~/portfolio/cacilda-langa
Data & Software Engineering

I build software and data systems that solve practical problems. My work has taken me from SQL and reporting into data engineering, backend development, cloud deployment and applied AI. I work mainly with Python, SQL and TypeScript, and have built systems involving data pipelines, APIs, PostgreSQL and MySQL, AWS, document processing, OCR, analytics and AI-enabled services.

View systemsBackground
Data EngineeringBackend EngineeringCloudApplied AICum Laude BICT
PythonTypeScriptSQLAWS LambdaS3CloudFrontCDKPostgreSQLMySQLFlaskFastAPINext.jsReactPaddleOCROpenAI WhisperGroqCloudflare WorkersDockerPrismaLeaflet.jsReportLabPandasOpenCVYAMLSupabaseGitHub ActionsMicrosoft Entra IDPythonTypeScriptSQLAWS LambdaS3CloudFrontCDKPostgreSQLMySQLFlaskFastAPINext.jsReactPaddleOCROpenAI WhisperGroqCloudflare WorkersDockerPrismaLeaflet.jsReportLabPandasOpenCVYAMLSupabaseGitHub ActionsMicrosoft Entra ID
Background

Building Data & Software Systems

I joined my internship expecting to work mainly with reporting and data. As I became more involved, I started taking on larger technical problems and building software to solve them.

Over the course of my internship, I have worked on systems ranging from data pipelines and operational dashboards to document processing services, APIs, cloud deployments and AI-enabled applications.

A lot of my work starts with a fairly simple question: how can we make this process work better?

Sometimes that means taking data from one system and making it available somewhere else. Sometimes it means replacing a manual process with an application. Other times it means taking a new technology and figuring out whether it can solve a problem the business is currently struggling with.

I enjoy working across the whole process, from understanding the problem and designing the solution to writing the code, deploying it and supporting it afterwards.

I primarily work with Python, SQL and TypeScript, with experience across AWS, Flask, FastAPI, PostgreSQL, MySQL, React and Next.js.

Context

My current role has given me the opportunity to work across software engineering, data engineering, cloud systems, analytics and applied AI within the South African energy sector.

Education
Bachelor of Information and Communications Technology (BICT)
Durban University of Technology, Durban, South Africa
Completed May 2026
Cum Laude78% Final Cumulative Average
Relevant Coursework
Business Intelligence IIIMachine Intelligence IIIAlgorithms & Data Structures IIInformation Management IIInformation Assurance & Security IISoftware Engineering IIIPlatform-Based Development IIIResearch Project
Research Project
Youth Social Relief of Distress Identity Fraud Detection

My final research project investigated the use of biometric approaches to detect identity fraud in South Africa's youth-focused SRD grant.

  • ›Conducted a systematic literature review using PRISMA.
  • ›Investigated facial recognition and deep learning approaches for identity fraud detection.
  • ›Compared a CNN baseline with a Siamese Neural Network.
  • ›Evaluated model performance using accuracy, precision, recall and F1-score.
Certifications
Azure Data Fundamentals (DP-900)Microsoft · July 2026

The certification covered core data concepts and Azure data services, including relational and non-relational data, data analytics and common Azure data workloads.

Training
AWSAWS Skills Center: Becoming a Cloud PractitionerAWS Skills Center, Cape Town, South Africa · 2026

I attended the four-part instructor-led Becoming a Cloud Practitioner programme at the AWS Skills Center in Cape Town.

Course Parts
Part 1: AWS Cloud Basics

Covered the fundamentals of cloud computing and AWS, including core AWS services, cloud concepts, pricing and the shared responsibility model.

Part 2: Compute, Networking, and Account Strategies

Covered AWS compute and networking services, account structures and strategies for organising AWS environments.

Part 3: Identities, Security, and Monitoring the AWS Cloud

Covered identity and access management, security concepts, monitoring and approaches to operating AWS environments securely.

Part 4: Advanced Cloud Services

Covered additional AWS services and more advanced cloud concepts, building on the foundations of compute, networking, identity and security.

Production Systems

All eight, in detail

Every system below is in production or in active daily use. Expand any card for engineering detail.

Call Analysis Service

A service that analyses recorded calls and generates summaries of what each call was about.

GroqTypeScriptNode.jsMySQL
＋Problem · Engineering Work · Impact
Problem

Instead of someone having to listen through recordings to understand what each call was about, the service uses Groq to analyse the calls and produce summaries.

Architecture
Call recording → analysis → summary → database
Engineering Work
  • ›Built the service using TypeScript and Node.js.
  • ›Integrated Groq for AI-powered call analysis.
  • ›Stores generated summaries in MySQL.
Impact

Turns a time-consuming manual review process into something that can be handled much more efficiently.

sourceCode is in a private company repo. Happy to walk through it.

Solar Inverter Data Pipeline

An AWS-based data pipeline and query service for solar inverter telemetry.

AWS LambdaAmazon S3TypeScriptPostgreSQLPrisma
＋Problem · Engineering Work · Impact
Architecture
Structured data → ingestion → parsing and normalisation → PostgreSQL → query API
Engineering Work
  • ›Takes structured inverter data, processes and normalises it, then stores it in PostgreSQL.
  • ›Lambda handles processing and S3 provides cloud storage as part of the ingestion workflow.
  • ›Query functionality makes inverter readings available as a data service.
Impact

Makes inverter readings easier to work with and removes the need for manual handling of the source data.

sourceCode is in a private company repo. Happy to walk through it.

Data Maps Dashboard

An interactive geospatial analytics dashboard for exploring geographic and market data across South African municipalities.

