RA
agent session · 10y production experience

Rana Arslan

Senior Full-Stack Engineer — Ruby on Rails · React · AI Integration

I ship production Rails and React systems, then wire retrieval pipelines and LLM agents into them without breaking what already works.

start a sessiondownload resume
years shipping production SaaS
0+
years shipping production SaaS
avg API latency cut on core rewrites
0%
avg API latency cut on core rewrites
background jobs/day hardened
0+
background jobs/day hardened
client products led end-to-end
0+
client products led end-to-end
01perception

Reading the system before touching it.

context_window.summary
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Senior Full-Stack Engineer with 10 years building and scaling
production SaaS — Ruby on Rails and React at the core, with
recent LLM feature work (RAG pipelines, LangChain agents,
Python) embedded into real products. Cut API response times
~45% on a US healthcare platform serving 30+ clinics; built
payments and communications infrastructure end-to-end; led
Rails development and mentoring across 8+ client products.
locationLahore, Pakistan
modeRemote — US / UK / EU / APAC
focusrails · react · llm systems
educationBSc Software Engineering, Riphah…
clock10 years in production
02knowledge base

What gets retrieved when a problem comes in.

Five collections, indexed by domain. Every entry below has shipped in production, not a tutorial.

backend.index
11 entries

// Services, data, and background processing

Ruby on RailsNode.js / ExpressPostgreSQLMySQLRedisSidekiqElasticsearchGraphQLREST APIsRSpec / Capybara / TDDRails Version Upgrades
frontend.index
7 entries

// Interfaces and client-side systems

React.jsTypeScriptJavaScriptTailwind CSSBootstrapjQueryMaterial-UI
ai_llm.index
7 entries

// Retrieval, agents, and model integration

PythonLangChainRAG PipelinesAI AgentsOpenAI APIAnthropic APICustom Response Tuning
devops_cloud.index
7 entries

// Infra, delivery, and reliability

AWSDockerCI/CDHerokuGoogle CloudDigitalOceanGit
integrations.index
6 entries

// Third-party systems wired into production

StripeTwilioSendGridShopifyQuickBooksOAuth
03reasoning trace

Five roles, one chain of thought.

Each step: the problem as it actually looked, then what shipped to fix it.

01

Full-Stack Developer · Westside Children's Therapy

Aug 2024 — Present — US · Remote

A Rails platform serving 30+ therapy clinics is slow under load and clinic staff are drowning in manual admin work.

  • Cut average API response time by ~45% by refactoring N+1 queries, adding Redis caching, and optimizing PostgreSQL indexes.
  • Shipped 12+ scheduling and patient-management features end-to-end (Rails API + React), cutting manual admin work by an estimated 8–10 hours/week.
  • Hardened the Sidekiq job pipeline processing 20,000+ jobs/day, reducing failures on billing-critical workflows by over 90%.
02

Senior Software Engineer · ClikDone

Apr 2023 — Aug 2024 — US · Remote

A founder needs a production web application built from zero — backend, frontend, infrastructure, payments, and comms — with no existing team.

  • Independently architected and built the entire web application from concept to production launch.
  • Built the full payments and communications layer (Stripe, SendGrid, Twilio) powering automated invoicing, email, and SMS across thousands of monthly transactions with zero payment-data incidents.
  • Delivered 15+ core product features working directly with the founder, operating as de facto product owner + engineer.
03

Senior Software Engineer · TruMed Systems

Apr 2021 — Mar 2023 — US · Remote

A US healthcare vaccine-inventory platform needs a broader partner-facing API surface and reports that take minutes are blocking operations.

  • Designed and documented 25+ new API endpoints enabling partner and reporting integrations.
  • Cut heavy report generation from minutes to under 10 seconds by rewriting complex MySQL queries and adding targeted indexes.
  • Converted 30+ mock-ups into responsive production UI (React components) and resolved user-reported defects across testing phases.
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Senior Software Engineer · Procare Solutions

Apr 2020 — Apr 2021 — US · Remote

The #1 US childcare platform (37,000+ centers) needs reliable REST APIs for school programs, children, and guardian records — plus far better test coverage.

  • Built REST API endpoints managing school programs, children, and guardian records, with full serializers, documentation, and automated tests.
  • Raised test coverage on owned modules from ~40% to 85%+, cutting regression bugs during release cycles.
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Software Engineer → Senior · DevCache

Mar 2016 — Apr 2020 — Lahore · On-site

8+ client products need consistent Rails delivery, legacy modernization, and a team that can review and ship safely.

  • Led Rails development across 8+ client products over 4 years — APIs, background jobs, third-party integrations — maintaining 10+ live production sites at 99.9% uptime.
  • Performed Rails version upgrades and legacy modernization across client codebases, keeping products secure and maintainable.
  • Mentored 5 junior developers and introduced code review standards, reducing production bugs by ~30%.
04action log

Function calls that shipped to production.

Selected work, framed the way I actually think about it: input, invocation, output.

sync_pipeline.run(target: "versa_cloud_erp")

Versa Cloud ERP — Shopify Sync

input » Modular ERP needs orders, shipments, payments, and inventory kept in lockstep with Shopify in real time.

  • Built the Shopify API integration syncing orders, shipments, payments, and inventory.
  • Kept a modular ERP system consistent across storefront and warehouse without manual reconciliation.
Ruby on RailsShopify APIPostgreSQLSidekiq
agent.deploy(mode: "rag+workflow_automation")

AI Feature Work — RAG + Agents

input » Legacy SaaS products need LLM features added on top of internal documentation without breaking existing workflows.

  • Built RAG pipelines over internal documentation for grounded, on-domain answers.
  • Shipped LangChain agents for workflow automation and custom LLM response tuning.
PythonLangChainOpenAI APIAnthropic API
optimize.rewrite(target: "clinic_api", metric: "p95_latency")

Healthcare Platform Performance Overhaul

input » A multi-clinic Rails platform is buckling under N+1 queries and unindexed reads at 30+ clinic scale.

  • Refactored N+1 queries and added Redis caching across hot paths.
  • Cut average API response time by ~45% and stabilized a 20,000+ job/day Sidekiq pipeline.
Ruby on RailsPostgreSQLRedisSidekiq
infra.provision(layer: "payments+comms", from: "zero")

Payments & Communications Infrastructure

input » A new product needs invoicing, email, and SMS running reliably at thousands of transactions per month, from a blank repo.

  • Built the full Stripe, SendGrid, and Twilio integration layer end-to-end.
  • Powered automated invoicing, email, and SMS with zero payment-data incidents.
StripeSendGridTwilioRuby on Rails
05memory

persist_session()

Open channels below. No contact form, no gatekeeping — just a direct line.

email meresume
phone+92 305 4009230
locationLahore, Pakistan · Remote
githubranaarslan11linkedinrana-arslan-fullstack-developerportfolioitsarslan.com