Mario Hernandez
Python Developer
16+ years exp
2+ projects
Bash
SQL
Node JS
Python
Go
JavaScript
TypeScript
Active 1 day ago
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Overview
Technical skills
Timeline
Roles
Overview
Frontend UI engineer (middle) focused on admin dashboards and design-token-driven styling. The strongest proven skill is building consistent, theme-driven UI systems and styles as shown by the Tailwind configuration and comprehensive CSS modules (tailwind.config.ts and src/css/style.css). The work lacks evidence of advanced frontend systems engineering such as measured performance tuning, request-cancellation/optimistic-update discipline, or comprehensive a11y testing in public code.
Technical skills
Bash
SQL
Node JS• Middle
Python• Senior • 16y+
Go• Senior • 13y+ • 2 projects
JavaScript• Junior
TypeScript• Middle
Node JS
Axios
Bcrypt
Dotenv
Python
Gunicorn• 16y+
FastAPI• 8y+
Databases
MongoDB
MySQL• 16y+
PostgreSQL• 16y+
Redis• 16y+
Frontend
React.js
Next.js
Tailwind CSS
Redux Toolkit
Chakra UI
DevOps
Configuration Management
Git
Google GKE
Kubernetes
WebRTC
WebSockets
CI/CD• 16y+
GCP• 16y+
Rest API• 16y+
Docker• 13y+
Docker Compose• 12y+
Timeline
Senior Python Backend Engineer
•
Senior
Amaris
•
Full-Time
Developed backend services in Python using FastAPI and exposed REST APIs for internal and third-party integrations. Built a modular microservice architecture separating application, domain, persistence, and integration layers for maintainability. Implemented data-access components with PostgreSQL, Redis, and MySQL and supported containerized deployments and CI/CD automation using Docker, Docker Compose, and deployment pipelines.
Python
FastAPI
Rest API
Gunicorn
PostgreSQL
Redis
MySQL
Docker
Docker Compose
CI/CD
GCP
Python Back-End Developer
•
Middle
KeenEthics
•
Full-Time
Implemented server-side functionality in Python, including authentication flows, API endpoints, and integrations for web applications. Built and maintained REST APIs with consistent validation, response structures, and exception handling. Designed relational data models for PostgreSQL and MySQL, added Redis-based caching and temporary state handling, and packaged services with Docker while supporting CI/CD automation.
Python
Rest API
PostgreSQL
MySQL
Redis
Docker
CI/CD
Python Software Engineer
•
Middle
Seedium
•
Full-Time
Built backend applications and REST services in Python, including business logic, validation, and external system integrations. Implemented microservice-aligned APIs with consistent request validation, response formatting, and authentication-oriented error handling. Created persistence and caching layers using PostgreSQL, MySQL, and Redis and supported containerized development and CI/CD workflows.
Python
Rest API
PostgreSQL
MySQL
Redis
Docker
Docker Compose
CI/CD
Senior Python Developer / Lead Backend Engineer
•
Lead
SEROKELL
•
Full-Time
Led backend development for cloud voice and communication services using Python with FastAPI and Gunicorn. Designed distributed microservices for real-time conferencing, voice automation, transcription, and multilingual workflows via REST and event-driven interfaces. Implemented real-time call session and signaling components using SIP, WebRTC, and WebSockets, and managed persistence and caching with PostgreSQL, Redis, and MySQL.
Python
FastAPI
Gunicorn
Rest API
PostgreSQL
Redis
MySQL
Docker
Docker Compose
CI/CD
GCP
Google GKE
Kubernetes
WebRTC
WebSockets
Middle Backend Developer
Confidence: Medium API Engineer
Full‑stack API engineer (early career, middle tier) focused on Node.js-backed web apps and small ETL/data-migration scripts. The strongest proven skill is implementing authentication and user flows in Express with bcrypt and JWT as shown in Food-Delivery/Backend/controllers/user-controller.js. There is little evidence of production-grade resilience, schema migration history, performance tuning or automated tests in public code.
