Shashank Agarwal, Developer in Bangalore, Karnataka, India

Shashank Agarwal

Back-end Developer

Bangalore, Karnataka, India
Toptal Member Since
October 28, 2019

Shashank is a back-end engineer who has worked on a range of products and clients from working on scalability problems in production engineering teams at Razorpay, Urbanclap, and HealthKart to developing MVP products for small businesses. He has a track record of mobilizing resources to start new ventures and drive ideas from inception to execution. Whether it’s projects or organizations, he's a self-starter.

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Go, gRPC, REST, Protobuf, Microservices, Apache Kafka...
Grover Group GmbH
Node.js, Go, PostgreSQL, GraphQL, Apache Kafka, Payment Gateways, TypeScript...
Go, Apache Kafka, RabbitMQ, Redis, MongoDB, MySQL, Java, Architecture...


Bangalore, Karnataka, India



Preferred Environment

Sublime Text, IntelliJ

The most amazing...

...thing I've done is convert a large part of the codebase into rules expression and executed it via rule engine; this improved the success rate of the payments.

Work Experience

2022 - 2022

Go Engineer

  • Designed and developed a lot of microservices for the cross-border payment system, such as compliance, funding, and payout.
  • Wrote complex flows to accurately calculate the conversion rates between different currencies and the arrival time accordingly.
  • Crafted the system using microservices and GRPC on AWS.
Technologies: Go, gRPC, REST, Protobuf, Microservices, Apache Kafka, Amazon Simple Queue Service (SQS), RabbitMQ, Payment Gateways, Fintech, Software Architecture, Amazon Web Services (AWS)
2021 - 2022

Senior Architect

Grover Group GmbH
  • Created and launched the card product from scratch, powered by Solaris bank APIs.
  • Developed end-to-end understanding of how cards are issued in Germany and performed integrations with the existing eCommerce portal.
  • Followed sprints and tracked processes on Jira and slack bots.
Technologies: Node.js, Go, PostgreSQL, GraphQL, Apache Kafka, Payment Gateways, TypeScript, Fintech, Software Architecture
2019 - 2021

Senior Software Developer

  • Led the concept of a smart routing engine that selects the best terminal out of thousands for a payment, serving 500+ TPS.
  • Architected and worked extensively on ​the rule engine (3000 TPS).
  • Performed various tasks like rate limiting and distributed locking via Redis and migrated the entire Redis Cache to cluster mode.
  • Converted a lot of hard code into rules and got it executed by the rule engine.
  • Served as a core team member involved in migrating the huge monolith codebase to a distributed microservice architecture.
Technologies: Go, Apache Kafka, RabbitMQ, Redis, MongoDB, MySQL, Java, Architecture, Microservices, Payment Gateways, Fintech, Software Architecture, Amazon Web Services (AWS)
2017 - 2019

Senior Software Developer

Tila - eCommerce marketplace in middle east
  • Led the team of four engineers and completely build the major platform APIs and services from scratch on a scale.
  • Architected and worked extensively on ​Incentive engine ​which provides real-time discounts and offers using self build rule-engine.
  • Designed and implemented the checkout flow from the cart to placing the order.
  • Involved in all major product level design.
Technologies: Go, eCommerce, ReactiveX, JBoss Drools, Quartz, Apache Kafka, Redis, MongoDB, MySQL, GoLand, Java, Spring Boot, Software Architecture, Spring, Amazon Web Services (AWS)
2016 - 2017

Co-founder and CTO

Osperi - customized beauty products based upon your skin type
  • Built an end-to-end technology infrastructure in Node.js, Mongo, and other BE/FE technologies.
  • Built an auth server for WiFiDog that provides free public wifi to strengthen the marketing efforts.
  • Pioneered and Implemented virtual consultation, reducing customer acquisition costs by 30%.
  • Built a solid scheduling platform to book doctor appointments.
  • Hired multiple developers, followed regular standups, sprint meetings, and more.
Technologies: Firebase, Android, NGINX, EJS, Bootstrap, MongoDB, Node.js, eCommerce, Software Architecture
2015 - 2016

