Waqas Taj

Backend • Middle • Lahore, Pakistan • UTC+05:00 • Work permits: Pakistan • English: B2 • Available in 2 weeks

Software Developer

6+ years exp

Ruby

Python

TypeScript

SQL

JavaScript

Node JS

Elixir

Perl

PHP

Security & Auth: 4/10

Active 5 days ago

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Overview

Technical skills

Timeline

Roles

Overview

A backend Rails developer (middle level) with practical SDET habits focused on RSpec-based unit and controller testing. The strongest proven skill is writing conventional RSpec controller specs and test infrastructure as shown in spec/controllers/tasks_controller_spec.rb and the project-level rails_helper/ spec_helper setup. There is little or no evidence of contract testing, CI/test orchestration, performance testing or advanced QA practices in the public code.

Phone

Technical skills

Languages

Ruby

Python

TypeScript

SQL

JavaScript

Node JS

Elixir

Perl

PHP

Ruby

RSpec

Ruby on Rails

Sidekiq

Devise

Factory Bot

Pundit

Kaminari

Hotwire

Stimulus

DevOps

AWS

AWS Lambda

Docker

Terraform

Heroku

Puppet

Amazon S3

Kubernetes

Databases

Apache Kafka

Redis

PostgreSQL

ElasticSearch

MySQL

Frontend

Tailwind CSS

Vue.js

Sass

React.js

Next.js

Playwright

Cypress

Selenium

Other

FastAPI

LLM

Nest.JS

Amazon CloudWatch

Amazon EC2

Amazon ECS

GitHub

Jest

Mocha

RuboCop

Git

GitLab

Rest API

Memcached

Brakeman

Bitbucket

RabbitMQ

CI/CD

Jenkins

Nginx

GraphQL

ESLint

Webpack

PostCSS

Frontend

CircleCI

WebSockets

IAM

VPN

Timeline

Senior Software Engineer • Senior

Xquic • Full-Time

Dec 2024 to Present 1 Year 9 Months Partially remote

Led development of an OTA reconciliation engine for hotel revenue recovery, replacing a monolithic system with a Python/FastAPI service architecture. Improved system performance and stability through a major Ruby on Rails upgrade and database and application query optimization using PostgreSQL and Redis caching. Owned infrastructure modernization by migrating from Heroku to AWS with Terraform and coordinated third-party API integrations for automated customer onboarding and reconciliation.

Python

FastAPI

Ruby

Ruby on Rails

PostgreSQL

Redis

Terraform

AWS

Heroku

Senior Software Engineer • Senior

Devsinc • Full-Time

Mar 2024 to Dec 2024 9 Months Lahore In office

Delivered scalable multi-tenant features for concert and benefits platforms, including database performance improvements via table partitioning and replacing slow ORM queries with optimized raw SQL. Built and maintained asynchronous job processing with Sidekiq, reducing job failures by implementing retry and DLQ-style handling. Completed a modernization of a legacy PHP/Perl codebase to Ruby on Rails and TypeScript, adding BDD feature testing with RSpec and Cypress plus secure REST API development and performance tuning.

Ruby

Ruby on Rails

TypeScript

SQL

Sidekiq

RSpec

Cypress

Software Engineer • Middle

Devsinc • Full-Time

Aug 2021 to Mar 2024 2 Years 7 Months Lahore In office

Rebuilt and scaled data extraction systems using microservices and Playwright, achieving major scraping speed improvements and supporting distributed scraping with VPN proxies. Automated infrastructure provisioning for scraping workflows using Puppet and optimized execution with AWS Lambda. Developed payment and education platform capabilities, including Dockerized financial workflow modules for PCI-aligned chargeback automation and frontend enhancements using Vue.js, Tailwind CSS, and Rails with unit testing via RSpec.

Playwright

AWS

AWS Lambda

Puppet

Docker

Vue.js

Tailwind CSS

Ruby on Rails

RSpec

Associate Software Engineer • Middle

InvoZone • Full-Time

Feb 2020 to Aug 2021 1 Year 6 Months Lahore In office

Designed Kafka-based microservices for financial reconciliation workflows, adding webhooks and schema contracts to improve data integrity. Integrated Salesforce for event and registration flows and implemented API synchronization for financial system operations. Built large-scale bulk import pipelines to support high-volume data ingestion and downstream processing.

Apache Kafka

Salesforce

Middle Backend Developer Confidence: Medium API Engineer

Backend Ruby on Rails developer at an early-to-mid level (Middle) with practical experience building CRUD web apps and a small CLI tool. The strongest proven skill is implementing Rails authentication and authorization, as shown by config/initializers/devise.rb and the app/policies/* files. There is limited evidence of production-grade scalability, advanced database tuning, distributed systems, or deliberate resilience patterns in the public code.

API Design

2/10

How well APIs are designed

Basic Rails controller patterns and request specs are present but there is no evidence of API versioning, idempotency keys, consistent error contracts, or advanced pagination design.

