Kaustav Chakraborty

This project aimed to modernize a large USA-based global insurance company's existing mainframe-based policy administration system using microservices architecture in Azure cloud infra. The project used IBM business process management as a business workflow system and the mainframe as the primary data source. The rest proxy services on the mainframe were built to source data for the business process management workflow through microservice-based choreography. The project has multiple integrations with IBM MQ, IBM Content Manager, and various in-house legacy systems.

ENGAGEMENTS
• Building, architecting, designing, and testing the product
• Customer orientation, the conceptualization of digital designs, and architecture
• Product feature prioritization
• Building initial framework to make the large volume deliverables through few developers without much technical challenge
• Product roadmap and plan creation
• Building integration strategy with legacy applications
• Product go-live roadmap
• Building CI/CD automated DevOps pipeline

Built a SaaS-based multitenant platform product using microservices in Azure, creating a blockchain-based interoperable platform for the biggest logistics company of CE and its customers' network. As the ideating architect of the product, I helped the customer set up blockchain COE. Built future digital roadmap to standardize the heterogeneous communications with customers, to create shipment transparency, automated order processing, integrated operational processes between cargo and multi-modal carriers, conformance testing, mitigate regulatory compliance, reconciliation, and real-time financial settlement. This product can transact using VC on did and can interoperate using blockchain platforms like Quorum and Fabric. The client SDK built for the platform makes it easy to integrate the platform into all different entities or organizations.

ENGAGEMENTS
• Architecting, designing, coding, and testing the product.
• Development and POC of VC and DID-based multi-blockchain interoperable platform.
• Winning ARB approval in setting up blockchain COE.
• Participated in CTO and CIO-level discussions.
• Building integration strategy with legacy applications.
• Onboarding of entities and automated deployment of multiple entities.

Conceptualization and development of microservice and blockchain-based citizen vault for one of the big countries in the Middle East, building a customized decentralized identity based on an Ethereum platform solution. The solution was used to integrate with other government services to identify citizens and store issued credentials of citizens by different government and private agencies.

ENGAGEMENTS
• Building framework and POC.
• Conceptualizing, creating architecture, coding, and testing DID-based ecosystem with a general blockchain platform.
• Defining microservice-based architecture; kickstarting the project; multiple entity onboarding strategies.
• Participating in customer discussions, requirement gathering, and technology consulting.

This project is to design and create a big financial network based on blockchain, microservices architecture, and data sharing through blockchain between multiple banks across geography within a big consortium to replace the current Swift messaging system with the new microservice-based backbone.

ENGAGEMENTS
• Designing and development of the initial framework.
• Designing a blockchain-based system.
• Channelization into large-scale development.
• Moving the initial AWS hosting into the private cloud.
• Code review, quality monitoring, security analysis, and performance analysis.

Various digital technologies evolved with the time that needed research, optimum usability, and performance evaluations. Also, so many new blockchain platforms have evolved since the year 2017. This was an accelerator within the organization to evaluate and explore the features and performance of various new technologies to build capability for the practice. It includes appraising the latest technologies to the customers and promoting them in various business development activities.

ENGAGEMENTS
• Exploration and evaluation of features of various digital technologies, including blockchain platforms.
• Development of accelerator frameworks and reusable codes for fast usage of new digital software and platforms.
• Creation of a custom-made decentralized identity (DID) solution.
• Performance analysis of various software and platforms.
• Gap analysis and platform fitment analysis.
• Building POC applications to explore platform features.

This project is to define a new smart contract language that is inspired by the Scala syntax and compiles to the Ethereum virtual machine fork. This project required full compiler development and testing.

ENGAGEMENTS
• Analysis and envisioning of Ethereum EVM-supported opcodes.
• Designing and developing grammar and parser using Bison and Flex.
• Designing and developing AST and semantic analyzer.
• Designing codegen and datagen visitors.
• Designing and developing test harness using Go.
• Testing and leading a team.

This was to do POC for natural language processing using neural networks to scan receipts and various other banking business documents and to summarize data from there to feed into the database for reporting.

ENGAGEMENTS
• Self-learning of artificial intelligence and natural language processing.
• Designing and developing using Python to establish machine learning.
• Designing and developing image processing from documents.

