Open to backend and platform roles

Rajat
Sharma

I build the systems behind the screen: multi-tenant SaaS on Kubernetes at IBM, and event-driven services on Kafka and Cassandra.

See my work Résumé (PDF) ↗

📍 Toronto, OntarioGitHub ↗LinkedIn ↗

guest@rajatjc: ~

❯

500K+Kafka events a day under watch by a monitor I built

65%lower lookup latency after a Cassandra schema redesign

10+production Kubernetes clusters shipped to with GitOps

3 µsper write in lsm-kv, my storage engine (JMH)

01 · about

Reliable systems, measured results.

Toronto, ON

I'm a software developer at IBM in Markham, on Maximo Small SaaS: a multi-tenant platform that runs Maximo Manage for many customers on Kubernetes and OpenShift. Day to day I write Go and Python services, Helm charts, Terraform and GitOps pipelines, and the tools our SREs use to see the health of every tenant.

Before that I spent a year and a half on IBM Envizi, building Java and Spring Boot microservices on Kafka and Cassandra for ESG reporting.

I care about systems that fail safely, APIs that are hard to misuse, and numbers that prove a change worked. Outside work I build things to understand them, like a storage engine and a toy bank, and I solve problems on LeetCode and CodeChef.

At work

Tenant lifecycle, identity (OIDC) and SRE tooling for Maximo SaaS at IBM.

Building

lsm-kv, an LSM-tree key-value store in Java 21 with a live web UI.

Shipping

Loonie Ledger, a demo neobank, one service at a time on GitHub.

2022 – 2024 · MontrealMaster of Applied Computer Science

Concordia University · GPA 3.6 / 4.3 · Golden Key Scholar

2017 – 2021 · New DelhiB.Tech, Information Technology

Guru Gobind Singh Indraprastha University · GPA 3.9 / 4.3

02 · projects

Things I've built to understand them.

Two projects you can play with right here, plus a game that's live on its own domain. Each demo is a small model of the real system, running in your browser.

lsm-kv

A log-structured merge-tree key-value store, built from scratch in Java 21. It's the storage design behind Cassandra, RocksDB and LevelDB.

3 µsper write (JMH)

17×cheaper lookups for missing keys, thanks to Bloom filters

CRC-checked write-ahead log with crash recovery. Replay stops cleanly at a torn tail.
Memory-mapped SSTables with sparse indexes and Bloom filters, plus size-tiered compaction through a streaming k-way merge.
Dependency-free HTTP API on virtual threads, with a live UI that shows flushes, compactions and pods being replaced in Kubernetes.

Java 21
Gradle
JUnit
JMH
Docker
Kubernetes

Live demo ↗Code on GitHub ↗Free tier: the first load can take about a minute.

try it: a tiny lsm-kvruns in your browser

write-ahead log1 record

PUT grape=2

memtable (sorted, in memory)1/4

grape=2···

sstables on disk, newest firstcompacts at 4

SST-2 · 4 keys

apple=4date=1olive=8plum=9

SST-1 · 4 keys

apple=3fig=5kiwi=7mango=12

Try PUT, GET or DELETE. Four writes fill the memtable.

Loonie LedgerPublishing now

A demo Canadian neobank: three services in three languages that never call each other. Every transfer is checked for fraud and compliance before any money moves.

Java and Spring Boot payments service with a double-entry ledger and a transactional outbox, so no event is ever lost.
Python fraud scoring and Node.js compliance consume Redis Streams consumer groups: at-least-once delivery, idempotent handlers.
SHA-256 hash-chained audit log, and a browser ops console that runs kubectl, redis-cli and psql against the live system.

Java 21
Spring Boot
Python
FastAPI
TypeScript
Redis Streams
PostgreSQL
Kubernetes

Code on GitHub ↗

try it: send moneysame rules as the real services

paymentsJava · holds funds

streamRedis · outbox event

fraudPython · scores 0–100

complianceNode · FINTRAC-style

Pick a scenario. Each transfer is held, checked by two independent services, then settled or sent for review.

Happy Peeler

A free browser game. A blade sweeps across the board, and you tap to shave strips off fruit, vegetables, gadgets and planets. Clear every bit of skin in five peels or fewer.

Fruit, gadgets, stickers and planets, all drawn on a 2D canvas with Path2D, at five motion levels from still to wild. No framework or game engine.
Each run is scored by counting the skin pixels left on the canvas, so the result matches exactly what the player sees.
Worldwide rankings on Cloudflare Pages Functions and D1. Finish times are stored only as counts per 100 ms bucket, so every run is ranked without keeping anything about the player.

JavaScript
Canvas 2D
Web Audio
Cloudflare Pages
Cloudflare D1
SQL

Play it ↗

happypeeler.comTap a screen to play that item

Avocado

Phone

Earth

Earlier work

DreamShops

A shopping-cart REST backend with products, categories and carts, secured with Spring Security and JWT.

Java
Spring Boot
Spring Security
PostgreSQL
Docker

CareerLinkup

A job portal for job seekers and employers, with role-based access and CircleCI deployments.

Python
Flask
SQLAlchemy
SQLite
CircleCI

Graph Coloring

Compares online graph-coloring algorithms, First Fit and CBIP, on generated graphs.

Python
Flask
Jupyter

03 · experience

Six years of backend work.

From telecom network management to ESG reporting to multi-tenant SaaS. Pick a role to see what I did there.

Software Developer @ IBM

Maximo Small SaaS · Apr 2026 – Present · Markham, ON

Build and run a multi-tenant Maximo Manage-as-a-Service platform on Kubernetes and OpenShift, across 19 container images and 11 Helm charts, with every change gated by Helm tests and Tekton pipelines.
Re-keyed tenant identifiers so tenants can migrate between tenant groups, and automated Db2 setup on Amazon RDS with stored procedures, removing hand-run steps from provisioning.
Built a Go tenant-health API and a Next.js SRE dashboard linked to Instana, Loki and Grafana, so SREs can see provisioning, deletion and stuck tenants in one place.
Closed SQL-injection paths in a Python helper, added secret scanning, patched Go dependency CVEs, and wrote Terraform for AWS accounts with PR-driven Atlantis plans.

Go
Python
Kubernetes
OpenShift
Helm
Tekton
Argo CD
Terraform
AWS
Db2
Next.js

04 · skills

What I work with.

Tools I've used in production or in the projects above.

Languages

Java
Go
Python
TypeScript
SQL
Scala
C++
Bash

Backend

Spring Boot
FastAPI
Flask
Node.js
REST
Kafka
Redis Streams

Data

Cassandra
PostgreSQL
Db2
MySQL
MongoDB
Redis
DynamoDB

Platform

Kubernetes
OpenShift
Docker
Helm
Argo CD
Tekton
Terraform
AWS
GitHub Actions

Observability

OpenTelemetry
Instana
Grafana
Loki
OIDC / OAuth

Testing

JUnit
JMH
Testcontainers
Pytest
Jest
Cypress

Competitive programming & awards

2018LeetCode ratingKnight 1848CodeChef rating4 star 1676HackerEarth rating

Top 15%Golden Key ScholarConcordia

05 · contact

Let's build something reliable.

I'm open to backend and platform roles in Toronto or remote. Email is the fastest way to reach me, and LinkedIn works too.

Say hello ↗

RajatSharma