Evidence

waqas-taj/todo-app-rails-7/spec/controllers/tasks_controller_spec.rb: controller request specs for TasksController waqas-taj/bugzila/app/controllers/bugs_controller.rb: controllers with CRUD and custom actions (assign, change_status)

Data Layer & Database

3/10

Working with databases

There is a visible migration history, schema with indexes and seeds; however there is no sign of transactional boundaries, tuned raw SQL, explicit isolation-level handling or N+1 mitigation code.

Evidence

waqas-taj/bugzila/db/migrate/20210924164413_create_bugs.rb: schema migration for bugs waqas-taj/bugzila/db/migrate/20210921093818_create_projects.rb: schema migration for projects waqas-taj/bugzila/db/schema.rb: table definitions, indexes and foreign keys

Scalability & Performance

1/10

Handling load and speed

Minimal scalability work is evidenced; only basic cache_store settings and commented job adapter hints exist, no queue consumers, cache invalidation strategy, or measured performance changes.

Evidence

waqas-taj/bugzila/config/environments/development.rb: cache_store and caching toggles waqas-taj/bugzila/config/environments/production.rb: commented active_job.queue_adapter and cache_store mentions

System Architecture

2/10

Overall system structure

Code shows reasonable folder/module separation for Rails and a small CLI tool, plus policy-based authorization, but there is no multi-service decomposition, service contracts, or purposeful config/secret management beyond Rails credentials usage.

Evidence

waqas-taj/bugzila/app/policies/project_policy.rb: separation of authorization rules waqas-taj/weatherman/weatherman.rb: small CLI app with modular structure (Reader, Computate, Display)

Security & Auth

4/10

Protecting data and access

Clear use of Devise for authentication and Pundit-style policies for authorization indicate security awareness; credentials usage and reasonable Devise settings are present, but there is limited evidence of token lifecycle management, input sanitation beyond framework defaults, or a dependency audit.

Evidence

waqas-taj/bugzila/config/initializers/devise.rb: Devise configuration using Rails credentials and secure defaults waqas-taj/bugzila/app/policies/bug_policy.rb: authorization rules for bug-related operations

Reliability & Observability

2/10

Stability and monitoring

There are basic logging and environment configurations plus test setup and RSpec coverage which help reliability, but advanced observability patterns (metrics, structured correlation IDs beyond request_id, retries with backoff, graceful shutdowns) are not present.

Evidence

waqas-taj/bugzila/config/environments/production.rb: log_tags including :request_id and logger configuration waqas-taj/todo-app-rails-7/spec/rails_helper.rb: RSpec test bootstrap and Devise test helpers

Verified artifacts

chatwoot/chatwoot• ★ 37.2K

Expertise

Ruby• Middle

Technologies

PHP

Node JS

Elixir

Perl

Rest API

Nest.JS

GraphQL

RabbitMQ

FastAPI• since 2024

Ruby on Rails• since 2021

Apache Kafka• since 2020

Kaminari

Pundit

Recommendations

Build and own small-to-medium Rails web services with authenticated endpoints using Devise and Pundit, focusing on API contracts and versioning.
Expand reliability work by adding background job consumers, idempotency for mutating endpoints, and retries with backoff for external calls.
Add observability and performance work such as structured logging, metrics dashboards, load testing, and targeted query optimization.
Harden data-layer skills by practicing transactional boundaries, explicit locking where needed, and writing/updating migration chains for schema evolution.

Repositories

The developer's experience in this domain has been verified based on AI analysis of the following repositories:

bugzila weatherman todo-app-rails-7

Middle QA Engineer Confidence: High SDET

Test Automation Frameworks

4/10

Building automated tests

Basic, working test automation stack present: RSpec + FactoryBot + Devise test helpers and controller specs. Evidence of conventional test setup but no advanced fixtures, parallelization, mock servers or flake mitigation.

Evidence

waqas-taj/todo-app-rails-7/spec/controllers/tasks_controller_spec.rb waqas-taj/todo-app-rails-7/spec/rails_helper.rb waqas-taj/cash_register_api_only/spec/rails_helper.rb

Test Coverage & Strategy

3/10

What and how to test

Tests cover common happy and some negative paths at controller/model level but follow typical tutorial patterns and lack risk-based tagging, property-based tests, or mutation testing evidence.

Evidence

waqas-taj/todo-app-rails-7/spec/controllers/tasks_controller_spec.rb waqas-taj/todo-app-rails-7/spec/spec_helper.rb

API & Integration Testing

3/10

Testing how parts work together

API-focused app exists with controller specs and JSON helpers, indicating API testing ability; no contract/schema testing, idempotency or integration-with-containers evidence.

