Software Engineer: Back-End · working across the stack on the BB App team at Capitec

I build the systems behind the screen.

I'm Lesedi Molemi, a software engineer living in Pretoria and working in Sandton. I build across the back end and front end of Capitec's Business Banking app, and write about what I build on the side.

See my work Read the blog

Writing

All posts →
From One Lambda to Four: How My Market Emails Grew Up 📈How my twice-weekly market update email went from one .NET Lambda to a Spring Boot Email API on AWS, and what I'd write differently nowBreakdown: Mapping any excel file into objectsA quick walk through the logic that maps any excel file into objectsMigrating over to Next.js, AWS and more...Updating my site and migrating to Next.js and AWSI tried an Open Source AI model for Image RecognitionHow my attempt at using an Open Source AI model went

Selected work

GitHub →
MICROSERVICES · JAVACustomer StatementsUpload, store and retrieve customer account statements. An API gateway fronts three Spring Boot services, authenticates every request against Dex (OIDC), stores files in S3 and caches pre-signed download URLs in Redis.Spring BootPostgreSQLRedisS3DockerView on GitHub →SERVERLESS · AWSStatement AnalysisBank statement upload and analysis. A Spring Modulith on Lambda with Cognito auth and Aurora, Textract for PDF extraction and Claude for insights, wired through SNS/SQS and provisioned across two regions with Terraform.Spring ModulithLambdaTextractTerraformReactView on GitHub →SERVERLESS · PYTHON · RUSTMarket FinancialsA market data platform on AWS Lambda: a containerised Python function serving financial statements and a Rust authoriser validating API keys against DynamoDB, deployed with Terraform and GitHub Actions.PythonRustDynamoDBTerraformGitHub ActionsView on GitHub →SPRING BOOT · AWS SESEmail APITemplate-driven market update emails rendered with Thymeleaf and sent through SES, running as a containerised Lambda.Spring BootThymeleafSESLambdaView on GitHub →

Career

From support to software engineering at Capitec.

  1. Oct 2026 - PresentSoftware Engineer: Back-End · Capitec Business BankBB Digital App Product team. Building out new product features across the back end and front end of the BB Banking App.
  2. Nov 2024 - Sep 2026Support Specialist · Capitec Business BankWhere I learned the codebase: resolved escalated client issues, shipped production fixes, worked on a front-end redesign in React and ran releases for the Business Banking app.