafone, then rebuilt it against the new mymacca's account platform during the migration without interrupting access in any store.

Command the Unsullied was a Game of Thrones campaign for Sky, in partnership with Twitter. Thousands of Unsullied Army accounts answered #CommandTheUnsullied in real time. At DDB I built the platform behind it, a dashboard on Twitter's Streaming API that let the team craft replies and broadcast thousands of messages, retweets, and follows as the Unsullied army while the conversation was still moving.

Buzzdial was a second-screen platform that let broadcasters measure live audience sentiment while a show was on air. In 2014, before serverless and before infrastructure as code was common, two engineers had to take hundreds of thousands of concurrent viewers arriving within minutes of a broadcast. We shipped the first stage in four weeks. I owned the client interfaces and co-built the API, per-second sentiment pipeline, and auto-scaling AWS platform with the other engineer. It held 99.99% availability under 400 milliseconds for Seven, ITV, and the All Blacks.

TVNZ OnDemand was New Zealand's first on-demand streaming app for phones and tablets, released in 2013 on Brightcove App Cloud. Devices had a fraction of today's memory, WebKit had no JIT, and React Native did not exist. As sole developer I owned the client-side architecture for the iPhone and iPad apps, working directly with Brightcove on their video technology, and got a full streaming catalogue running smoothly inside those limits. Each app reached #1 on its store chart and won multiple Best Awards.

OnlyDoge is an open-source Ðogecoin block explorer and analytics platform with a tool-using AI analyst, built alone on a custom indexer and a ClickHouse warehouse. The chat runs a bounded tool loop. Eight read-only tools, hard step and time ceilings, and read-only access to chain data for grounding its answers. The model composes SQL for aggregate questions and the platform validates the AST before anything runs, and requests matching nine financial-advice phrasing patterns are refused in code before a model call.

KiwiCV is a free service that turns the CVs migrants already have into ones written for New Zealand employers. I built it alone as a nine-stage durable pipeline on Inngest. OCR and multimodal extraction, a human step where the customer confirms their career facts, then rewriting through a gateway with a three-vendor fallback chain and structured output as the contract at every boundary. A separate audit model checks the rewrite against the confirmed facts. The pipeline blocks saving if that audit still flags unresolved claims after two repair rounds.