Jasan Hernandez · Software Engineer · 7+ years
Frontend foundation -> full-stack systems -> serverless APIs, data workflows & AI automation.
$ whoami --verbose ROLE Software Engineer BASE Puebla, MX (UTC-6) RUNTIME 7+ years building software TRAJECTORY frontend foundation -> full-stack -> serverless / data / AI automation SIGNAL product-minded engineer who owns systems end-to-end: interface, API, data model, runtime constraints, delivery STATUS system online - open to complex problemsI started by building interfaces, and frontend is still one of my strongest layers. But I moved quickly into full-stack work because I like understanding the whole machine: UI, API contracts, data models, infrastructure, algorithms and failure modes.
Most engineers pick a layer. I work across the seams: where UI meets data, where APIs meet runtime limits, where business workflows meet automation.
My strongest work happens in three intersections:
| Intersection | What it looks like in practice |
|---|---|
| Interface x Data | Analytical dashboards, time-series visualization, endpoints shaped for charts, not just CRUD |
| Backend x Edge constraints | Serverless APIs on Cloudflare Workers, where cold starts, bundle size and runtime APIs actually matter |
| Product x Automation | AI-assisted pipelines that scrape, normalize, decide and notify, replacing manual workflows entirely |
I care less about the framework and more about the shape of the system: boundaries, contracts, data flow and failure modes.
$ system.map --domains [FRONTEND_ARCHITECTURE] React · Next.js · SSR/SSG · microfrontends · TurboRepo design systems · Storybook · performance budgets · custom build tooling [SERVERLESS_AND_EDGE] Cloudflare Workers · REST · GraphQL · NestJS Zod validation · caching (Cache API / Hyperdrive) · WASM adaptation [REALTIME_SYSTEMS] WebSockets · Socket.io · multi-operator state · comments/replies nested data models · browser APIs · event-driven interfaces [DATA_ENGINEERING] PostgreSQL · advanced SQL (CTEs, window functions, LAG/PARTITION BY) Kysely · ETL pipelines · scraping · time-series analytics [AI_AND_AUTOMATION] n8n · OpenAI · embeddings · Telegram API · Notion API dynamic PDF generation (React PDF) · workflow orchestration [MOBILE_ENGINEERING] Flutter/Dart · React Native/Expo · clean architecture secure storage · biometric auth · camera/QR flows [SYSTEMS_THINKING] clean architecture · domain/application/infrastructure layers real-time interfaces · multi-user state · MediaDevices APIs [OOP_AND_ALGORITHMS] Java · PHP/Laravel foundations · object-oriented programming recursion · data structures · hard programming challenges [INFRA_AND_DELIVERY] Linux servers · PM2 · Docker · CI/CD · Vercel · GitHub/GitLab environment config · process monitoring · production debuggingTechnologies I've shipped and maintained in real products, not tutorial exposure.
Languages & Core
Frontend & Product UI
Backend, APIs & Edge
Data & Automation
Build, Infra & Delivery
Integrations & Product Services
Mobile
Computer Science & Programming Foundations
Technologies I've used in research, prototypes and side systems. Listed separately on purpose: I keep a clear line between production experience and exploration.
$ system.map --layer=exploratory LANGUAGES Python · Rust · C++ · Java · PHP/Laravel WEB_DEEP WebAssembly · Service Workers · Workbox · Three.js · Chart.js · Canvas API CS_THEORY finite automata · parsers · regular expressions · compiler fundamentals recursion · object-oriented design · data structures DATA/ML PyTorch · sequence models · feature engineering · model evaluation QUANT Binance Futures · algorithmic trading research · risk guards · signal audits INFRA Linux servers · PM2 · Docker · SQLite · CI/CD · process monitoringThe kinds of problems I've worked through, a better signal than job titles.
