Serverless Loan Underwriting Decisioning Architecture using AWS Step Functions and a Compiler-Driven Decisioning UI

Saugat Pandey

Abstract: Underwriting of loans is a critical practice in the financial sector, and it requires careful evaluation of the identity of a borrower, creditworthiness, compliance level, and risk exposure before credit administration. The traditional monolithic and tightly-integrated underwriting platforms have bottlenecks related to scaling, integration with vendors, and regulatory traceability. In the given research, a serverless architecture of loan underwriting decision making is presented using AWS Step Functions, Lambda, API Gateway, DynamoDB, S3, CloudWatch, and Datadog to achieve an automated, compliant, and scalable workflow. In the proposed architecture, a compiler based Decisioning UI is proposed, which converts graphical underwriting workflows into executable AWS artifacts, thus allowing non-technical analysts to collaborate with experienced engineers to design and implement decision logic together. Procedural nodes (examples are: fraud screening, military status validation, OFAC compliance, and credit bureau retrieval are represented as reusable components, which are strongly typed and compiled by the compiler to similar Step Functions and Lambda artefacts. This architecture deems the utilization of caching, through DynamoDB, large payload management, through S3, and centralized visibility, through Datadog, which reduces vendor overhead, enhances transparency, and protects regulatory adherence. The document outlines the overall architecture, compiler pipeline and deployment plan, and strongly focused on cost optimization, performance, and auditability. Experimental analyses indicate that a server-less compiler-driven model may reduce the complexity and operational profile of infrastructural levels significantly without effecting the high demands of reliability, security and compliance that modern financial institutions bear.

Keywords: Amazon Elastic Step Functions, Serverless Architecture, Loan Underwriting, Compiler-Driven UI, Decision Automation, FinTech, Compliance, Cloud Computing, Workflow Orchestration, DynamoDB Caching

How to Cite?: Saugat Pandey, "Serverless Loan Underwriting Decisioning Architecture using AWS Step Functions and a Compiler-Driven Decisioning UI", Volume 14 Issue 12, December 2025, International Journal of Science and Research (IJSR), Pages: 123-141, https://www.ijsr.net/getabstract.php?paperid=SR251122050008, DOI: https://dx.doi.org/10.21275/SR251122050008