This project entailed developing and enhancing the internet payment gateway for the European wing of one of the large USA-based payment processing companies (acquirer). This engagement was for their business growth in EMEA, APAC, and LA regions. I mainly worked with Germany, India, and Australia initiatives to provide architectural solutions and provide technical consultancy to roll out IPG all across EMEA, APAC, and LA regions with needed features demanded by that region's businesses. We implemented a new architecture and design to modernize the internet payment gateway using scalable microservice-based products to cater to more load with automated deployment needs to cope with increasing traffic load.

ENGAGEMENTS
• Understanding client requirements.
• Coding design testing and review.
• Acted as a techno-functional lead of the team and owned all deliveries.
• Knowledge transition, helping and guiding the team to scale up to meet business needs.
• UML, RFE/RFI, technical architecture, and solution design using open stack technologies for various needs of businesses.
• Redesigned and created microservice-based architecture and design with auto-scalable needs within an on-premises data center.

This project is mainly to design and develop a centralized lightweight common highly configurable application framework composed of both Oracle and open-source technologies for a large financial company in the USA. All business applications across BUs in the organization were planned to be converted or developed using a custom-made Atom framework. Another big part of this engagement was to design and develop configurable security authorization and entitlement solutions. Oracle Entitlements Server was used in controlled-pull mode as an entitlement solution which was integrated with Atom framework using Spring Security.

ENGAGEMENTS
• Requirement understanding.
• Multiple POC, UML, RFP, solution design, and development.
• Developed and maintained the entitlement module using OES integrated with Spring security.
• Developed multiple tools for POC.
• Collaborated with Oracle support team, upgrades, and implementations.

This is a Salesforce integration project to automatically share customer data to a third-party brokerage account opening system. This engagement has two parts—migration of billions of customer data from the legacy Sybase database to Salesforce using SFDC data loader API and integrating multiple web applications with the Salesforce platform. For web security two-way SSL, SAML is used with SOAP-based web services.

ENGAGEMENTS
• Requirement analysis and design.
• Designed and developed middle layer architecture to interface between third-party systems and Salesforce for secure data exchange.
• Learning and development in Salesforce using APEX, SOQL, and WADL.
• Data analysis, re-engineering, and data migration using SFDC data loader.
• Third-party connectivity testing, integration testing, and security enablement.
• Provided UAT support.
• Production deployment planning and verification after deployment.

Travelport is a leading provider of the global travel industry. They are the owner of three major GDS systems in the world, Galileo, Worldspan, and Apollo. This project was meant to develop a configurable universal API product that can integrate all GDS of the globe and act as a universal travel platform. The core part of this project is to develop a web service-based middle layer that will expose various transactional services to any front-end apps like Orbitz and Makemytrip. Also, the project gives provision to create any customized agency and all its sub-layers like a branch, branch group, agent, account, account group, and traveler.

ENGAGEMENTS
• POC, R&D, technically helping team members to deliver on time.
• Coding, code reviews, peer reviews, and unit testing.
• Development, release planning, defining stories, analysis, planning, and estimation.
• Performance monitoring and analysis issue resolution.

This project was to build a new web-based 1Stop internet-facing car insurance application to modernize customer legacy mainframe-based applications. It involved creating and maintaining policy administration (PAS), billing and accounts receivable (BNR), document generation (DMS), customer information system (CIS), commissioning system (CMS) applications. Another part of the project was to build an external-facing internet application and middle layer service framework to consume the core 1Stop functionalities.

Engagements:
• Requirement analysis, use case preparation, coding, and development.
• Prepared unit test, system test, and UAT test plans.
• Onshore and offshore coordination.
• Setting up infrastructure and guidelines for the new maintenance project.
• Worked both as a developer and business analyst of the billing and accounts receivable system.
• Configuration management, problem management, and release management.
• Acted as the leading participant in client coordination and consultation.
• Played the main leading role in UAT planning and UAT execution.
• Provided nightly batch support periodically.

Involved in multiple projects in SCE engagement. Initially, I engaged in PowerBuilder migration of CSS application after that contributed to the development, enhancement, and support of core business app (CSS), call center app (CWO), and meter process automation (MPA) applications. Involved in the modernization of applications using java oracle stack.

Engagements:
• Requirement analysis, coding, unit testing, performance testing, and impact analysis.
• Leading modules, guiding team members, and reviewing deliverables.
• Production implementation after every release.
• Operational support.
• Onshore and offshore coordination.
• Change request implementations and production support.

