Backend Systems
High-performance Rails applications, APIs, PostgreSQL query tuning, Sidekiq workflows, Redis caching, AWS, and Kubernetes.
Berlin based - 16+ years shipping software
Saroj Maharjan builds reliable Rails systems and practical AI products.
Senior Software Engineer specializing in Ruby, AI, and scalable backend systems for fintech, insurtech, developer tools, and founder-led products.
16+
years in production Rails
2M+
daily events optimized at PAIR Finance
8
engineers mentored as a team lead
12 yrs
Ruby community leadership
What I build
High-leverage systems that stay understandable.
AI Applications
RAG products, LLM orchestration, pgvector search, RubyLLM, LangChain, agent workflows, and cost-aware prompting.
Engineering Leadership
Architecture, mentoring, code review culture, product-minded delivery, open source stewardship, and community building.
Featured work
Products, not just repositories.
Rails - AI - RAG - LLM - Agentic AI
GemChat
AI Chat for Ruby Gem Documentation
Ask questions about Ruby gems with version-specific answers grounded in README files, guides, and API references. Uses RAG with vector embeddings, reranking and semantic search as well as Agentic AI Tool calls.
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Rails - AI - Hotwire - Stimulus
BuyList.shop
Shared Shopping Lists for Every Household Run
Collaborative shopping lists for households, couples, roommates, and teams. Includes AI-powered item capture, receipt scanning, and smart refill suggestions.
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Rails - Encryption - MeroShare - Automation
LaganiSaathi
IPO & Right Share Automation for Nepalese Investors
Apply for IPO, FPO, and right shares across family Demat accounts from one workflow. MeroShare automation with encrypted credentials and confirmation-gated submission.
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Next.js - Community - Social Networking
NepaliExpat
Connecting Nepali Expats Worldwide
A community platform for Nepali expats to connect, share experiences, and stay informed about events and opportunities in their home country.
Visit site →Experience
Selected roles where scale, clarity, and shipping mattered.
Senior Ruby on Rails Developer - PAIR Finance
Worked on payment infrastructure, PostgreSQL optimization, APIs, Sidekiq, AWS/Kubernetes, Hotwire delivery, and AI-assisted engineering workflows.
Senior Software Engineer - Ideon
Took features from concept to production, helped scale APIs and service boundaries, and kept latency stable during rapid usage growth.
Engineering Manager & Senior Software Engineer - WhiteHat Engineering
Led Ruby on Rails delivery across fintech, healthtech, blockchain, and AI projects while mentoring an eight-person engineering squad.
Technical Lead - CloudFactory
Joined as a founding employee and worked across backend development, Scrum Master responsibilities, and DevOps for a distributed workforce platform.
Open source
Ruby gems published to the ecosystem.
navi_client
Ruby client work published to RubyGems and used across production Ruby projects.
- Version
- 1.4.7
- Downloads
- 98,491
unit_validator
Validation utility from early Rails ecosystem work.
- Version
- 0.2.2
- Downloads
- 12,122
nepali_number
Nepali number formatting support for Ruby applications.
- Version
- 0.1.0
- Downloads
- 337
Community
Ruby ecosystem work beyond the job title.
Writing