About Neeraj Kumar

Building reliable backend systems at scale.

Backend engineer at Datachecks. I write FastAPI services, Celery workers, and data comparison tools that run against production databases. Day-to-day is mostly making data validation fast and reliable across different database targets.

FastAPI servicesCelery performanceDatabase integrationsEnterprise deployment

Experience

Work history

Currently active

Datachecks

Dec 2023 – Present

SDE-I · Backend Engineer

Datachecks · India

Working on Datachecks' comparison platform — FastAPI services, Celery workers, data-diff performance, multi-database integrations, and enterprise deployments.

FastAPI control planeCelery workersComparison engine tuningDatabase connector integrationsOffline enterprise deployment

Major achievements

Replaced hash-based diffing with memory-based diffing to improve large-table comparison throughput.
Implemented a per-column diff threshold strategy so over-sampled columns are skipped and compute is redirected toward broader difference coverage.
Extended platform compatibility across MSSQL, MySQL, Oracle, Databricks, Sybase IQ, Sybase ASE, Presto, and Trino.
Delivered a full air-gapped deployment on a bank-owned RHEL server with zero internet access.
Built Croma WhatsApp backend flows for Demo Installation Status, Request Installation, and My Account.
Improved Celery worker stability for long-running validation and comparison tasks.

Platform areas

Stormbreaker

Control Plane API

FastAPI service layer orchestrating comparison jobs, async execution, reporting, and deployment-ready operational workflows.

FastAPICeleryRabbitMQPostgreSQL

DCS SDK

Comparison Engine

Config-driven CLI and SDK for cross-database validation, schema checks, row diffing, reporting, and result packaging.

PythonClickSQLAlchemyJinja2

Enterprise Deployment

Air-Gapped Infra

End-to-end offline deployment for a bank environment on RHEL, including dependency packaging and isolated runtime setup.

RHELDockerPython packagingSystem configuration

Croma WhatsApp Flows

Service Automation

Customer-facing backend flows layered on platform services for installation tracking and account requests.

FastAPIWorkflow APIsService integrations

9AI

Oct 2023 – Nov 2023

Python Developer

9AI · India

Backend work on Invotbot-API — real-time messaging with Redis Pub/Sub and MongoDB analytics queries.

WebSocket supportRedis Pub/SubMongoDB analytics

Major achievements

Worked on real-time messaging paths using Redis Pub/Sub patterns.
Supported WebSocket-oriented communication flows for the backend team.
Wrote MongoDB aggregation pipeline queries for visibility and analytics use cases.

Platform areas

Invotbot-API

Realtime Backend

Backend support for websocket-oriented communication and analytics workloads.

PythonRedisMongoDBWebSockets

Stack inventory

Tools used in actual work

Languages

PythonTypeScriptSQLC++

Backend

FastAPICelerySQLAlchemyClickREST APIs

Databases

PostgreSQLRedisMongoDBMSSQLMySQLOracle

Analytics / Warehouses

DatabricksPrestoTrinoBigQuerySnowflake

Infrastructure

DockerRabbitMQKubernetesHelmRHEL

Tooling

BeautifulSoupaiohttpAlembicPytestGitHub Actions

Education

Academic background

Master of Computer Applications (MCA)

Lovely Professional University · Phagwara, Punjab

Aug 2022 – Jun 2024 / CGPA: 8.30

Bachelor of Computer Applications (BCA)

Lalit Narayan Mishra Institute of ED and SC · Patna, Bihar

Aug 2019 – Jul 2022 / CGPA: 8.21

Currently active

Datachecks

Dec 2023 – Present

SDE-I · Backend Engineer

Datachecks · India

Working on Datachecks' comparison platform — FastAPI services, Celery workers, data-diff performance, multi-database integrations, and enterprise deployments.

FastAPI control planeCelery workersComparison engine tuningDatabase connector integrationsOffline enterprise deployment

Major achievements

Replaced hash-based diffing with memory-based diffing to improve large-table comparison throughput.
Implemented a per-column diff threshold strategy so over-sampled columns are skipped and compute is redirected toward broader difference coverage.
Extended platform compatibility across MSSQL, MySQL, Oracle, Databricks, Sybase IQ, Sybase ASE, Presto, and Trino.
Delivered a full air-gapped deployment on a bank-owned RHEL server with zero internet access.
Built Croma WhatsApp backend flows for Demo Installation Status, Request Installation, and My Account.
Improved Celery worker stability for long-running validation and comparison tasks.

Platform areas

Stormbreaker

Control Plane API

FastAPI service layer orchestrating comparison jobs, async execution, reporting, and deployment-ready operational workflows.

FastAPICeleryRabbitMQPostgreSQL

DCS SDK

Comparison Engine

Config-driven CLI and SDK for cross-database validation, schema checks, row diffing, reporting, and result packaging.

PythonClickSQLAlchemyJinja2

Enterprise Deployment

Air-Gapped Infra

End-to-end offline deployment for a bank environment on RHEL, including dependency packaging and isolated runtime setup.

RHELDockerPython packagingSystem configuration

Croma WhatsApp Flows

Service Automation

Customer-facing backend flows layered on platform services for installation tracking and account requests.

FastAPIWorkflow APIsService integrations