The product was built and expanded on otbTRADE and it is essentially a decentralized ERC20 and BEP20 cryptocurrency exchange that combines the best of the traditional order book approach with a liquidity provider approach (Pancakeswap) where the users can trade and manage their assets efficiently on one platform. The platform also includes a lottery system for investors to increase gains.

RESPONSIBILITIES
• Smart contract development to create a fork of PancakeSwap
• Smart contract development for order book DEX
• Combining Pancakeswap with Orderbook
• Smart contract development for the lottery system
• Unit test cases using Truffle
• Manual testing

Developed a gas-optimized efficient NFT for Ethereum main net compatible with OpenSea and Rarible royalty payment.

FEATURES:
• Always mint random tokens.
• Max 5,000 tokens are in supply.
• Each wallet can mint a maximum of 12 tokens.
• Multiple presale periods with configurable starting times before the crowdsale starts.
• Only whitelisted addresses can participate in the presale.
• Mint price is 0.3 Ether per token.
• NFT reveal time is configurable by the owner and revealed after crowdsale started and posted immediately after mint.
• The owner can pause the minting token and stop revealing NFT anytime, even after crowdsale starts.
• 100 tokens are reserved for the owner that can be minted anytime.
• All payments are collected into the contract on mint function.
• Only Ethers are accepted as a payment method.
• The owner can withdraw the fund in the following percent—marketing 3%, community 11%, donations 12%, and the two owners each get 37%.
• Royalty payment of 10% on secondary sale paid to NFT creator.
• Secondary sale in OpenSea.

Developed a decentralized finance platform like DRIP Network that enables buying on presale, whitelist, and public presale. When the after-sales start, the presale token can be swapped for a sale token. A sale token could be staked to get interest and sold to get BUSD after swapping through PancakeSwap. Tax on tokens is also supported for any transfer.

RESPONSIBILITIES:
• Develop multiple token smart contracts
• Develop a staking smart contract
• Built the taxing smart contract
• Integrate with Pancakeswap for automated exchanges of SLDR to BUSD
• Hardhat-based automated test script
• Manual testing

Orsy is a new platform being built for citizen journalists or any average person to be able to upload streaming news coverage worldwide through their mobile phone. Once uploaded, based on the number of views and likes, journalists are compensated with a token called Orsy. Any viewer can choose to tip the news uploader, and any news agency can decide to hire Orsy platform journalists in an uberized manner.

MY ROLE:
• Advise the client on how to create token economics through the blockchain within the platform independently based on the supply and demand of the assets and services.
• Develop a financial model using the Orsy utility token with a real-world data model.
• Develop cash circulation and inflationary models envisioning real-world scenarios.
• Help the product manager build the use case in the project.
• Assist the client in streamlining ways to generate revenues in the platform.
• Advise the client with initial and future investments they need based on financial modeling and lay out ways to tackle various inflationary situations in the platform.
• Advise the blockchain developers with the contract design and suggest developing hooks for the platform owner to control cash flow and dividends.

This project was meant to create a platform based on the Tezos blockchain to pledge game development to the developers. Based on an individual's pledge, an NFT is awarded the pledge certificate. It also enlists the Born token into Tezos DEX.

MY ROLE:
• Initial conceptualization and design to introduce Tezos blockchain into the BlockBorn platform.
• R&D in the Tezos blockchain platform resources and use it to develop a system.
• Develop Tezos FA1.2 and FA2 standards tokens for BlockBorn.
• Develop an NFT certificate token for Tezos.
• Create a blockchain workspace with Ithcanet and Tezos Temple Wallet.
• Enlist the BlockBorn token in the Tezos DEX platform.
• Overall blockchain development and testing.

The Rematic Token (RMTX) created the Rematic V1 token using the PinkSale anti-bot token platform. It allowed the staking of RMTX tokens by their community and automatically distributed dividends using EGC (Evergrow coin). Users used to invest in RMTX through BUSD and PancakeSwap and get an EGC coin as a dividend, which they converted to BUSD through PancakeSwap in the BSC chain. The PinkSale anti-bot smart contract is directly integrated with PancakeSwap and generates auto dividend distribution logic.

The generated smart contract had flaws, primarily security and performance issues. A good worth of RMTX tokens was getting leaked because of an error in the PinkSale anti-bot smart contract. The dividend distribution process had a performance bottleneck and used to cause a large amount of loss through gas.

