Secure iOS and fintech apps
Built and maintained Swift, Objective-C, Xamarin, MVVM, and MVVM-C applications across banking, commerce, sports, education, document scanning, and consumer utility products.
AI/ML - Security - iOS - Fintech
Sabbir Ahmed Saqlain
Software engineer working across secure iOS systems, AI/ML, LLM-powered OCR, RAG applications, fintech mobile platforms, cloud data security, and blockchain-based access control. I am open to new projects in iOS, AI/ML, LLM apps, RAG pipelines, identity verification, mobile security, fintech, and production-grade API integrations for teams looking for a reliable developer who can move from architecture to shipped product.
3.92 MS Computer Science GPA at New Jersey Institute of Technology.
71 Public GitHub repositories checked from the GitHub profile.
1M+ Active customers supported through fintech mobile work at UCB fintech.
IEEE Published research on malicious Android application detection using ML.
What I Build
My strongest work sits at the intersection of mobile engineering, applied machine learning, secure identity flows, and financial technology. I enjoy projects where correctness matters: secure authentication, liveness checks, document capture, OCR extraction, banking payments, encrypted data handling, and AI systems that need to be reliable enough for real users.
ML, LLM, OCR, and RAG
Developed LLM-based OCR flows, local RAG services with Ollama, FAISS, and embeddings, CoreML face detection, clinical ML pipelines, and model-backed mobile features.
Identity, cryptography, and cloud data
Focused on authentication protocols, cryptographic data protection, cloud data security, secure API integrations, blockchain access control, and privacy-aware system design.
Experience
A practical engineering path through startup leadership, secure identity systems, fintech iOS applications, enterprise banking, and teaching computer science at graduate level.
Jan 2026 - Ongoing
Engineering Manager, Consultant - Chakrie.com
Leads engineering planning and development for the Chakrie.com platform, including task prioritization, code review, deployment, reliability improvements, and product-team collaboration.
AI agents, LLM, Python web, VPS, AWS, PostgreSQL, iOS, AndroidApr 2026 - Ongoing
Software Engineer II - KONASL
Builds secure AI/ML and iOS capabilities for identity and fintech workflows, including NID capture with real-time guidance, LLM-based OCR extraction, secure liveness checks, GPU-backed inference, API integration, production deployment, and documentation.
LLM, Swift, MVVM/MVVM-C, REST APIs, iOS, AWSJan 2023 - Dec 2025
Graduate Teaching Assistant - New Jersey Institute of Technology
Supported course logistics, student questions, office hours, coding and debugging help, grading, project feedback, quizzes, and exams using clear rubrics.
Sep 2022 - Dec 2022
Software Engineer II, iOS - Optimizely
Delivered B2B commerce mobile application work with compliance, secure architecture, testing, documentation, and user support.
iOS, Xamarin, C#Jul 2021 - Aug 2022
Software Engineer, iOS - UAPY, UCB Fintech Company Ltd.
Developed a financial services app serving more than 1M active customers, integrating strong authentication, secure payment protocols, ML-based face detection, and cryptographic protection for transactions.
Sep 2019 - Jul 2021
Associate Software Engineer, iOS - Brain Station 23
Built and refactored secure banking applications including Citytouch, UNET Enterprise Banking, UCB One, AB Direct Internet Banking, and Modhumoti Digital Banking. Rewrote around 40 percent of an Objective-C codebase to improve stability and scalability.
Swift, Objective-C, MVVM/MVVM-C, REST APIs, WebRTC, WebSocketResearch And Engineering Focus
The CV and public GitHub profile show a consistent thread: secure data systems, applied ML, local AI assistants, retrieval pipelines, blockchain privacy, and mobile-first deployment.
Predicting ED Patient Outcomes
Built an end-to-end ML pipeline on MIMIC-IV ED data for patient mortality prediction, including cleaning, feature engineering, PCA plus K-Means clustering, SMOTE balancing, classifier benchmarking, SHAP interpretability, and Random Forest selection.
Local document question answering
Built a local RAG pipeline with Ollama, Llama 3.1 8B, FAISS vector search, nomic-embed-text embeddings, PDF/TXT/MD ingestion, text chunking, semantic retrieval, and a FastAPI service.
Access control for cloud data
Designed hybrid blockchain and cloud storage architecture for supply chain data, with decentralized access control, real-time revocation, and scalability for ML-driven analytics over encrypted datasets.
Face detection and identity verification
Developed live face detection modules for customer registration, trained custom CoreML models, optimized real-time performance, and integrated the model into iOS registration flows.
CV-Listed iOS App Store Work
This section comes from the PDF CV's "Other Projects (iOS App in App Store, Team Lead)" entries and highlights team-lead work across OCR, AI learning, AI media generation, education, and games.
AI Text Recognizer
Real-time handwriting and printed text OCR for iOS using Vision/CoreML, multi-language recognition, quick export, and App Store maintenance.
Smart Tutor - AI Powered Learn
AI study app for homework help, math, science, and writing problem solving, step-by-step answers, scanned questions, and quiz generation.
AI Art: Artify Image & Video
AI-powered image and video generation app for artwork creation, photo enhancement, and custom video style transformation.
BreakGame: Block Brick Break
Fast-paced brick-breaker arcade game for iOS with paddle control, progressive levels, power-ups, increasing difficulty, and smooth physics.
Kids Math Example Practice
Educational iOS app helping children practice addition, subtraction, multiplication, and division with unlimited examples and playful visuals.
BrainGrid: Puzzle Challenge
Logic puzzle game with grid-solving tasks, progressively harder levels, pattern connection, sequence solving, and brain-training challenges.
Article
Long-form technical writing on RAG, embeddings, vector databases, LangChain, LangGraph, evaluation, and production multi-agent AI systems.
Embeddings in RAG
Practical guide to embeddings, semantic search, chunking, vector storage, retrieval quality, and production tuning.
RAG Performance Evaluation
Validation guide covering retrieval, generation, end-to-end quality, human review, monitoring, latency, and cost.
View All Articles
Open the full Article section for vector databases, LangChain, LangGraph, and production multi-agent RAG guides.
Skills
A practical stack for shipping mobile, backend, AI, and security features from prototype through production.
LLM applications, RAG, supervised learning, deep learning, model optimization, CoreML, TensorFlow Lite, Scikit-learn, FAISS, Ollama, embeddings.
Swift, Objective-C, iOS, MVVM, MVVM-C, Xamarin, C#, Python, FastAPI, REST APIs, WebRTC, WebSocket, PostgreSQL.
Symmetric and asymmetric encryption, key management, authentication protocols, mobile security, access control, Docker, AWS, Hyperledger Fabric, Ethereum.
Open To Projects
I am available for selected new projects and consulting work where my background can help: secure iOS apps, fintech product engineering, AI/ML proof-of-concepts, LLM features, RAG document systems, OCR and NID extraction, liveness and face detection, backend API design, cloud deployment, and code review for production mobile apps. If you are searching for an iOS developer in Bangladesh, an AI/ML engineer for a practical product, or an LLM/RAG developer who understands security-sensitive workflows, this is exactly the kind of work I like to do.