Data Analyst

Rohit Jaiswal

SQL, BigQuery, and dashboards people actually use.

About

What I do

For 3+ years I worked close to the data, using SQL to track down and fix data issues so the numbers behind a live website stayed accurate, which gave me real respect for data quality. On my own I went further into analytics: querying public datasets in BigQuery, building a Tableau and a Looker dashboard, and training a churn model, to practise the full job end to end. The projects below are that work.

3+: Years working with data
2: Case studies
5★: HackerRank SQL
AZ-900: Azure certified

Skills

Tools I work with

Programming

SQL
Python (Pandas)

Analytics

Data Analysis
Data Validation
Data Quality
Business Reporting
Dashboard Development

Visualization

Tableau
Looker Studio
Excel

Tools

BigQuery
Git
Jupyter Notebook
Streamlit

AI Tools

Claude
ChatGPT

I lean on Claude and ChatGPT day to day for validation checks, summarizing findings, and speeding up documentation.

Experience

Where I've worked

Data Analyst

Oct 2022 – Mar 2026

Cognizant Technology Solutions · OUP India Website Project

Resolved 5–10 data-issue tickets a week for the OUP India publishing website, correcting inaccurate or inconsistent records in the live database.
Wrote SQL queries on PostgreSQL (lookups, filters, and cross-checks) to locate the affected records and trace each issue to its root cause.
Verified the data was correct after every fix before closing the ticket, keeping the site's operational data accurate and consistent.
Worked through a steady ticket queue in a live production environment for 3+ years, keeping resolution turnaround reliable.
Coordinated with the team and business stakeholders to confirm reported issues and that each fix matched what they expected.

Projects

Selected work

A few projects that show how I work with data, from raw SQL to dashboards and a deployed model.

Data Analytics & Customer Insights

2025 – 2026

Customer segmentation, revenue, and retention analysis on a public e-commerce dataset.

Wrote analytical SQL with joins, CTEs, and window functions for segmentation, revenue, and retention reporting.
Analyzed 500K+ sessions to surface traffic and retention patterns.
Used SQL for validation and anomaly checks to catch reporting inconsistencies across large tables.

SQLBigQuery

Read case study

Code

Customer Churn Prediction

2025

A deployed, interactive churn model: enter a customer's details and it predicts whether they'll stay or leave.

Cleaned the data, then compared Logistic Regression, Decision Tree, and Random Forest in Scikit-learn, tuning for recall to catch more churners.
Deployed a Streamlit app where you set inputs like tenure, services, and account details and get a live stay-or-leave prediction.

PythonScikit-learnPandasStreamlit

Read case study

Live demo Code

E-commerce Sales Dashboard

2025

A multi-view Tableau dashboard on retail sales: regional trends, category profitability, customer lifetime value, and a region-by-sub-category heatmap.

Built five linked views: a sales KPI, daily sales trend by region, category revenue vs profit, average LTV by segment, and a region by sub-category heatmap.
Surfaced where revenue and profit diverge across categories, and which regions and customer segments drive the most value.

TableauSuperstore dataset

From the data

Interactive analysis

Two projects you can poke at right here: a slice of my BigQuery work on the thelook_ecommerce dataset, and what drives churn in my Telco model.

Source: BigQuery · bigquery-public-data.thelook_ecommerceSee the queries

Education

Background

Education

B.Tech, Electronics Engineering

2022

KIIT University, Bhubaneswar

CGPA 8.11

Certifications

HackerRank SQL (5-Star)
HackerRank
Microsoft Azure Fundamentals (AZ-900)
Microsoft
Apr 2023