MY ROLE:
• Analyze, test, and identify the leakage and performance bottleneck in the RMTX v1 smart contract.
• Propose an alternate solution for making dividend distribution efficient.
• Help the client build a V2 smart contract through PinkSale.
• Simplify the V2 contract dividend distribution and eliminate the EGC token.
• Security auditing of the V2 contract.
• Generate automated test cases for the V2 contract.

Valuit is a decentralized finance platform that allows users to launch and trade assets and licensed securities tokens in a decentralized manner. The main objective of the Valuit product is to promote the use of blockchain to allow for transparency and efficiency when trading and offering asset tokens and securities. This project launched its ICO for VALU tokens and created a DAO platform through which investors or corporations could take loans in place of securities. It also facilitated projects to launch their own ICO and tokens, finance their projects, and collect dividends from project gains. All in a completely transparent autonomous way with community voting. It also creates its DEX for Valuit-launched platform tokens and project-specific tokens.

MY ROLE:
• Initial guidance and analysis to shape the requirements for blockchain adoption.
• Assist the client in choosing the blockchain platform.
• Develop smart contracts for VALU tokens and crowdsaling contracts for ICO.
• Shape up the requirements for platform application building (front-end and back-end).
• Design and develop upgradable smart contracts to implement the platform ecosystem for security tokens (ERC2535, 1400, 1410, 1594, 1643, 1644), voting, DEX, etc.

This project primarily involved creating a back-end system with composable NFT (ERC998) with multiple child NFTs and bidding token NFT. The project wants to implement a 3D citizen NFT which can hold multiple children NFTs Like Body, District, multiple Wearables, etc., to define a character for AR and VR applications.

MY ROLE:
• Requirement analysis and segregation in on-chain and off-chain data structure design.
• Composable 3D NFT (ERC998 ERC1155 Topdown) design and development with an animated composable image in OpenSea.
• Node.js, Inverse.js, Web3-based back-end API application design and development with Postgres off-chain database.
• Development of the React front-end application with Web3 integration to demonstrate end-to-end platform implementation.
• Development and integration with multiple wallets like Metamask, Trust Wallet, Coinbase Wallet, and Gnosis Safe wallet.
• Implementation of WalletConnect protocol in the front-end application.
• Deployment of the back-end API application into AWS.

This project was to do a functional and security audit of smart contracts for a new DEX (fork of uniswap) for a financial company and create web3 onramp application development.
I created reports, including code scanning summary, inheritance graph, function call graph, and data dependencies analyses. I also made constructor calls, storage orders and slots, security checks, etc.

The following checks were done during the security checks:

• Reentrancy
• Upgradability
• Patching to be done based on usage check (Echidna) or remove asserts etc.,
• ERC conformance
• Uninitialized local variables and memory
• Uninitialized Storage variables, Ether Lock, tx.origin
• Low-level ASM
• Unexpected sending of Ether to Arbitrary destinations, unchecked external calls, and leaks
• Pragma Directive
• Overflow and underflow
• Fallback and Receive
• Force-feeding check
• Unsafe Arithmetic
• Short Address
• Dos Attack
• Transaction order dependence, call stack depth, gas limits, and loops, including griefing
-Timestamp dependence, dangerous delegate calls, private information, and randomness
• mapping clearing
-Code patterns, Oracle Manipulation, if any

I created a sports trading platform where users could buy and sell teams from various sports worldwide, including volleyball, basketball, baseball, American football, soccer, handball, rugby, and ice hockey.

The platform allows payment deposits and withdrawals through Stripe, and the user gathers pennants (valued at 1 USD each). After getting pennants, users can buy teams. When a team wins, then, based on a blockchain-based immutable algorithm, the price goes up, which is related to the ratio of pennant volumes for the participating teams in a game. The platform has the ability to onboard leagues and teams through the admin portal, and once a game is onboarded, it's available for users to buy and sell.

The schedule and scores of games of any league are fetched from plug-play-based 3rd-party API, and once the scores are published, the system detects who won and lost, and accordingly, blockchain smart contract moves the prices of the teams. The platform also supports a rewards program with five tiers and a referral program. The project's back end is fully governed by a private blockchain Hyperledger Fabric deployed into the AWS cloud in a scalable way.