Backendsystems thathold.
I am Utkarsh Jaiswal, a backend engineer building multi-tenant Node.js and PostgreSQL systems, data migrations, search infrastructure, and AWS deploy paths for products that cannot afford fragile foundations — and I leave the team able to run them.
- Role
- Software Development Engineer II at Shuru, on the Balio platform
- Focus
- Multi-tenant NestJS/PostgreSQL systems, data migration, and the AWS layer
- Open to
- Senior roles, and a small number of contract engagements
Direct
[email protected]- 24
- California cities and counties served
- 142K
- legacy compliance and expense reports
- 4TB
- JSON searched in Elasticsearch
- +18%
- ITR filings after the 26AS parser
Selected work
Three systems, and what changed
Each one is the same shape: what was breaking, what I built, and what it did to the numbers.
Replacing a 38-database legacy compliance system while production stays online
Shuru · Software Development Engineer II · Mumbai
A 20-year-old grant and housing-compliance system serves 24 California cities and counties, with a legacy estate spanning 38 databases and 142K compliance and expense reports — and it has to be replaced without taking production offline.
I own the backend architecture for the NestJS/PostgreSQL V2 platform: a JSONB-backed form engine so agencies configure conditional fields and tenant overrides without a deployment, revision snapshots and field-level diffs that preserve grant amendment audit trails, and RBAC with per-resource CRUD/APPROVE/REJECT permissions enforced through route guards and query-level tenant scoping. A Python migration tool carries 200–500-field legacy records across per-jurisdiction mappings, validating budgets and required fields, folding in client Excel corrections, and emitting JSON for V2 imports.
24
Production V1 stays read-only throughout, and notifications and program-window recomputation run off the request path on SQS, SES, and EventBridge-triggered ECS tasks.
- NestJS
- TypeScript
- PostgreSQL (JSONB)
- Python
- AWS (ECS, SQS, SES, EventBridge)
Read the case study
Protecting search over a 4 TB Elasticsearch corpus from runaway API clients
WhiteCrow Research · Software Engineer · Mumbai
Talent search ran over a 4 TB JSON corpus, and an unthrottled API surface meant one heavy client could degrade the platform for everyone.
I owned backend development for three years — REST APIs, data models, and client integrations — optimised the Elasticsearch queries and database operations behind search, and built an anti-scraping rate limiter with per-client request budgets and Fibonacci-escalating lockout windows for repeat offences inside 24 hours.
4TB
I also automated application deployments to the AWS instances through deployment scripts, implemented Google login for authentication, and used MySQL events for scheduled database maintenance.
- Node.js
- Elasticsearch
- MySQL
- AWS
- REST API design
Read the case study
Automating tax-data extraction behind an 18% rise in ITR filings
Fisdom (now part of Groww) · Software Engineer · Jaipur
Self-filing stalled wherever a taxpayer had to key in data that already sat in a government document, and assisted filing needed a route through government partner channels.
I built a Python Form 26AS parser to automate taxpayer-data extraction, and implemented E-Return Intermediary (ERI) client registration with eMitra and CSC integrations so partner channels could file on a taxpayer's behalf.
+18%
ITR filings rose 18%, and the PHP CodeIgniter portal was secured with CSRF protection.
- Python
- PHP (CodeIgniter)
- MySQL
- ERI
- eMitra / CSC
Read the case study
What I do
Four kinds of work
Scoped engagements with a target we agree before I start. Not open-ended staff augmentation.
Legacy replacement and migration
Multi-tenant platforms
APIs and integrations
Infrastructure and deploys
Writing
Notes from production
Multi-tenant data models, migrations, search, and rate limiting — written from the systems above.
Sharding didn't just scale us. It cut the bill.
Vertical scaling has a brutal cost curve — every tier up charges a premium on top of the extra CPU and memory. Notes on how sharding a 4 TB search corpus turned that curve into a fleet of commodity nodes, and where the savings actually came from.
Claude wrote it in 40 seconds. Production killed it in 4.
AI coding tools optimize for green tests — one user, one region, no contention. Production asks about stale reads, hot partitions, flat rate limits, and failover without fencing. Notes on where the gap actually is.
Fibonacci lockouts: rate limiting a scraper that keeps coming back
Per-client request budgets over a 4 TB search corpus, and lockout windows that escalate along a Fibonacci sequence — why that curve rather than exponential backoff, and what the 24-hour window is really for.
Free tools
Free things I built to stop explaining
Browser-only, no sign-up, nothing sent anywhere. The rate limiter playground runs six algorithms against real traffic shapes and hands you the config.
Rate limiter playground
Run six rate limiting algorithms against bursty, scraping and thundering-herd traffic, watch what each one blocks, and copy the nginx, Express, NestJS or Redis config that implements it.
OpenColour picker
One colour, two readings — as a highlight behind black text and as a flat fill, with the contrast ratio against near-black underneath.
OpenAI Token Cost Calculator
Estimate your LLM API spend across OpenAI, Claude, and Gemini using current token pricing.
OpenOpenAI Cost Calculator
Calculate exact costs for GPT-4o, GPT-4 Turbo, and O1 models.
OpenClaude Cost Calculator
Estimate spend for Claude 3.5 Sonnet, Opus, and Haiku.
OpenGemini Cost Calculator
Calculate costs for Gemini 1.5 Pro and Flash models.
OpenAI Image Cost Calculator
Compare cost of AI image generation across Midjourney, DALL-E, and Stable Diffusion.
OpenAI Video Cost Calculator
Estimate spend for AI video generation based on duration and provider.
OpenAI Prompt Generator
Craft high-quality structured prompts using personas, constraints, and clear goals.
OpenJSON Formatter
Format, validate, and minify JSON strings to stop squinting at API responses.
OpenResume ATS Checker
Check if your resume is ATS-friendly and optimize keywords to get past the bots.
OpenAI ROI Calculator
Determine if AI automation is saving you money by comparing human hours vs API costs.
OpenSaaS Pricing Calculator
Model your MRR, churn, and LTV to determine a sustainable price point.
OpenContext Window Calculator
Measure text in tokens and see how it fits into various LLM context windows.
OpenCPM Calculator
Calculate Cost Per Mille to measure the efficiency of your ad spend.
OpenYouTube Revenue Calculator
Predict revenue based on views, CPM, and niche for YouTube content.
Open
Recommended
Tools I point people at
Two things I recommend when the question is not one I bill for.
Hosting
Where to put a small site
Not everything needs ECS and a Postgres cluster. For a brochure site, a WordPress install, or a first project that has to be live this week, shared hosting is the right answer — and Bluehost is what I point people at when they are not going to maintain a server.
Shared and WordPress plansNo server to maintainLive the same day
Privacy
What a VPN is actually for
It does not make you anonymous. It moves who can see your traffic from the network you are sitting on to the provider you picked — which is the trade you want on hotel wifi, and very little use against the sites you are logged into. ICE Privacy is where I send people when that is the trade they need.
Traffic off untrusted wifiYour ISP sees one endpointNot an anonymity cloak
Work together
Two ways in
Hiring for a senior role, or bringing a system that has to hold. Pick the door that fits — I read everything and reply myself, usually within a day.
For hiring teams
Looking for someone who has already run APIs, rate limits, search, and deploys in production — not someone who will learn it on your roadmap.
For contract work
Selected engagements on Node/TypeScript backends, PostgreSQL, Elasticsearch, and AWS — queues, mail, rate limiting, and the deploy path. A small number at a time.