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.
Ruby on Rails Consultant 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.
Next.js - LiveKit - AI - Voice
PrepRole
Voice-first interview practice for developers
Paste a job post and resume, then rehearse out loud with an AI Interviewer tailored to the role. Get a hiring-style Scorecard, practise Recruiter Screen through System Design, and improve over time across mock and real interviews.
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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 - Encryption - MeroShare - Automation
Lagani Saathi
Apply, track, and calculate for your whole family
Lagani Saathi is the household NEPSE platform for Nepalese investors: bulk-apply IPO and right shares across family Demat accounts, sync portfolio and WACC, watch dividend news, and run fee and capital-gains calculators - with MeroShare work only after you confirm.
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Beta · Swift - SwiftUI - macOS - Health
Desk Health
Move reminders for long Mac desk days
A native Swift/SwiftUI menu bar app that nudges you to move when you have been sitting too long. Call and video awareness, guided exercises, water tracking, and Focus Filters — all on-device, no surveillance.
BetaExperience
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
gemchat
Indexes the docs of the gems in your own bundle and serves BM25 search over it from the command line.
- Version
- 0.1.0
- Downloads
- 172
Community
Ruby ecosystem work beyond the job title.
Writing