Varanasi, India · Remote
Pankaj Kumar Verma
AI / full-stack product engineer — applied LLM systems, payments, production mobile
Nearly four years shipping web and mobile products end to end across six engineering organisations and five industries. Most of the work below is private client code, so this page is the ledger: what the system was, what I personally built in it, and how much of it is mine.
What I build
Applied AI
OpenAI ReAct agents, streaming in-app assistants, Gemini video analysis, embedding pipelines and vector search behind semantic retrieval. Shipped in a live product, not prototypes.
Marketplace payments
Stripe Connect twice, in two codebases — connected-account onboarding, destination charges splitting a platform fee, and fulfilment driven only by signature-verified webhooks.
Background systems
Queue-driven workers over BullMQ and Redis: feed fan-out, embedding indexers, telemetry sync, reminders, scheduled closures. Terminal failure states and bounded retries.
Mobile release ownership
React Native to the App Store and Play Console — store compliance, Android 15 targeting, New Architecture and major-version upgrades, deep linking, push routing.
Application security
Ownership enforcement at route and service layers to close IDOR classes, bot mitigation on OTP flows, and server-side computation of anything that touches money.
Delivery
A shared CI/CD action library used org-wide, per-PR mobile builds, changed-file linting, static analysis. Deployment time cut ~25%.
Systems
Recco
API · web · React Native — ~90 services, 150+ models, 20 workers
Built the coach marketplace across all three surfaces, including the full Stripe Connect layer: coach onboarding, Checkout, payout setup, and destination charges splitting a configurable platform fee. Bookings are marked paid only from signature-verified webhooks — never the client redirect — covering settlement, expiry, async failure, refund and account-update events.
Built the AI stack: an OpenAI ReAct engine for résumé and LinkedIn enrichment, a streaming in-app companion, a Gemini worker scoring recorded pitch reels, and a vector-indexing worker powering semantic candidate search. Built the fan-out-on-write feed, where per-user timelines are materialised by paired workers on every graph mutation. Built the multi-tenant employer platform from an empty repository. Led a security pass closing IDOR vulnerabilities across six subsystems.
Pinch
Multi-tenant operations platform — manager web portal, staff mobile app
Organisations run facilities — housing societies, campuses — staffed by people assigned recurring tasks. I built the task lifecycle: recurring task structures, mark-complete flows, backdating prevention, and automatic unassignment of a staff member's tasks when they go on leave. Plus attendance edge cases, a four-level role hierarchy crossed with facility scoping, geo-tagged presence verification, and the people and task analytics dashboards managers run on. Production WhatsApp Business API integration, including media compression to fit WABA limits.
My Solar RX
Python · React · React Native — 16 of 17 PRs merged in a three-week engagement
Pulls live data from SolarEdge inverters and tells homeowners whether their panels are earning their keep. Vendor endpoints are slow and rate-limited, so I built a power-flow sync worker behind a Redis-cached API and moved the app screens onto it — the same shape as an embedding indexer, pulling expensive external calls off the request path. Built customer alert delivery over push and email with a daily admin fleet-status digest, which is the real product: a system that silently stops producing costs money every day nobody notices. Led the React Native 0.77 → 0.85 upgrade to React 19 and the New Architecture.
Kizuna Care
Two-sided caregiving marketplace
Families needing care on one side, background-verified caregivers on the other. Built appointment payment processing with platform fees over Stripe — marketplace payments in a second codebase, a year before Recco's. Fixed booking-state correctness: the classic marketplace race where several offers are out, one is accepted, and the rest must be invalidated or two caregivers both believe they are booked. Plus geographic matching within a 200-mile radius, and notification fan-out with a daily 24-hour reminder worker.
Better Software (Jalan Technologies)
Software Engineer → Product Engineer · internal platform, CI/CD library, client delivery
Core engineer on Operate, the organisation-wide internal developer platform — pluggable MySQL and PostgreSQL read-only database providers, custom GitLab host configuration, an AWS CloudWatch log provider and proactive error monitoring. Authored and maintained github-ci, the shared CI/CD action library used across every repository in the organisation, resolving caching and pipeline bottlenecks for a ~25% deployment-speed improvement. Maintained the node-react, flask-react and react-native service templates that seed every new client project — the standard architecture behind the client engagements above. Integrated WhatsApp Business messaging and Flows via Meta's Cloud API.
Artica · Sunny Energy LLC
Software Engineer
Artica (Apr — Sep 2024) and Sunny Energy LLC (Nov 2022 — Aug 2023). The two roles that, with the engagements above, make up the six engineering organisations.
Engineering write-ups
Seventeen write-ups on how these systems actually work — the decisions, the trade-offs and the failures. Client names and data are deliberately absent; these are about the engineering, not who paid for it.
- PaymentsWhen is the money actually there?Building a two-sided marketplace where a booking is only fulfilled once payment has genuinely settled — and why the browser redirect can't be trusted to tell you that.
- ReliabilityThe outage that logged at debug levelA feature degraded silently in production for weeks because three separate fallback paths turned a hard API failure into a quiet one.
- PlatformEvery unfollow is a delete you have to rememberBuilding a fan-out-on-write timeline where each user's feed is materialised rows in a table — and why the hard part is not writing them, it's removing them when the social graph changes.
- SecurityAuthorisation belongs in two placesFinding and closing broken object-level authorisation across six subsystems of a growing API — why the route layer alone isn't enough.
- AI systemsGetting a data structure out of a language modelA tool-calling ReAct agent that turns unstructured documents and third-party profile data into a validated record — and what breaks when you treat model output as trusted.
- MobileOwning a React Native release end to endTaking a cross-platform app from an empty repository to live releases on both stores — signing, provisioning, per-PR builds and the parts of mobile delivery nobody warns you about.
Side projects
Products built on top of the node-react service template — the same base every client project starts from. Bars show my own commits against the repository total, template history included.
Outcry / Khatabook
Ledger and accounting platform with a React Native companion app. I built the ledger and accounting modules across web and mobile.
DairyDiary
Dairy operations management system — API with Docker deployment, plus a React Native app with native Kotlin and Swift layers.
Open source
react-native-durable-queue
Durable job queue for React Native with the semantics of a server-side queue — retries with exponential backoff, dead-lettering, idempotency keys, priorities and delayed jobs — backed by SQLite, in C++, over JSI. Jobs survive app restarts; a job whose worker died mid-run is picked up again rather than stranded.
automated-ai-code-review
Runs AI-assisted review on pull requests — an LLM pointed at a real engineering workflow.
html_to_quill_delta
Library converting HTML into Quill Delta rich-text format. MIT.
React Native library maintenance
Maintained forked patches keeping react-native-fast-image, react-native-video, react-native-image-picker and art compatible with RN 0.75 in production. Opened an upstream compatibility fix to react-native-fast-image — still open.
Availability
Open to engineering roles and contract work — remote, or Bengaluru, Pune, Hyderabad and Goa.