manojOS · boot sequence
0%
welcome to manoj's desk _
draw mode · press ESC to stop
🐛 catch the bugs!
⏱ 20s 🐛 caught: 0 missed: 0
quack 🦆
~ ~ ~
DEPLOY
FRIDAY
NIGHTS.
(kidding. please don't.)
,MK '26
hey recruiter 👋
scroll? no. click
the laptop.
TODO:
▢ write tests
☑ break things
☑ fix things
remember: every
webhook wants to
retry. let it.
HOURS UNTIL
THE WEEKEND
·
♪ ♫ ♪
DDIA
ch. 8: the trouble with distributed systems
...clocks lie. networks lie. so does your monitoring...
9:41
slack
kafka is fine
$ hello, friend ▊
click to enter

✨ secret drawer

🐛 play bug-hunt
🎉 throw confetti
🎨 party mode
🔄 reset the desk
📝 leave a note

Manoj's Desk

👆 click the laptop for the "real" portfolio
crafted by manoj
manoj kumar
designed and engineered by hand · 2026
brewed on too much coffee · powered by curiosity
manojka.swe@gmail.com
linkedin · portfolio
coffees347
uptime99.9%
secrets0/38
resume.pdf
MANOJ KUMAR
+1 (682) 216-2727 | manojka.swe@gmail.com | LinkedIn | Portfolio

Summary

Senior full stack developer with 5+ years building production systems across React, Angular, Java/Spring Boot, and Node.js for large enterprise client engagements serving millions of end users. Hands-on across React (Hooks, Context, Redux), Next.js, Angular/RxJS, Java/Spring Boot microservices, Node.js, RESTful APIs, AWS, Docker, and Kubernetes, with a track record modernizing legacy Angular and monolithic codebases into distributed systems while mentoring developers in Agile teams. Signature impact: built and scaled payment features on platforms serving 8M+ merchants, cut dashboard load time 57% (4.2s to 1.8s), lifted Lighthouse accessibility from 62 to 98, and held 99.9% availability under high concurrency. Comfortable moving across frontend and backend stacks to fit whatever a client engagement demands.

Skills

  • Languages & Frameworks: Java, Spring Boot, Spring Batch, Spring MVC, Angular, React.js, TypeScript, JavaScript (ES6+), Python, Node.js, Redux, GraphQL, Next.js, Express.js, FastAPI, Hibernate
  • Frontend & Visualization: React.js (Hooks, Redux, Context API), Next.js, Angular, Tailwind CSS, Material UI, Storybook, SSR/SSG, dynamic imports, code splitting, WCAG 2.1, ARIA, responsive design, PWA, A/B testing, accessibility
  • Cloud & DevOps: AWS (EC2, S3, Lambda, EKS, CloudFront, CloudWatch), Docker, Kubernetes, Terraform, Jenkins, GitHub Actions, CI/CD pipelines, serverless architecture, auto-scaling, zero-downtime deployments, disaster recovery
  • Databases & Caching: Oracle DB, PostgreSQL, MySQL, MongoDB, Redis, DynamoDB, query optimization, caching strategies, database sharding, replication
  • Web & API Development: RESTful APIs, WebSocket, GraphQL, OAuth 2.0, JWT, RBAC, ABAC, OpenAPI/Swagger, gRPC, Nginx
  • Distributed Systems: Apache Kafka, event-driven architecture, microservices, circuit breakers, fault tolerance, high-availability design, legacy modernization, CQRS, DDD, clean architecture, monolith-to-microservices migration
  • Performance & Observability: Grafana, Prometheus, ELK Stack, CloudWatch, New Relic, Sentry, P95 latency optimization, distributed tracing, MTTD optimization, memory leak debugging, bundle analysis, CDN integration
  • Testing & QA: Jest, Cypress, JUnit, Mockito, Selenium, SonarQube, Postman, contract testing, TDD
  • Security: PCI DSS, OWASP Top 10, OAuth 2.0, JWT, RBAC, ABAC, CSP
  • AI & GenAI: LLM integration, prompt engineering, OpenAI API, GitHub Copilot, Claude, scikit-learn, feature engineering, predictive analytics, recommendation systems
  • Agile & Collaboration: Agile/Scrum, Kanban, Jira, Confluence, sprint planning, SOLID principles, code reviews, technical mentoring, cross-functional collaboration, stakeholder management
  • Domain Expertise: FinTech (payments, subscriptions), e-commerce, SaaS platforms, enterprise analytics

