Divyanshu Kalra, Developer in Delhi, India
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Divyanshu Kalra

Verified Expert  in Engineering

Machine Learning Developer

Delhi, India
Toptal Member Since
October 30, 2017

Divyanshu is a data scientist and full-stack developer. He’s well versed in various languages such as Python, NodeJS, PHP, MySQL, and JavaScript. He's particularly proud of his academic work; he's published three research papers in his field. The projects that interest him involve web back ends, machine learning, and web scraping.


Statistics, Data Science, Machine Learning, Python
Redis, Node.js, Neo4j, PHP 7
Grand Electronics




Preferred Environment

Unix, Linux

The most amazing...

...thing I've worked on is the Bayesian engine of VWO, I was able to make it 10x faster and give faster results to customers.

Work Experience

Data Scientist

2018 - PRESENT
  • Worked on personalization and the MultiArmedBandit algorithm, production, and R&D.
  • Improve the stats engine by making it 10x faster and reduced the server cost.
  • Created a spam detection algorithm using deep learning with 95% accuracy.
  • Worked on projects like optimal notification sending time, sample size selection, and so on.
  • Made end-to-end API systems with Node.js and Python.
Technologies: Statistics, Data Science, Machine Learning, Python

Web Developer

2017 - 2018
  • Implemented Redis pooling using Node.js.
  • Developed a Django-like framework for Node.js.
  • Built a customizable finite state machine (using PHP/Neo4j) that can be altered and generated using only a JSON file.
Technologies: Redis, Node.js, Neo4j, PHP 7

Web Developer

2017 - 2017
Grand Electronics
  • Built a website from scratch.
  • Created an anti-piracy technology using a 64-bit unique code that helped the company fight piracy of their products.
  • Used PHP, MySQL for the back end.
  • Developed the front end using Material Design.
  • Developed the back end using CSS, JavaScript, jQuery, and HTML.
Technologies: MySQL, PHP, jQuery, CSS, HTML

Android Developer | System Administrator

2017 - 2017
  • Created an OCR application to detect number plates using Google's Android Vision.
  • Developed a graphical dashboard using Graphana to monitor system stats via Collectd and InfluxDB.
  • Built an Android app for tracking number plates using OCR.
  • Engineered a daemon process for tracking system stats.
  • Developed custom dashboards for Graphana.
Technologies: InfluxDB, Collectd, Grafana, Android Studio, Java

Machine Learning Developer

2017 - 2017
  • Worked on a neural net (algorithmic hybrid model).
  • Created a Django front end that lets the user train the neural network and track all the performance of the net. The neural net compared two names and outputted if they are the same name (for user verification).
  • Ensured that the final accuracy of the model was 99.03%.
  • Developed a neural net for anomaly detection.
Technologies: Django, Python 3, Keras, TensorFlow

Web Developer

2016 - 2017
  • Scraped the data of doctors, hospitals, and more using Python's Selenium and Dryscrape libraries.
  • Created a real-time notification system using Node.js, Socket.IO, and PHP.
  • Removed API security holes by using OAuth 2.0 protocol for communication.
  • Built a real-time admin chat application that lets user chat with admin and get support.
  • Implemented PBKDF2 (password-based key derivation function) with salting to store passwords and replace MD5 hashing.
Technologies: JavaScript, MySQL, Python 3, CodeIgniter, PHP

Software Developer

2016 - 2016
  • Created an API test suite using Python's pandas and Requests libraries.
  • Automated the testing of deployed APIs and compare them to their local counterparts.
  • Made the interfacing of multiple APIs faster and easier.
  • Developed a custom doc reader that read the API documentation and fed the response body to the test suite.
  • Created a process to store tokens and other keys that will be used in calling future APIs.
Technologies: Pandas, Python 3

Freelance Web Developer

2015 - 2016
  • Created a website that lets a user add t-shirt designs and allows other users to vote on it. It was built using PHP and MySQL. The passwords were hashed by using PBKDF2 and salts and the website was hosted on a shared server.
  • Developed the front end used CSS, jQuery, and HTML; Bootstrap CSS was used for styling.
Technologies: jQuery, HTML, CSS, MySQL, PHP

Freelance Web Developer

2014 - 2015
ShareGaadi | EventGyan
  • Created a website for EventGyan that was used for managing upcoming events; built HTML, CSS, PHP, and jQuery.
  • Developed a back-end for the site which saved the route the user is going on and if a new user has to go on the same or similar route, the back-end algorithm would match them, as a potential carpooling partner.
  • Built the front end of the site using Bootstrap CSS for styling.
  • Developed a carpooling application for ShareGaadi using the Google Maps API. Google Maps was used to calculate the distance and directions of the trip.
Technologies: HTML, jQuery, CSS, MySQL, PHP

Sentiment Analyzer

Uses Python's Gensim Word2Vec library to map all the words in a tweet as a vector. It analyzes the vectors using a three-layer deep neural net; the net is constructed with TensorFlow in order to detect if the tweet is positive or negative.

Advances in Keystroke Dynamics: 2005-2016

I wrote a research paper that contained a survey of all the techniques used in keystroke analysis for user authentication. It was published in IEEE | IndiaComm Conf 2016.

Classifier Dependent Dimensionality Reduction for Resource Restricted Environments

I wrote a research paper that examined the use of a neural network and GA to reduce the dimensionality of a large dataset according to the needs of the classifier. It was published in Springer | Redset Conf 2017.

Kafka End-to-End Encrypted Chat

This is an end-to-end encrypted, scalable chat app written in Python using TkInter. The back-end used Apache Kafka.

Home Automation

I built an Android app which allows the user to control devices in his house. The user can use voice control via natural language processing (Wit.ai API). The central server was written in Flask for Python 3.5. Raspberry PI and Arduino were used to control the electronic devices.

Color Detect

A program that uses OpenCV to detect the color of the object in front of the camera and then sends the signal to Arduino which recreates that color on an RGB LED screen.

Remote Play

A software that runs on Raspberry Pi and can convert any speaker/headphones into a wireless speaker/headphones. It uses PHP and Python 3 to fetch and play the song.

360° Security Camera

This uses a motor, a webcam, and two Flask servers to generate a live feed. It also gives the client control of the webcam's motor so that the client can get a 360-degree view of the room.
2014 - 2018

Bachelor of Technology Degree in Instrumentation

Netaji Subhas Institute of Technology - Delhi, India


Deep Reinforcement Learning Nanodegree

Udacity with NVIDIA and Unity


TensorFlow, jQuery, Google Maps API, Node.js, Keras, Pandas, WebRTC, Socket.IO, PyTorch


Ansible, Android Studio, Grafana


Data Science


JavaScript, Python, PHP, CSS, Python 3, Java, HTML, PHP 7


Bootstrap 3, Django, Unity, CodeIgniter


Docker, Unix, Apache Kafka, Android, MacOS, Linux


Redis, PostgreSQL, MySQL, Neo4j, InfluxDB


Machine Learning, Algorithms, Statistics, Tkinter, Collectd

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