Full-stack Software Developer

Urbanclap - service marketplace
  • Developed a coupon engine (Node.js/Java) that increased user conversion rate by 70%.
  • Worked on the matching algorithm to assign the best possible service provider for the customer request.
  • Developed the consumer Android app from scratch; it has 1+ million downloads.
Technologies: Android, Elasticsearch, MongoDB, Node.js
2014 - 2015

Software Engineer

HealthKart - eCommerce marketplace of health products
  • Worked with a team of five engineers to ship growth-bending products and modularized the codebase.
  • Pioneered and Implemented a customized diet plan feature that resulted in increasing the overall engagement.
  • Developed the eCommerce app from scratch, and it now has 1+ million downloads.
Technologies: Spring Boot, MySQL, Android, Java, eCommerce, Spring


OkCustomer — eCommerce WhatsApp Bot for Digital India

With OkCustomer users don't need any website/App to sell: They can sell directly on WhatsApp through an automated chat.

Things users can do with OkCustomer:

* Create their shop on our Whatsapp bot.
* Accept payments via UPI, credit debit card, and net banking.
* Accept COD orders.
* Generate offer links and share.
* Receive enquires and automatically get new customers.
* Start a reward program.
* Ask customers to book appointments.
* Send interactive offers/discounts/scratch cards.
* Send images, videos, and other media.
* Create quizzes, and stamp collection to start giveaways programs.
* Bulk SMS.
* New product launch updates.
* Pre-book products.
* Customer enquires.

CodersRank — Turn Your Code Into Your Digital Developer Profile and Get Hired Faster
CodersRank gives users a 360-degree dev profile based on the public and private data they hold on various coding sites, allowing them to show off their credentials.

By default, CodersRank only considers public repositories, however, most developers have their code in private repositories. We wanted to give them the chance to improve their scores too by adding their private repositories. Private repos are private for a reason: Therefore, this script extracts only the most important information:

- Number of inserted lines in each commit
- Number of deleted lines in each commit
- Other information—such as remote URLs, file names, emails, names—is hashed, enabling to know if two commits belong to the same file without knowing the file's name.

Moreover, the output is saved to the users' machine and they can check what data is extracted and decide whether they want to share it with us or not.

When a repository is analyzed, two repositories are used: the repo and its library repository. The repository is responsible for recognizing the languages and export the imported libraries. The libraries contain a list of supported libraries, imports, and technologies they belong to.

Osperi exists to provide you customized beauty products based upon your skin type and concerns. I did the complete backend and frontend development of this website which has the functionality of an eCommerce, doctor consultation, chat, and various other features. The stack is Node.js, MongoDB, AWS, Elasticsearch, and WIFI dog.

Captive Portal in Node.js Using WIFI Dog
The complete auth server is written in Node.js and MongoDB which follows all the protocols of WifiDog auth server.

Java library to convert Arbitrary expression into relational query.



Go, Java, TypeScript, Python, JavaScript, GraphQL


REST APIs, Node.js, Protobuf, Quartz, ReactiveX, EJS


Microservices Architecture, Rule-based Programming, Microservices, Agile, REST


Technical Leadership, eCommerce, Payment Gateways, Software Architecture, Redis Clusters, Distributed Systems, Fintech, Prometheus, Architecture


Spring Boot, gRPC, Spring, Bootstrap, NestJS


Jira, Slack, RabbitMQ, Open Rules Engine, IntelliJ, Sublime Text, GoLand, JBoss Drools, NGINX, Kibana, Sumo Logic, Kafka Streams, ELK (Elastic Stack), Amazon Simple Queue Service (SQS)


Apache Kafka, Android, Docker, Kubernetes, Google Cloud Platform (GCP), Heroku, Amazon EC2, Firebase, Amazon Web Services (AWS)


MongoDB, MySQL, Redis, Amazon S3 (AWS S3), PostgreSQL, Elasticsearch


2009 - 2013

Bachelor of Technology Degree in Computer Science

Uttar Pradesh Technical University - Lucknow, India