PythonFlaskPostgreSQLLeaflet.jsGeoJSONCloudflare Workers
＋Problem · Engineering Work · Impact
Architecture
Relational data → application layer → geographic visualisation
Engineering Work
  • ›Brings together different datasets and displays them on interactive maps.
  • ›Worked on the database structure, data integration, backend and visualisation.
  • ›Implemented filtering and interactive exploration of geographic and market data.
Impact

Makes it possible to explore locations, geographic boundaries and market information in one place.

sourceCode is in a private company repo. Happy to walk through it.

Company Marketing Website

A production corporate website built using Next.js, React and TypeScript.

Next.jsReactTypeScriptAWSCloudflare
＋Problem · Engineering Work · Impact
Engineering Work
  • ›Developed the website using Next.js, React and TypeScript.
  • ›Implemented responsive user-facing functionality and website components.
  • ›Configured production deployment and supporting cloud infrastructure.
Impact

Gave the business a modern production website and provided hands-on experience with frontend development and production deployment.

sourceCode is in a private company repo. Happy to walk through it.

OCR & Document Processing Service

A document-processing service that extracts information from identity documents and other business documents.

PythonFlaskPaddleOCROpenCVVision Language Models
＋Problem · Engineering Work · Impact
Architecture
Document image → image processing → extraction → validation → structured data
Engineering Work
  • ›Combines PaddleOCR, computer vision and vision language models for document extraction.
  • ›Validation logic improves the reliability of the extracted information.
  • ›Image preprocessing improves extraction from difficult document images.
  • ›Automatic cleanup of uploaded files so that document images are not retained unnecessarily.
Impact

Reduces the amount of manual information capture required when processing documents.

sourceCode is in a private company repo. Happy to walk through it.

PDF Generation Engine

A YAML-driven document generation service that converts structured data and templates into PDF documents.

PythonFlaskReportLabAmazon S3YAML
＋Problem · Engineering Work · Impact
Architecture
Structured data → YAML template → document rendering → PDF → cloud storage
Engineering Work
  • ›Documents are defined using YAML templates rather than custom PDF-generation code for every document.
  • ›Supports reusable components: tables, headings, signatures and dynamic fields.
  • ›Nine document templates, 15 component types and 66 automated tests.
Impact

A new document can be defined through configuration without changing the underlying generation engine.

sourceCode is in a private company repo. Happy to walk through it.

Sales Validation System

A data validation and reconciliation tool that cross-checks records from multiple sources and produces discrepancy reports.

PythonFlaskMySQLPostgreSQLPandas
＋Problem · Engineering Work · Impact
Engineering Work
  • ›Compares records from multiple sources and identifies discrepancies.
  • ›Produces reports that can be reviewed by the relevant teams.
  • ›Integrated multiple relational databases for record verification.
Impact

Replaced a largely manual reconciliation process with something that can be run consistently and repeatably.

sourceCode is in a private company repo. Happy to walk through it.

Fleet Management & Vehicle Tracking System

An authenticated web application for monitoring vehicle and fleet information through an interactive dashboard.

Next.jsReactTypeScriptPostgreSQLMicrosoft Entra IDLeaflet
＋Problem · Engineering Work · Impact
Engineering Work
  • ›Combined vehicle data with an interactive map for monitoring fleet information.
  • ›Implemented authenticated access using Microsoft Entra ID.
  • ›Worked across the application, database integration and data synchronisation.
Impact

Provides a centralised interface for viewing and monitoring fleet information.

sourceCode is in a private company repo. Happy to walk through it.
Technical Focus

Technologies I have shipped with

I focus on the technologies and engineering areas most relevant to the systems I build rather than maintaining an exhaustive list of every technology I have encountered.

Languages

PythonSQLTypeScript

Data

ETLData IngestionData ValidationData ReconciliationData Modelling

Databases

PostgreSQLMySQL

Backend

FastAPIFlaskREST APIsMicroservices

Cloud

AWSCloudflare

Applied AI

Large Language ModelsOCRComputer VisionDocument Processing

Frontend

ReactNext.js

Engineering

System DesignAPI DesignTestingCI/CDGit
approach.ts
How I work

Engineering Approach

01

Start with the problem

I try to understand what actually needs to be solved before deciding what technology to use.

02

Understand the data

For data-heavy problems, I want to understand where the data comes from, what shape it is in, how reliable it is and what needs to happen to it before it can be used.

03

Build the simplest useful solution

I prefer practical solutions that can actually be deployed and maintained rather than adding complexity for its own sake.

04

Deploy and learn

Getting something into production teaches you things that are difficult to discover during development. I use that feedback to improve the system.

05

Take ownership

I like being involved beyond just writing the code. That includes understanding requirements, making technical decisions, deploying systems and helping resolve issues afterwards.

interests.md
Where I want to go

Areas of Interest

Data Engineering

Building reliable pipelines and data systems that move, transform and validate data for applications and analytics.

Backend Engineering

Building APIs, services and microservices that connect data, applications and business processes.

Cloud Engineering

Working with cloud infrastructure and deploying applications and data services using AWS.

Applied AI

Finding practical ways to use AI, OCR and computer vision to improve existing business processes.

Analytics

Turning operational data into dashboards and applications that people can actually use to make decisions.

Contact

Let's Talk

I'm interested in Data Engineering, Backend Engineering and Cloud Engineering opportunities where I can work on real-world data and software systems.

If you want to talk about something I've built, a technical problem you're working on, or an opportunity, feel free to get in touch.

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