Experience

Software Engineer · DoJoGa | USA Jul 2025 - Present
  • Led development of a high-availability booking platform on Kafka-backed event-driven architecture, preventing contention and holding 99.9% uptime under load.
  • Owned PostgreSQL schema design and indexing, then added Redis caching to offload read-heavy queries, cutting P95 API latency from 400ms to 150ms.
  • Built Java/Spring Boot microservices for booking workflows and Node.js Lambda functions to process Kafka events, cutting processing time from 2 hours to 10 minutes.
  • Developed a Python/scikit-learn predictive pipeline to forecast enrollment and surface early risk signals, cutting student dropout by 15%.
  • Designed a React/TypeScript frontend with dynamic imports and route-level code splitting to reduce initial load time and cut booking abandonment.
  • Instrumented Grafana/Prometheus dashboards with OpenTelemetry tracing, cutting incident mean-time-to-detect from 18 minutes to under 4.
  • Configured Kubernetes autoscaling with Jenkins CI/CD and blue-green deploys to absorb peak enrollment traffic spikes with zero downtime.
  • Leveraged GitHub Copilot and Claude across Java/Spring Boot development, generating unit tests, optimizing SQL queries, and accelerating Kafka integration and troubleshooting.
Software Engineer · SakhaTech Information Systems Pvt. Ltd. | Client: OneDine, USA Sep 2022 - Jul 2023
  • Integrated Amazon Pay, Global Payments, and Heartland APIs under peak transaction load, catching and patching a critical OAuth 2.0 vulnerability that risked $250K in losses.
  • Built a WebSocket real-time notification system in Node.js, cutting support ticket resolution time from 2 hours to 25 minutes.
  • Refactored Redux by normalizing state and adding memoized selectors, eliminating cascading re-renders and cutting page load time 41% (3.2s to 1.9s).
  • Spearheaded migration from Angular to React Hooks and built a Storybook component library, increasing component reuse across product features.
  • Engineered SSR architecture with Next.js to improve SEO, growing organic search traffic by 35% within 3 months.
  • Mentored 15 developers through code reviews and engineering-standards guidance, lifting Lighthouse accessibility scores by 50 points.
Software Engineer · Infiniti sync Global Pvt. Ltd. | Client: Razorpay, India Nov 2021 - Aug 2022
  • Delivered core engineering on Razorpay's subscriptions product for a platform serving 8M+ merchants, owning dashboard features generating $250M+ in monthly GMV.
  • Led frontend performance work with chunked fetching, react-window virtualization, and code-splitting, cutting dashboard load time 57% (4.2s to 1.8s).
  • Built multi-step subscription and refund workflows with React Hook Form, Yup, and autosave drafts, cutting merchant time-to-first-subscription from 3 days to 6 hours.
  • Architected Java/Spring Boot payment APIs and webhook infrastructure with idempotent capture and HMAC signing, handling 10M+ monthly events with zero duplicate-charge incidents.
  • Engineered WCAG 2.1 AA remediation across keyboard nav, ARIA, and focus traps, lifting Lighthouse accessibility from 62 to 98 and unblocking stalled enterprise deals.
  • Shipped RBI-mandated e-mandate changes ahead of the regulatory deadline across several React UI flows, keeping recurring-payment merchants compliant with zero critical regressions.
Full Stack Developer · Machstatz Business Solutions Pvt. Ltd. | Client: JSPL, Borosil, India Jun 2020 - Oct 2021
  • Delivered frontend engineering on a real-time analytics platform ingesting billions of data points/hour, built for analysts across 40+ enterprise customers.
  • Designed interactive data-viz layers with D3.js and Chart.js for zoomable time-series charts, cutting chart interaction latency 77% (1.2s to 280ms).
  • Engineered a theme-aware UI system with CSS Modules and centralized design tokens, cutting custom-skin delivery time from 3 weeks to 4 days.
  • Migrated 12+ legacy Angular/RxJS modules to React with zero customer-impacting downtime, cutting frontend build time 71% (4.5 min to 1.3 min).
  • Integrated long-lived WebSocket subscriptions into the React frontend with back-pressure handling and auto-reconnection for stable, live-updating views.
  • Implemented Java/Spring Boot REST APIs and PostgreSQL/MySQL layers with Spring Security and RBAC, cutting reporting response time 68% (6.5s to 2.1s).
Associate Software Developer · Maruti Techlabs | India Jul 2019 - May 2020
  • Contributed frontend engineering on client SaaS products, shipping React/Redux features across auth, profiles, and transactional workflows over 10 sprints.
  • Built responsive, mobile-first layouts with SASS and Flexbox/Grid across Chrome, Firefox, Safari, and Edge, cutting layout bug reports 40%.
  • Implemented Axios data-fetching with centralized interceptors for auth, loading states, retries, and error normalization, cutting frontend boilerplate by 30%.
  • Developed Java/Spring Boot REST endpoints and MySQL schemas for the React frontend, keeping P95 response times under 250ms across core workflows.
  • Wrote Jest and JUnit/Mockito tests, raising coverage on owned modules from 45% to 75% and catching regressions before they reached staging.