| Problem | How I've approached it |
|---|---|
| Raw operational data -> business metrics | ETL normalization of meter data, PostgreSQL time-series queries (CTEs, LAG, PARTITION BY), tariff-period aggregation, delta computation from cumulative readings |
| Backend logic under edge constraints | Cloudflare Workers with TypeScript, WASM adaptation of incompatible libs (yoga-layout), strategic caching (Cache API, Hyperdrive), latency reduction on critical endpoints |
| Type-unsafe SQL -> typed queries | Migrating complex native SQL to Kysely with exact parity: aliasing discipline, analytical functions, compile-time safety |
| Data that needs to be seen | Endpoints shaped for visualization: consumption, demand and cost structures optimized for charting layers |
| High-friction workflows -> automation | Scraping official portals (dynamic ASP.NET tokens, session handling), structured persistence, OpenAI-assisted parsing, Telegram alerts, dynamic CV-to-PDF rendering |
| Nested social interactions | Recursive comment/reply models, parent-child rendering, optimistic UI states, moderation-friendly data structures and pagination boundaries |
| A programming language for children | Vanilla JavaScript, prototypes, regex tokenizer, DFA validation, Spanish function syntax, parameter parsing, coordinate-based drawing and Canvas rendering for geometric figures |
| Real-time, multi-user interfaces | React + MediaDevices APIs, audio/device control, multi-user session state, tight QA feedback loops |
| Realtime business messaging | WebSocket synchronization, multi-operator sessions, QR authentication, broadcast flows, role-based access and event-driven state updates |
| Frontend codebases that must scale | Microfrontends with TurboRepo, component contracts, Storybook-driven design systems, SSR/SSG strategies |
| Custom build constraints | Webpack/Babel/esbuild tuning, module resolution, bundle splitting, environment-specific builds and legacy dependency adaptation |
| Self-managed runtime infrastructure | Linux server provisioning, PM2 process supervision, memory pressure debugging, log-based diagnosis and production process recovery |
| Trading systems where win rate lies | Python inference services, TypeScript execution bots, Binance Futures signals, risk guards, PnL audits, MFE/MAE analysis and random-baseline validation |
| Object-oriented domain modeling | Java/PHP foundations, encapsulation, inheritance, polymorphism, class contracts, domain entities and maintainable service boundaries |
| Auth, billing and premium content | Google OAuth, JWT/cookies, protected routes, Stripe subscriptions, Firebase-backed state and third-party API orchestration |
| Mobile flows where trust matters | Fintech apps in Flutter: encrypted storage, biometric auth, QR/camera via platform channels, clean architecture layering |
Where theory meets product. Small systems built to understand how things work underneath.
$ ls ~/research automata-lang/ Educational programming language in Spanish for kids. Built in vanilla JavaScript using prototypes. Children executed Spanish functions by passing a figure name, drawing attributes and coordinates. A regex tokenizer and DFA/transition-matrix validator checked the language before rendering geometric figures on Canvas. ml-trading/ Algorithmic trading research in Python: feature engineering, model evaluation, predictive experiments on market data, Binance Futures signals, risk guards, live/research audit loops, MFE/MAE and expectancy analysis. aegis-turbo/ Research ecosystem around a Python inference engine and TypeScript execution bot. Includes snapshot refreshers, PM2 process orchestration, model manifests, signal logs, score calibration, random baselines and risk-first strategy evaluation. systems-langs/ Rust, C++ and Java explorations: memory models, performance characteristics, and what they teach about the JS/TS runtimes I use daily. oop-foundations/ Java and PHP/Laravel foundations: classes, inheritance, polymorphism, encapsulation, recursive problems, data structures and algorithmic exercises from online judges. parsers-and-formal/ Parsers, formal languages, regular expressions: the fundamentals behind every validation engine I've ever shipped.$ grep --skills ./jasan-profile SENIOR_FRONTEND React, Next.js, TypeScript, SSR, design systems, Storybook, microfrontends, performance, frontend architecture FULL_STACK Node.js, NestJS, Express, GraphQL, REST APIs, PostgreSQL, MySQL, Firebase, Supabase, PHP, Laravel, clean architecture SERVERLESS_DATA Cloudflare Workers, edge runtime, Kysely, advanced SQL, CTEs, window functions, ETL, caching, PDF reports AUTOMATION_AI OpenAI, embeddings, n8n, scraping, Telegram bots, Notion API, workflow orchestration, dynamic documents REALTIME_MOBILE WebSockets, Socket.io, MediaDevices, Flutter, React Native, Expo, secure storage, biometrics, QR/camera flows RESEARCH_SYSTEMS Python, Rust, C++, Java, PHP, OOP, automata, parsers, recursion, algorithms, ML experiments, algorithmic trading, model evaluation, Linux infrastructure, DockerOpen to collaboration on complex systems, senior engineering roles, and products where the hard part is the interesting part.
$ contact --channels PORTFOLIO https://jasanhdz.vercel.app LINKEDIN https://linkedin.com/in/jasanhdz EMAIL jasan814@gmail.com GITHUB https://github.com/JasanHdz RESPONSE_TIME usually < 24h[ SYSTEM ONLINE - BUILDING ]