Jesús Gulfo

Every Android build carries one: the flags that decide what a ROM claims to be. The wrong value here and the phone is a paperweight.

ro.build.version.release=1.5
ro.build.version.codename=Cupcake
ro.product.model=Xperia X10 Mini Pro
ro.bricks.logged=a few
ro.bricks.recovered=most of them

Android gave a phone one density for everything. Per-App DPI let each application have its own, so a cramped app could breathe and a sparse one could fit more.

Built on Per-App DPI: an app could be told it was running on a tablet and would bring out the tablet layout it already shipped.

Halo put chat-head style multitasking on every app, not just messaging. Per-App Color tinted the system around whatever was in front. Both were adopted or imitated across the modding scene.

All of it in public, on the forums: release threads, bug reports at one in the morning, and the documentation and guides that let a growing contributor base work without asking first. 3,800+ posts, 16K+ reactions.

A motion-based notification manager: pick the phone up, see what arrived, act on it, without waking the whole device. About 4.1 stars on Google Play until it came down in early 2016.

Covered by Android Police, Android Authority, Android Headlines and others for bringing Active Display style notifications to any phone on Android 4.4 or later.

The other indie apps from the same years. Small utilities, kept light.

Patching AOSP for fun means a bad build costs you an evening. For a shipping device it means review, compatibility and an over-the-air train that cannot be called back once it leaves.

Prototyping features on the latest Android APIs and SDKs, then hardening them through OnePlus's fast international growth.

Graduated mid-OnePlus with a thesis on an autonomous LEGO EV3 robot: vision-based control on a Raspberry Pi and a phone app to watch what it saw. In 2022 it became a paper I co-authored in Machines (MDPI).

Schemas written from product requirements, then the data analysis to prove the numbers were accurate and worth acting on, with product, engineering and data science.

Requirements into technical specs, feature planning, and code reviews meant to teach as much as catch. Dec 2018 to Apr 2019.

Casting for Fire TV and Android TV, as sender and receiver. 57% of Roku casts and 23% of Fire TV casts drove app installs. Apr to Aug 2019.

New features for an enterprise point of sale used by Live Nation and major league venues, with the backend integration over gRPC.

Architecture diagrams, integration specifications and technical documentation, kept current for onboarding and the long run.

Led discovery and planning inside Roundfeather's user-centred process, turning business goals and technical constraints into an execution roadmap.

Managed the mobile and web teams through two native apps and a responsive web app sharing one experience.

Over a million users within three months of launch, carrying about 32% of the transactions it touched.

Worked with regional engineering and stakeholder teams so every brand got a consistent implementation and an on-brand experience.

Development and deployment of Colsubsidio's Piscilago app, used in person by thousands of visitors a year.

The architectural foundation of Homecenter Colombia's new app for 1M+ monthly users, plus location-aware recommendations and checkout, with load times cut by about 30%.

Android, iOS, backend, web, QA and automation engineers, working with business, product, design and marketing.

Native apps and backend services with authentication, CRM, CMS and marketing integrations, designed to grow to 50 resorts and 8,000+ rooms.

Retrieval that holds up when the content moves, the integrations that put it in front of people, and deciding what an assistant should and should not do.

A C++/CUDA engine: dense layers and KV cache on the GPU, routed experts in system RAM streamed a layer at a time, so a model far larger than any single card runs on one machine.

• One .basalt file per model, converted out of GGUF without requantizing
• Speculative decoding, quantized KV cache, batch slots
• Speaks the OpenAI and Anthropic APIs
• Packs published with perplexity and KL divergence

Part of Quecto. Puts an OpenAI-compatible model server on the internet without one shared password: expiring keys, per-key limits, quotas and metadata-only logs. One binary, one SQLite file; prompts are never stored.

The other half of Quecto: a coding agent for a model you host yourself. Named agents, plan and execute modes, permissions per call, and a session scoped to one folder.

Pace, reliability and the outsider-win rate from real results, a Monte Carlo over the rest of the season, and a Wayback mode for any year since 2020. Frequently wrong.

Character sheets that derive everything from six scores, and a DM view that pushes initiative and combat onto every player's sheet.