Education

Master of Science, Data Science · University of Texas at Arlington · Aug 2023 - May 2025
Bachelor of Engineering, Computer Science and Engineering · RNS Institute of Technology, Bengaluru · Aug 2015 - Jul 2019

Certification

Front End Web Developer Nanodegree I & II · Udacity (co-created by AT&T, Google and GitHub)

⬇ download resume.pdf
Notes File Edit View Help
🔋
,
~/manoj.dev/notes.txt
~ notes ~

Hi, I'm Manoj.

welcome to my desk ↓

status
open to roles
experience
5+ years
reach me
manojka.swe@gmail.com
Full stack developer who likes the hard parts: React & Angular frontends, Java/Spring Boot backends, payments infrastructure at scale. 5+ years shipping production systems for enterprise clients serving millions of users, currently building a booking platform at DoJoGa.

I'm a senior full stack developer who moves across the whole stack to fit whatever an engagement demands. Frontend, mostly React (Hooks, Context, Redux), Next.js, and Angular/RxJS; backend, mostly Java, Spring Boot, and Node.js. Cloud-native by default: AWS, Docker, Kubernetes, CI/CD, with a habit of turning legacy Angular and monolithic codebases into distributed systems that don't fall over.

I've done this at DoJoGa (a booking platform on Kafka-backed event-driven architecture), OneDine (payment gateway integrations and real-time notifications for a restaurant tech platform), Razorpay (subscriptions infrastructure for a platform serving 8M+ merchants), Machstatz (real-time analytics for enterprise clients like JSPL and Borosil), and Maruti Techlabs (SaaS product engineering). Different clients, same underlying problems.

Things I care about: performance that's actually measured (P95 latency, bundle size, load time), accessibility that isn't an afterthought (WCAG 2.1 AA, Lighthouse scores in the 90s), and AI woven into the day-to-day (Copilot, Claude, LLM-backed features that hold up in production). I'm the engineer who cut dashboard load time 57% and lifted Lighthouse accessibility from 62 to 98 by actually measuring where the work was going.

⚡
currently
Software Engineer at DoJoGa. Building a booking platform from scratch on Kafka + Spring Boot + React, plus an ML-driven enrollment forecasting pipeline. Open to conversations about full-stack systems and performance work.
~ m.

by the numbers

0
merchants on the Razorpay platform I built for
0
dashboard load time cut, 4.2s → 1.8s
0
Lighthouse accessibility score, up from 62
0
years shipping production systems
manoj@desk:~/playgrounds$ ./run --interactive
loading 3 live demos...

click things. break things.

three systems problems you'll hit the moment you have more than one user. payments, healthcare, messaging, analytics , same hard parts. try to break them.

01. webhook idempotency

LIVE

any webhook source , Stripe, GitHub, Twilio, Shopify, your own services , will retry if you don't ack in time. your job: process exactly once. strategy: every event carries an event_id, you cache what you've processed. try hitting "duplicate" a bunch.

0processed
0dropped
$0total charged

02. exponential backoff + jitter

LIVE

some downstream service , a database, a payment processor, an EHR, a third-party API , flakes out 60% of the time. retry up to 5 times with base · 2^n + jitter. jitter prevents the thundering herd. every run is different.

0attempts
0mselapsed
,result
// hit run to start

03. token bucket rate limiter

LIVE

every API needs one. capacity 10, refill 2/sec. each request spends a token. empty → 429. try to spam faster than it refills.

0200 ok
0429
10tokens
bucket10/10
manoj.dev › work › experience

where i've worked.

5 roles · 5+ years · payments, infra, and platform work.

Software Engineer
DoJoGa
'25 → now
0→1
product built
-63%
p95 latency
0
audit findings

Building a platform from scratch on Spring Boot + Kafka + React. Passed third-party security audit at launch with zero findings.

Software Engineer
OneDine
'22 - '23
5k
TPS sustained
3
gateways integrated
$250k
fraud prevented

Integrated 3 payment gateways sustaining 5,000 TPS. Spotted OAuth vulns in an OWASP review, estimated $250K in prevented fraud.

Software Engineer
Razorpay
'21 - '22
8M+
merchants
$250M
monthly GMV
10M+
events/mo · zero dupes

Owned Subscriptions on 8M+ merchant platform. Built dashboards for 150K+ merchants processing $250M+ monthly GMV. Webhook infra shipping 10M+ events per month with zero duplicates.

