Shashank is available for hire
Hire ShashankShashank Agarwal
Verified Expert in Engineering
Back-end Developer
Bengaluru, Karnataka, India
Toptal member since October 28, 2019
Bio
Shashank is a senior architect who has worked on a range of products and clients and built scalable distributed back-end systems serving P99 and P999 latency for companies such as Razorpay, Nylas, Grover, and UrbanCompany. Shashank 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.
Portfolio
HPE GreenLake
Go, Amazon Web Services (AWS), gRPC, Containerization, Docker, Kubernetes...
Nylas
Go, Temporal, PostgreSQL, Kubernetes, Helm, Terraform, Apache Kafka...
Kappa Pay
Go, gRPC, REST, Protobuf, Apache Kafka, Amazon Simple Queue Service (SQS)...
Experience
Availability
Part-time
Preferred Environment
Sublime Text, IntelliJ IDEA, GoLand
The most amazing...
...thing I've done is convert a large part of the codebase into rules expression and execute it via a rule engine; this improved the success rate of the payments.
Work Experience
Go Developer
2023 - 2023
HPE GreenLake
- Developed a Harmony Access Manager that mediates access requests to data resources. Applications or users request access to data resources, which can be S3 objects, Apache Kafka brokers, or many other things.
- Implemented the Raft consensus algorithm to construct an in-memory permission storage service within a highly scalable distributed environment.
- Enabled other services like Access Manager and Credential Manager were communicating with the raft service via GRPC.
- Built the entire system from scratch and worked directly with the Chief Architect, Ted Dunning.
- Set up metrics for monitoring via Prometheus and Grafana.
Technologies: Go, Amazon Web Services (AWS), gRPC, Containerization, Docker, Kubernetes, Python, Raft Consensus Algorithm, Prometheus, Grafana, Infrastructure, Team Leadership, CI/CD Pipelines, APIs
Tech Lead and Senior Software Architect
2022 - 2023
Nylas
- Launched a distributed data stream service to deliver events to customer destinations on a large scale. Provisioned an ETL pipeline for the ETL flow enabling users to create a destination with Snowflake, Kafka, and Pub/Sub.
- Built a webhook service from scratch with 3,000 transactions per second (TPS).
- Assigned to lead a team for their data streams infra project.
- Followed the internal agile process which this enterprise company already had in place.
- Interacted with other teams frequently as the project required a lot of communication with clients and other teams. Also prioritized the sprint planning.
- De-prioritized our existing tasks and experienced a significant amount of context switching, making it quite a challenging lead role.
Technologies: Go, Temporal, PostgreSQL, Kubernetes, Helm, Terraform, Apache Kafka, Google Cloud Platform (GCP), Snowflake, Redis, Jira, Microservices, Amazon S3 (AWS S3), Amazon EC2, Docker, Technical Leadership, Microservices Architecture, Prometheus, Kibana, Architecture, REST, REST APIs, Software as a Service (SaaS), Back-end, GitHub, Back-end Development, SQL, Relational Databases, API Integration, Leadership, Infrastructure, Team Leadership, Kafka Streams, CI/CD Pipelines, APIs
Senior Software Architect
2022 - 2022
Kappa Pay
- Designed and developed numerous microservices for the cross-border payment system, including 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, Apache Kafka, Amazon Simple Queue Service (SQS), RabbitMQ, Payment Gateways, Fintech, Software Architecture, Amazon Web Services (AWS), Terraform, Helm, Kubernetes, Google Kubernetes Engine (GKE), Distributed Systems, REST APIs, Jira, Microservices, Amazon S3 (AWS S3), Amazon EC2, Docker, PostgreSQL, Technical Leadership, Microservices Architecture, Prometheus, Kibana, Architecture, Python, GraphQL, Back-end, GitHub, GitHub Workflows, Back-end Development, SQL, Relational Databases, API Integration, Leadership, Card Payments, Payment Processing, Digital Payments, Accounting, Infrastructure, Kafka Streams, CI/CD Pipelines, APIs
Tech Lead and Senior Architect
2021 - 2022
Grover Group GmbH
- Created and launched a card product from scratch, powered by Solaris bank APIs.
- Developed an end-to-end understanding of how cards are issued in Germany and performed integrations with the existing eCommerce portal.
- Led the pre-paid cards team and designed the initial architecture with limited resources. As we got more clarity, we started building the team along with the engineering manager.
- Created OKRs, used t-shirt sizing, worked in 2-week sprints, and had daily standups and regular 1-on-1s, ensuring everyone was on the same page.
- Scaled our lean squad to six developers within two years and launched the pre-paid card in partnership with Solarisbank. Continued to grow steadily, with the maximum number of transactions reaching 20 requests per second (RPS).
- Assigned on-call devs as it was a 100% remote team working in different time zones.
Technologies: Node.js, Go, PostgreSQL, Apache Kafka, Payment Gateways, TypeScript, Fintech, Software Architecture, Terraform, Kubernetes, Google Kubernetes Engine (GKE), Helm, Distributed Systems, REST APIs, Jira, Microservices, Amazon S3 (AWS S3), Amazon EC2, Docker, Google Cloud Platform (GCP), gRPC, Technical Leadership, Microservices Architecture, Prometheus, Kibana, Architecture, NestJS, JavaScript, GraphQL, REST, Back-end, GitHub, GitHub Workflows, Back-end Development, SQL, Relational Databases, API Integration, Leadership, Card Payments, Payment Processing, Digital Payments, Next.js, Accounting, Infrastructure, Team Leadership, Kafka Streams, CI/CD Pipelines, APIs
Senior Software Developer
2019 - 2021
Razorpay
- 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 with 5,000 TPS.
- Performed tasks such as rate limiting and distributed locking via Redis and migrated the entire Redis Cache to cluster mode.
- Joined as a senior software developer and worked on their core payment infra. I was later assigned to lead a team for a new product called Smart Routing.
- Migrated a massive monolith codebase to a distributed microservice architecture. The main challenge was to migrate from the old system to the new one and develop this new product and integrate it progressively.
- Started building the team even without an engineering manager. Handled the hiring, set up SOPs with the PM, and created a plan.
- Learned a lot about leadership while building this new product. Razorpay was a company moving from a high-growth startup to an enterprise. Smart Routing has multiple products, with the peak traffic reaching 8,000 RPS.
Technologies: Go, Apache Kafka, RabbitMQ, Redis, MongoDB, MySQL, Java, Architecture, Payment Gateways, Fintech, Software Architecture, Amazon Web Services (AWS), Terraform, Helm, Distributed Systems, REST APIs, Jira, Microservices, Amazon S3 (AWS S3), Amazon EC2, Docker, Google Cloud Platform (GCP), PostgreSQL, Technical Leadership, Microservices Architecture, Open Rules Engine, Rule-based Programming, Prometheus, Kibana, GraphQL, REST, Software as a Service (SaaS), Back-end, GitHub, Back-end Development, SQL, Relational Databases, API Integration, Leadership, Card Payments, Payment Processing, Digital Payments, Accounting, Infrastructure, Team Leadership, Kafka Streams, CI/CD Pipelines, APIs
Senior Software Developer
2017 - 2019
TiLa
- Led a team of four engineers and completely built the major platform APIs and services from scratch on a scale for TiLa, an eCommerce marketplace in the Middle East.
- Architected and worked extensively on an incentive engine that provides real-time discounts and offers using a self-build rule engine.
- Designed and implemented the checkout flow from the cart to place the order.
- Involved in all major product level design and managing team members.
Technologies: Go, eCommerce, ReactiveX, JBoss Drools, Quartz, Apache Kafka, Redis, MongoDB, MySQL, GoLand, Java, Spring Boot, Software Architecture, Spring, Amazon Web Services (AWS), Distributed Systems, REST APIs, Jira, Microservices, Amazon S3 (AWS S3), Amazon EC2, Docker, PostgreSQL, Technical Leadership, Microservices Architecture, Kibana, Architecture, TypeScript, NestJS, JavaScript, REST, Back-end, GitHub, Back-end Development, SQL, Relational Databases, API Integration, Infrastructure, Kafka Streams, CI/CD Pipelines, APIs
Co-founder and CTO
2016 - 2017
Osperi
- 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, NGINX, EJS, MongoDB, Node.js, eCommerce, Software Architecture, Distributed Systems, REST APIs, Jira, Microservices, Amazon S3 (AWS S3), Amazon EC2, Docker, PostgreSQL, Microservices Architecture, Kibana, Architecture, JavaScript, REST, CTO, Back-end, GitHub, Back-end Development, SQL, Relational Databases, Infrastructure, CI/CD Pipelines, APIs
Full-stack Software Developer
2015 - 2016
Urbanclap
- 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: Elasticsearch, MongoDB, Node.js, Distributed Systems, REST APIs, Jira, Microservices, Amazon S3 (AWS S3), Amazon EC2, Docker, PostgreSQL, Microservices Architecture, Kibana, TypeScript, NestJS, REST, Back-end, GitHub, Back-end Development, SQL, Relational Databases, Infrastructure, Kafka Streams, CI/CD Pipelines, APIs
Software Engineer
2014 - 2015
HealthKart
- 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, Java, eCommerce, Spring, Distributed Systems, REST APIs, Jira, Microservices, Node.js, Amazon S3 (AWS S3), Amazon EC2, Docker, PostgreSQL, Microservices Architecture, Kibana, TypeScript, NestJS, JavaScript, REST, Back-end, GitHub, Back-end Development, SQL, Relational Databases, Infrastructure, Kafka Streams, CI/CD Pipelines, APIs
Experience
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.
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
https://codersrank.io/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.
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.com
Osperi provides customized beauty products based on your skin type and concerns. I did this website's complete back-end and front-end development with functionalities like eCommerce, doctor consultation, chat, and various other features. The stack is Node.js, MongoDB, AWS, Elasticsearch, and WiFiDog.
Captive Portal in Node.js Using WiFiDog
https://github.com/shank318/Wifidog-node-mongodb-auth-serverThe complete auth server is written in Node.js and MongoDB, which follows all the protocols of the WiFiDog auth server. It's a WIFI access connector for coffee shops, hotels, restaurants, spas, homestays, etc.
Jvaluate
https://github.com/shank318/jvaluateJava library to convert Arbitrary expression into relational query.
Audio/Video Conversation-based AI Technical Interviewer
Conduct real-world technical pair programming interviews with AI.
It takes a lot of time and effort to conduct pair programming with every candidate, and we end up using assessment platforms like HackerRank, Karat, etc, to filter candidates based on the problem-solving round.
We enable companies to conduct actual pair programming rounds using Generative AI, mimicking real conversations like humans over an audio/video coding platform.
It takes a lot of time and effort to conduct pair programming with every candidate, and we end up using assessment platforms like HackerRank, Karat, etc, to filter candidates based on the problem-solving round.
We enable companies to conduct actual pair programming rounds using Generative AI, mimicking real conversations like humans over an audio/video coding platform.
Education
2009 - 2013
Bachelor of Technology Degree in Computer Science
Uttar Pradesh Technical University - Lucknow, India
Skills
Libraries/APIs
Node.js, Protobuf, REST APIs, Quartz, ReactiveX, EJS, WhatsApp API
Tools
Jira, Open Rules Engine, Kibana, Kafka Streams, GitHub, RabbitMQ, IntelliJ IDEA, Sublime Text, GoLand, JBoss Drools, NGINX, ELK (Elastic Stack), Amazon Simple Queue Service (SQS), Terraform, Helm, Google Kubernetes Engine (GKE), Grafana
Languages
Go, TypeScript, JavaScript, Java, GraphQL, SQL, Python, Snowflake
Frameworks
NestJS, Spring Boot, gRPC, Spring, Next.js
Paradigms
Microservices Architecture, Rule-based Programming, Microservices, REST, Agile
Platforms
Docker, Firebase, Amazon Web Services (AWS), Apache Kafka, Kubernetes, Google Cloud Platform (GCP), Heroku, Amazon EC2
Storage
MongoDB, MySQL, Redis, Amazon S3 (AWS S3), PostgreSQL, Relational Databases, Elasticsearch
Industry Expertise
Accounting
Other
Technical Leadership, eCommerce, Prometheus, Distributed Systems, Payment Gateways, Architecture, Software Architecture, Fintech, Software as a Service (SaaS), CTO, Back-end, Back-end Development, API Integration, Leadership, Card Payments, Payment Processing, Digital Payments, Infrastructure, Team Leadership, CI/CD Pipelines, APIs, Redis Clusters, WebSockets, GitHub Workflows, OpenAI, Temporal, Chatbots, OpenAI GPT-4 API, Generative Pre-trained Transformers (GPT), OpenAI GPT-3 API, Containerization, Raft Consensus Algorithm
Collaboration That Works
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