API Design
3/10
How well APIs are designed
Basic REST API patterns and JWT-based auth are implemented, but there is no versioning, no idempotency keys, inconsistent error contracts and limited input validation at boundaries.
Evidence
Food-Delivery/Backend/controllers/user-controller.js: Register and Login with bcrypt and jwt issuing accessToken
Food-Delivery/Backend/routes/routes.js: authenticateToken signature present
Data Layer & Database
2/10
Working with databases
Data layer work exists (MySQL ETL script and Mongo usage) but there is no migration history, no transaction management, no batching for bulk imports and limited attention to isolation or tuned queries.
Evidence
Excel-To-MySQL/index.js: Excel -> MySQL ETL using connection.query in a loop without transactions or batching
Food-Delivery/Backend/package.json: mongoose listed (MongoDB usage implied) and controllers reference model access
Scalability & Performance
1/10
Handling load and speed
Almost no scalability or performance engineering: no caching strategy, no queueing or async worker patterns, and no connection pooling or measured optimization artifacts.
Evidence
Healthier-Pets-FrontEnd/src/services/charts.services.ts: artificial setTimeout delays (demo/fake data patterns)
Excel-To-MySQL/index.js: single mysql connection + per-row inserts, no batching/pooling
System Architecture
2/10
Overall system structure
Standard single-repo separation between frontend and backend and use of Redux/Next.js, but architecture looks scaffold/boilerplate-driven rather than demonstrating deliberate service decomposition or config/secret management patterns.
Evidence
Healthier-Pets-FrontEnd/tailwind.config.ts: extended UI theming showing frontend customization
Food-Delivery/Frontend/src/Redux/*: Redux action/reducer structure demonstrating frontend-state decisions
Security & Auth
3/10
Protecting data and access
Basic auth and credential handling present (bcrypt, JWT, dotenv), but missing token lifecycle controls (expiry/refresh/revocation), rate limiting, and stronger input sanitization across the board.
Evidence
Food-Delivery/Backend/controllers/user-controller.js: bcrypt password hashing and jwt.sign with SECRET_KEY_TO_ACCESS from env
Excel-To-MySQL/index.js: dotenv used for DB credentials (env-based secret loading)
Reliability & Observability
1/10
Stability and monitoring
Minimal reliability and observability: occasional try/catch, console logs and no retry/backoff, jitter, structured logging, metrics or graceful shutdown patterns.
Evidence
Food-Delivery/Backend/controllers/user-controller.js: try/catch around register/login with basic error responses
Excel-To-MySQL/index.js: console.log on success/failure; no retry or timeout handling for DB operations
Expertise
Node.js• Middle
Microservices & API Architecture• Junior
Databases & Vector Storage• Junior
Industries
Food & Beverages• Middle
Technologies
Node JS• Middle
MySQL• 16y+
MongoDB
Bcrypt
Axios
Dotenv
Git• mentioned only
Recommendations
- Extend existing Node.js services into production-hardened APIs: add token expiry/refresh, explicit error contracts, input validation, and unit/integration tests for controllers and auth flows.
- Improve data-layer robustness: add transactional inserts or batching for the Excel-to-MySQL migration, use connection pooling, and track schema changes with a migration history.
- Introduce basic observability and reliability patterns: structured logging (correlation ids), timeouts on DB/HTTP calls, and simple retry/backoff where appropriate.
Repositories
The developer's experience in this domain has been verified based on AI analysis of the following repositories:
Middle Frontend Developer
Confidence: Medium UI Engineer
Frontend UI engineer (middle) focused on admin dashboards and design-token-driven styling. The strongest proven skill is building consistent, theme-driven UI systems and styles as shown by the Tailwind configuration and comprehensive CSS modules (tailwind.config.ts and src/css/style.css). The work lacks evidence of advanced frontend systems engineering such as measured performance tuning, request-cancellation/optimistic-update discipline, or comprehensive a11y testing in public code.
UI Component Architecture
4/10
How interface parts are built
Component and CSS structure shows deliberate composition and design-token work but few original, reusable React component implementations or documented lifecycle hooks were present in the human-authored files.