Evidence

waqas-taj/cash_register_api_only/spec/controllers/carts_controller_spec.rb waqas-taj/cash_register_api_only/spec/rails_helper.rb

Performance & Load Testing

Testing speed under load

Not evidenced in public code

Bug Reporting & Analysis

Finding and describing bugs

Not evidenced in public code

CI Test Integration

Running tests automatically

Not evidenced in public code

Expertise

Unit & Component Testing• Middle

Industries

Commerce• Middle

Technologies

Python• since 2024 • Middle

JavaScript

TypeScript• since 2024 • Middle

SQL• since 2024

Ruby• since 2021 • Middle

Selenium

Cypress• since 2024

Playwright• since 2021

Terraform• since 2024

Puppet• since 2021

CircleCI

WebSockets

Heroku• since 2024

Jest

CI/CD

Jenkins

Git

AWS• since 2021

Docker• since 2021

Kubernetes

Nginx

RSpec• since 2021

Mocha

Devise

Sidekiq• since 2024

RuboCop

Factory Bot

Hotwire

Stimulus

Brakeman

Bitbucket

AWS Lambda• since 2021

Amazon EC2

GitHub

GitLab

Amazon S3

IAM

Amazon ECS

Amazon CloudWatch

VPN

Recommendations

Expand automated test depth by adding contract/schema validation for APIs (e.g., JSON schema tests) and introduce explicit negative/error-case tests for HTTP 401/422/500 scenarios.
Add CI integration (GitHub Actions/GitLab CI) with matrix runs, per-test artifact capture and a reasoned retry/quarantine policy so test results are actionable in CI.
Invest in integration tests that use isolated fixtures or lightweight containers (testcontainers or equivalent) for dependencies to raise confidence for API and data-layer behaviours.
Introduce mutation testing or targeted boundary/invariant-based tests to expose weak assertions and increase the value of the existing test suite.

Repositories

The developer's experience in this domain has been verified based on AI analysis of the following repositories:

bugzila todo-app-rails-7 cash_register_api_only

Junior Frontend Developer Confidence: Medium UI Engineer

A junior UI engineer focused on building static, responsive HTML and CSS interfaces. Their strongest proven skill is crafting responsive sectioned layouts and CSS-driven UI elements as shown in credo_ui_task/index.html with supporting styles such as header.css and service_section.css. There is little to no evidence of JavaScript-driven state management, automated testing, build tooling, or accessibility automation in the public code.

UI Component Architecture

2/10

How interface parts are built

Basic sectioned HTML structure and CSS partitioning exist but there is no component architecture, module boundaries, or reusable component patterns.

Evidence

credo_ui_task/index.html: distinct header, service, about_me, slider, blog and form sections implemented as static HTML

credo_ui_task/header.css: styles scoped to header section showing manual separation of concerns

Responsive & Cross-browser

3/10

Works on all screens and browsers

Responsive work is present via media queries for small screens, but no advanced fluid layout techniques or RTL/i18n readiness.

Evidence

credo_ui_task/header.css: @media screen and (max-width: 768px) responsive rules

credo_ui_task/service_section.css: mobile-specific adjustments for .service_box and .service_row

Performance Optimization

1/10

Speed of the interface

No measurable performance work or tooling; images and assets are referenced statically without lazy-loading or srcset.

Evidence

credo_ui_task/index.html: multiple <img> tags (images/hero-img.png, blog images) included without loading=lazy or responsive srcset

Accessibility & Semantics

2/10

Usable for everyone

Some semantic elements (nav, header, footer) and alt text exist, but accessibility is partial and lacks ARIA on custom controls and focus-management considerations.

Evidence

credo_ui_task/index.html: use of <nav>, <header>, <footer> and alt attributes on images

credo_ui_task/index.html: icon elements include aria-hidden in places but no keyboard or focus handling for menu icon

State Management & Data Flow

1/10

Managing data in the app

No client-side state management or async handling; forms and inputs are static with no validation, cancellation, or optimistic update patterns.

Evidence

credo_ui_task/index.html: contact form inputs and textarea present with no client-side scripting or validation

credo_ui_task/form_section.css: styling for form controls but no behavior logic

UX & Visual Polish

3/10

Look and feel quality

Visually polished static UI with measured styling (skill bars, layout, color choices) but lacking progressive UX patterns like skeletons, loading states, or undo flows.

Evidence

credo_ui_task/service_section.css: styled service cards and .circle icon treatment

credo_ui_task/aboutme_section.css: CSS skill-bar with ::before/::after for percentage badges

Expertise

HTML & CSS• Junior

Technologies

Frontend

Vue.js• since 2021

Webpack

Tailwind CSS• since 2021

Next.js

React.js

Sass

PostCSS

ESLint

Recommendations

Assign to static landing pages, PSD-to-HTML conversions, and small responsive site builds where strong CSS skills are the priority.
Have them convert repeated sections into reusable components inside a modern framework (React/Vue) to gain component architecture and state-management experience.
Pair them with an accessibility engineer to add keyboard focus handling, ARIA for custom controls, and automated a11y checks.
Introduce basic frontend toolchain and performance work: image optimization (srcset, lazy loading), simple linting, and lightweight build tooling.

Repositories

The developer's experience in this domain has been verified based on AI analysis of the following repositories:

credo_ui_task waqas-taj