Full-Stack Engineer
Machstatz
'20 - '21
B+/hr
data points ingested
12+
modules migrated
0
downtime

React/Redux analytics ingesting billions of data points per hour. Migrated 12+ legacy Angular/RxJS modules to React with zero downtime.

Associate Software Developer
Maruti Techlabs
'19 - '20
20+
features shipped
<250ms
API p95
45→75%
test coverage

Shipped 20+ React features on a SaaS product. Built Spring Boot endpoints with sub-250ms P95. Raised module test coverage from 45% → 75%.

things I can actually do.

grouped by what I reach for. not a wishlist. not a buzzword cloud.

🧠 languages
Java TypeScript JavaScript (ES6+) Python SQL
🎨 frontend
React (Hooks, Redux, Context) Angular / RxJS Next.js Tailwind CSS Material UI Storybook
⚙️ backend
Spring Boot Spring MVC Node.js Express.js REST GraphQL
🤖 AI / GenAI
LLM Integration GitHub Copilot Claude OpenAI API Prompt engineering scikit-learn Feature engineering Recommendation systems
📡 data & messaging
Kafka Redis PostgreSQL MySQL MongoDB DynamoDB
☁️ cloud & devops
AWS (EC2, Lambda, EKS) Docker Kubernetes Terraform GitHub Actions CI/CD
🎯 production practices my thing
WCAG 2.1 / ARIA P95 latency optimization Code splitting Circuit breakers OAuth 2.0 / JWT Distributed tracing

things i've built.

6 items
● personal ● worked at
worked at
D
dojoga
a booking platform, built from scratch.
a high-availability booking platform on Kafka-backed event-driven architecture, holding 99.9% uptime under load. Owned the PostgreSQL schema and Redis caching layer that cut P95 API latency from 400ms to 150ms, plus a Python/scikit-learn pipeline forecasting enrollment and dropout risk. Passed a third-party security audit at launch with zero findings.
+ tap to learn more
worked at
O
onedine
payment gateway integrations at peak load.
integrated Amazon Pay, Global Payments, and Heartland APIs sustaining 5,000 TPS, and caught a critical OAuth 2.0 vulnerability that risked $250K in losses. Built a WebSocket real-time notification system, refactored Redux to kill cascading re-renders, and led the Angular-to-React migration.
+ tap to learn more
worked at
R
razorpay
subscriptions infra for 8M+ merchants.
owned Subscriptions on Razorpay's 8M+ merchant platform, building dashboards processing $250M+ monthly GMV and webhook infrastructure shipping 10M+ events a month with zero duplicate charges. Cut dashboard load time 57% and lifted Lighthouse accessibility from 62 to 98.
+ tap to learn more
worked at
M
machstatz
real-time analytics ingesting billions of points/hr.
frontend engineering on a real-time analytics platform for 40+ enterprise customers, with D3.js/Chart.js time-series views cutting chart interaction latency 77%. Migrated 12+ legacy Angular/RxJS modules to React with zero customer-impacting downtime.
+ tap to learn more
worked at
M
maruti techlabs
SaaS product engineering, first job out.
shipped 20+ React/Redux features across auth, profiles, and transactional workflows, plus Java/Spring Boot REST endpoints holding P95 response times under 250ms. Raised test coverage on owned modules from 45% to 75%.
+ tap to learn more
personal
this site
an interactive desk portfolio you're using right now.
an interactive desk experience with draggable items, a fake operating system inside the laptop, three live playgrounds, achievements, drawing mode, and a hidden drawer. you're inside it.
+ tap to learn more
🎧
NOW PLAYING
life outside work
manoj · hobbies playlist
0:00 ∞

manoj's life outside work

the playlist that runs when the laptop is closed · 7 tracks

1
🍜
cooking new recipes
the kitchen sessions
1,847 plays
4:32
2
🎮
video games
console and keyboard
2,398 plays
6:12
3
📺
tv, but responsibly
one more episode
1,204 plays
3:48
4
💪
the gym
mon/wed/fri, mostly
588 plays
3:02
5
🌐
building websites for fun
sites like this one
412 plays
5:17
6
🍽
exploring restaurants
a new place every week
306 plays
2:48
7
✈️
weekend travels
anywhere < 4 hours away
156 plays
5:21
MK
Manoj Kumar ● online · usually replies fast
hey manoj 👋
saw your portfolio. you made a desk? today · just now
yep. it was more fun than a landing page. today · just now
fair. we're hiring senior full-stack. strong systems engineers only. interested? today · just now
definitely. let's talk. today · just now
say hi↗
reply times are fast. usually.
email call linkedin portfolio resume.pdf
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