Responsive & Cross-browser
4/10
Works on all screens and browsers
Responsive-first choices and vendor fallbacks are present via Tailwind screens and custom utilities with scrollbar fallbacks, but advanced cross-browser feature-detection or RTL/i18n plumbing is not evidenced.
Performance Optimization
2/10
Speed of the interface
Little evidence of measured performance work or advanced optimizations; Tailwind and modular CSS reduce runtime cost but there are no bundle-analysis artifacts, virtualization, or RUM measurements in human-authored files.
Accessibility & Semantics
2/10
Usable for everyone
Some semantic form markup and small accessibility-aware utilities exist, but there is no clear a11y testing, ARIA on custom widgets, or focus-management patterns for complex widgets in the human-authored files.
State Management & Data Flow
4/10
Managing data in the app
Server-state and client-state are handled with Redux Toolkit patterns and async thunks; there are Next API route handlers and axios usage but no visible request cancellation, optimistic update patterns, or state machines.
UX & Visual Polish
4/10
Look and feel quality
Strong visual polish and consistent design tokens across CSS modules and Tailwind config show good UX styling and attention to perceived polish, but UX patterns like undo, progressive loading strategies, or documented edge-state flows are limited in the human-authored code.
Industries
Health Care• Middle
Sales & Marketing• Middle
Technologies
TypeScript• Middle
Tailwind CSS
Next.js
React.js
Chakra UI
Redux Toolkit
AWS• mentioned only
JavaScript• mentioned only
Redux• mentioned only
UI• mentioned only
Recommendations
- Lead development of admin dashboards and internal tooling where consistent design tokens, Tailwind theming and CSS modules provide rapid, maintainable UI delivery.
- Own a component library or design system (React components with Storybook and documented accessibility) to turn the theme and utility classes into reusable, testable primitives.
- Implement stronger server-state discipline - add request cancellation, optimistic updates with rollback, and a cache-invalidation strategy for Redux/Next routes.
- Add measurable performance and observability work - bundle analysis, lazy-loading strategy, and before/after LCP/INP measurements for critical pages.
Repositories
The developer's experience in this domain has been verified based on AI analysis of the following repositories:
Junior Game Developer
Confidence: Medium Generalist
Full-stack web developer (junior level) focusing on React/Next.js admin dashboards and small service APIs. The strongest proven skill is frontend state and feature implementation using Redux slices and custom frontend configuration, exemplified by files like src/Redux/Advertisement/Partner/PartnerAdReducer.js and tailwind.config.ts. There is little or no evidence of game-engine work, graphics/shader code, deterministic simulation, profiling-driven optimizations or advanced pipeline automation in the public human-authored code.
Gameplay Systems & Mechanics
How game logic works
Not evidenced in public code
Graphics & Rendering
Drawing game visuals
Not evidenced in public code
Physics & Math
Game physics and math
Not evidenced in public code
Engine Proficiency
3/10
Skill with the game engine
Demonstrates practical engine/proficiency for web app stacks (React/Next/Redux/Tailwind) and custom frontend configuration but no deep engine/editor tooling or custom engine subsystems.
Performance & Frame Budget
1/10
Keeping the game smooth
Small, superficial performance handling (simulated delays) present but no measured optimization, profiler output, or zero-alloc hot-paths.
Content Pipeline & Tooling
3/10
Tools for game content
Evidence of frontend pipeline and configuration (package.json scripts, Tailwind config); no CI, import-postprocessors or advanced asset pipelines were found in the human-authored files.
Industries
Food & Beverages• Middle
Commerce• Junior
Technologies
JavaScript• Junior
Recommendations
- Build and extend admin dashboards and data-driven React frontends using Redux and Tailwind (stateful list pages, CSV export, charts).
- Implement REST API endpoints and small Node.js services for CRUD, authentication and pagination features (token handling and basic validation).
- Own feature-level integrations for commerce and food-delivery flows (payment integration endpoints, order lists, search and filtering).
Repositories
The developer's experience in this domain has been verified based on AI analysis of the following repositories: