Sanjay is available for hire
Hire SanjaySanjay Gandhi
Verified Expert in Engineering
Full-stack Developer
Mumbai, Maharashtra, India
Toptal member since June 22, 2016
Bio
Sanjay graduated from Harvard in 2010 with a BA in computer science. Afterward, he worked for five years at Tower Research Capital, a top high-frequency trading firm in New York City, developing their core trading infrastructure. Then, Sanjay founded the Y Combinator-backed fintech startup, Easyplan and scaled it to 250,000 users. As the CTO, Sanjay architected and built both the back and front end and ran DevOps.
Portfolio
Jupiter
Kotlin, Java, Spring Boot, PostgreSQL, Amazon DynamoDB, Kubernetes, Redis...
Easyplan Technologies Private
Python, Flask, Cordova, React, Redux, Redis, PostgreSQL...
Emersys Inc.
Cython, Scripting
Experience
Availability
Part-time
Preferred Environment
Jenkins, GitHub, Python, React, JavaScript, Flask, PostgreSQL, Redis, Amazon Web Services (AWS), Terraform
The most amazing...
...project I've coded is Easyplan, an investment app for beginner investors. We scaled to 250,000 users and I single-handedly built and managed all the tech.
Work Experience
Architect and Director of Engineering
2021 - PRESENT
Jupiter
- Led the account opening and payment teams for a leading neo bank in India and scaled our user base from 0-2.5 million bank account holders.
- Worked as a service owner for our most critical platform services (authentication, account opening, user management, and gateway) with a peak QPS of 4,000.
- Led operational excellence initiatives for our overall app, increasing uptime from 99 to 99.99%. This involved several performance enhancements in the core platform services I owned and extensive cross-team coordination across the company.
- Ramped up quickly on complex systems. Took over an existing account opening system within a month of joining and scaled us from 0-2.5 million accounts while fixing more than 20 critical bugs.
- Worked on tech ops with customer service leaders. Reduced our CPC by more than 50% and doubled our NPS.
- Managed key relationships with senior stakeholders at our banking partners, working with them to continuously improve their systems, uptime, and SLAs.
- Managed a team of 15 engineers across levels, responsible for their training, mentorship, and career growth. Mentored engineers from other teams frequently, on the request of their EMs.
- Architected several major infrastructure components, such as our authentication service and performance testing systems.
- Managed critical zero-downtime migrations and re-architectures, such as migrating more than 10 million user IDs from a monolith to a new user management service.
Technologies: Kotlin, Java, Spring Boot, PostgreSQL, Amazon DynamoDB, Kubernetes, Redis, Amazon Simple Queue Service (SQS), Apache Kafka, CDC, Application Security, Leadership, Agile, Mentorship, Team Mentoring, Back-end, Architecture, Microservices, Spring, Message Queues, Scripting, API Integration, System Architecture, Web Servers, Cloud Deployment
Full-stack Developer and Co-founder
2017 - 2021
Easyplan Technologies Private
- Developed a B2C fintech app that allowed users to invest in mutual funds and scaled it to 250,000 users. Received funding from Y Combinator. Ensured high availability (<4 hours of downtime in two years).
- Integrated with banks, payment gateways, and other financial service providers. Led relationships with various stakeholders at these companies.
- Worked with our product team to plan the development roadmap. Interacted frequently with users to understand their pain points.
- Managed a cross-functional team of six members, including one product manager, a developer, and four customer success executives.
- Optimized our key product metrics continuously through tech initiatives. Our new investor funnel had 2x the conversion and the lowest acquisition cost of every other investment app in the country. Scaled to $20 million in transaction volume.
- Built the back end using Flask, Celery, Redis, and PostgreSQL. Built the front end in React and Redux, including a custom conversational UI and several complex dashboards and charts.
- Ran DevOps with full IaC using Terraform and Docker. Set up Jenkins for CI/CD.
Technologies: Python, Flask, Cordova, React, Redux, Redis, PostgreSQL, Amazon Web Services (AWS), Terraform, Jenkins, Fintech, Amazon S3 (AWS S3), Data Architecture, Web Application Architecture, Architecture, AWS Lambda, SQL, CSS, CSS3, HTML5, HTML, APIs, Algorithms, Back-end, Front-end, Startups, Lean Startups, Message Queues, User Experience (UX), User Interface (UI), Scripting, Full-stack Development, API Integration, System Architecture, Web Servers, Cloud Deployment
Independent Contractor
2015 - 2015
Emersys Inc.
- Developed a fast Huffman encoding and decoding library in Cython for neuroscience researchers in Berkeley, CA.
Technologies: Cython, Scripting
Independent Contractor
2014 - 2015
Tower Research Capital Pvt Ltd
- Designed and developed integrated testing framework used for test trader to market flow for any market.
- Trained QA team members at headquarters to migrate an existing manual test cases to the new framework.
- Provided debugging and knowledge support to development, support, and QA due my deep knowledge of the entire system.
Technologies: C++, Scripting
Full-stack Developer
2014 - 2014
Dukibox.com
- Was a part of a two-person team that built and maintained a mid-size eCommerce website offering pet products.
- Architected the front and back end of a recurring subscription-based payments system, including support for PayPal.
- Developed front end and admin support for bank payments, a unique requirement for the Taiwanese market.
Technologies: Flask, Python, Full-stack Development
Infrastructure Developer
2010 - 2014
Tower Research Capital
- Designed and developed core components of a C++ high-frequency trading platform used by all trading teams.
- Worked directly with the lead architect to develop the firm’s order, risk management, and position tracking systems.
- Architected a major redesign of the firm’s position management system, allowing for complex position tracking.
- Architected and developed a protocol for fast distributed state sharing across any team’s trading servers.
- Found and fixed rare bugs in a complex multi-threaded code requiring a deep understanding of the entire system.
- Designed and developed the firm’s early-stage monitoring system, including a mobile app with real-time notifications.
- Worked on US FX development teams, writing code to interface with many markets globally with a high cost of failure.
Technologies: C++, Distributed Systems, Concurrent Programming, Architecture, System Architecture
Software Development Engineer Intern
2009 - 2009
Microsoft Corporation
- Developed a solution for UI design validation for the User Interface Platform team and Windows Experience Group.
- Designed a custom framework for expressing UI design rules, and encoded a rule set provided by the PM.
- Developed a C++ prototype for checking UI violations in real-time, using the Windows UI Automation API.
- Used a prototype to analyze the overall feasibility of an UI guideline validation and presented the findings to team of 6 PMs.
Technologies: C++
Experience
Easyplan Investment App
http://easyplan.inCordova-based mobile app for investment in low-risk mutual funds. As CTO, I built the app, launched it, and scaled it to 250k users. We are the most popular low-risk investment app on the Indian play store and have been funded by Y Combinator.
Accounting Code for Dukibox.com
I had the opportunity to contribute to Dukibox.com, a subscription-based service that provides monthly packages of delightful goodies for pet dogs. Specifically, I developed the core accounting code utilized on the back-end of Dukibox.com.
Fast Huffman Coding in Cython
I developed an exceptionally efficient Huffman encoder/decoder implemented in Cython. Once compiled, it seamlessly integrates as a module into Python scripts, enabling effortless importation and utilization.
Education
2006 - 2010
Bachelor's Degree in Computer Science
Harvard University - Cambridge, Massachusetts
2004 - 2006
International Baccalaureate Diploma in International Baccalaureate
Dhirubhai Ambani International School - Mumbai, India
Skills
Libraries/APIs
React
Tools
Terraform, Jenkins, Amazon Simple Queue Service (SQS)
Languages
SQL, Python, JavaScript, HTML, CSS, SCSS, Java, CSS3, HTML5, C++, Kotlin
Frameworks
Redux, Flask, Spring Boot, Spring
Paradigms
Microservices, Web Application Architecture, Distributed Programming, Concurrent Programming, DevOps, Web Architecture, Agile
Storage
Cloud Deployment, Redis, Amazon S3 (AWS S3), PostgreSQL, Amazon DynamoDB
Platforms
Amazon Web Services (AWS), Docker, AWS Lambda, Kubernetes, Apache Kafka
Other
Full-stack, Fintech, Scripting, API Integration, System Architecture, Web Servers, Cordova, Distributed Systems, Data Architecture, Infrastructure Architecture, APIs, AWS DevOps, Architecture, Message Queues, User Experience (UX), Full-stack Development, Algorithms, Operating Systems, Programming Languages, Compilers, Cython, Development, Back-end, Front-end, Startups, Lean Startups, CDC, Application Security, Leadership, Mentorship, Team Mentoring, User Interface (UI)
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